The Green Building Handbook Volume 4

The Green Building Handbook South Africa Volume 3 www.greenbuilding.co.za Green Building Handbook South Africa Volume 4 www.greenbuilding.co.za

The

Green Building Handbook

South Africa Volume 4

The Essential Guide

ISBN 978 0 620 45240 3.

04

www.greenbuilding.co.za www.greenbuilding.co.za

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Green Building

Conference & Exhibition 25th - 26th July 2012 Sandton Convention Green BuildingCentre

Sustainability

Week alive2green Sustainability

25 -29 JULY 2012 SANDTON SVICC

25 -29 JULY 2012 SANDTON SVICC

Week

alive2green

Building and the built environment are a major contributor to climate change, arguably the most significant, and should be centre stage in the process of driving down energy. Governments can invest to in climate renewable energy Building anddemand the builtfor environment are a major contributor change, butarguably these technologies will not be able to cope with present levels of demand , the most significant, and should be centre stage in the process of great swaths of which is for simply wasted. driving down demand energy.

Governments can invest in renewable energy but these technologies will not be able to cope with present levels of demand , great swaths of which is simply wasted.

In the discourse on adapting the climate change, the property and construction sectors will likely be most heavily

impacted. We are facing a rising high tide line and a high sea line that’s even higher due to the expected increase in the frequency of severe weather events. Ad to this the possible need to have to build to a higher structural specification for the same is alsothe predicted to occurthe less frequently but with greater intensity drastically In the reason. discourseRainfall on adapting climate change, property and construction sectors will likely be mostincreasing heavily the needimpacted. to captureWe rain may see being that will need strategy to achieve this. arewater, facingwhich a rising high tideit line andregulated a high sea lineevery that’sbuilding even higher due toa the expected increase in the frequency of severe weather events. Ad to this the possible need to have to build to a higher structural specification for Featuring keynote presentation frompredicted award winning Stefan Zopp (Partner Jean Nouvel Architects) and many the same reason.

Rainfall is also to occurarchitect less frequently but with greater intensity drastically increasing the other international, and localmay speakers, in an regulated innovativethat quality over quantity format, structured to include need to capture regional rain water, which see it being every building will need a strategy to achieve this.highly interactive multi-disciplinary workshops. Don’t miss the 6th annual issue of this market leading event.

Featuring keynote presentation from award winning architect Stefan Zopp (Partner Jean Nouvel Architects) and many other international, regional and local speakers, in an innovative quality over quantity format, structured to include highly interactive multi-disciplinary workshops. Don’t miss the 6th annual issue of this market leading event.

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Conference & Exhibition 25th - 26th July 2012 Sandton Convention Centre

Other leading events taking place during Sustainability Week Other leading events taking place during Sustainability Week Sustainable Transport Seminar 2012

Vision Zero Waste Seminar 2012

Sustainable Mobility Seminar 2012

Green Business Seminar 2012 Vision Zero Waste Seminar (focus: business leadership and return2012 on

(focus: Infrastructure, the Freight Mix, Logistics, Alternative engines and fuels)

Sustainable Transport 2012 (focus: urban design – density,Seminar pedestrian and (focus: oriented, Infrastructure, the Freight Mix, Logistics, cyclist Alternative engines public transport, cityand carsfuels) and user pools etc) Sustainable Mobility Seminar 2012 Demand Side Water Efficiency (focus: urban2012 design – density, pedestrian (focus: industrial water and Seminar cyclist oriented, efficiency) public transport, city cars and user pools etc)

Energy Efficiency Seminar 2012 Demand Sideenergy Water Efficiency (focus: industrial efficiency) Seminar 2012 (focus: industrial water efficiency)

Renewable Energy Seminar 2012 (focus: removing impediments to broad Energy Efficiency Seminar 2012 implementation)

(focus: ewaste and other primary business streams)

(focus: ewaste investment) and other primary business environmental streams)

Green Home Magazine Fair 2012 Green Business Seminar 2012 (trade show aimed at the household consumer business and return on cars) –(focus: everything fromleadership green houses to green environmental investment)

Social Housing Seminar 2012 (focus: Green Home value Magazine Fairto2012 building property and a means (trade show aimed at the household consumer eradicate poverty) – everything from green houses to green cars)

Photovoltaic Society Conference Social Housing2012 Seminar (focus:2012 broad(focus: and Exhibition

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building property value and a means to opportunities for photovoltaic in SA, latest eradicate poverty) technologic advancements)

Renewable Energy Seminar 2012

Photovoltaic Society Conference and Exhibition 2012 (focus: broad

(focus: removing impediments to broad implementation)

opportunities for photovoltaic in SA, latest technologic advancements)

Sustainability Week Sustainability 25 -29 JULY 2012

SANDTON SVICC

Week

25 as-29 JULY 2012 If you wish to participate a delegate, exhibitor or sponsor, or if your your organisation would like to run an event as part of Sustainability week please contact us on info@alive2green.com or call us at 021 447 4733 SANDTON SVICC Visit www.sustainabilityweek.com | www.alive2green.com If you wish to participate as a delegate, exhibitor or sponsor, or if your your organisation would like to run an event as part of Sustainability week please contact us on info@alive2green.com or call us at 021 447 4733 Visit www.sustainabilityweek.com | www.alive2green.com

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Forward The built environment, in particular infrastructure development, features prominently in the diagnostic review of the National Planning Commission and the National Development Plan for South Africa. The CSIR is a national research institute that focuses on the new imperatives of government as contained in the medium term strategic framework and the outcomes. Of importance in the research focus of the CSIR is development of new materials for the built environment (i.e. construction material), new technologies, renewable resources and reducing environmental impacts.

Furthermore, research is also focused on water and energy efficiencies and finding overall technological solutions for reducing South Africa’s carbon and water footprints. Already the CSIR is embarking on its water sustainability flagship project to address the challenges of the water security aspects, i.e. quality, quantity and efficiencies, in South Africa as a whole and to assist government where needed on strategic interventions. In addition, the green buildings initiative will help the public and private sectors to reach their national targets and contribute positively to the reduction of green-house gas emissions.

Dr. Cornelius Ruiters Executive Director: Built Environment CSIR

Therefore, the CSIR Built Environment is continuing with its world class research in the following research impact areas: road pavement engineering (i.e. bitumen replacement), coastal and port engineering, architectural engineering, construction materials and methods (i.e. green brick research initiative, cementitious replacement materials), urban and regional planning (i.e. urban dynamics laboratory), sustainable human settlements, transport planning and freight logistics (i.e. green logistics; energy minisation in transport and supply chain management) and network asset management systems (i.e. public transport systems, traffic safety management, intelligent transport management systems, bridge management systems, and overloading systems). Thus, through the aforementioned world class research impact areas the CSIR is working toward solving built environment problems and contributing towards the knowledge base of South Africa and the world and instrumental in the management and transfer of this knowledge.

Thus, in the context of the research impact areas, the world class research focus areas and the CSIR flagship programmes the CSIR Built Environment unit is pleased to endorse the publication of the Green Building Handbook Volume 4. This publication gives the direction, impetus and contribution for major positive changes in the planning and development solutions within the construction industry in South Africa. In addition, this handbook will further contribute to minimise and/or solving the major problems and concerns in the construction and building industry.

the green building HANDBOOK

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Forward In recent years, much attention has been focused on the environment and climate change and on the requirement for architects to design towards sustainability. It is pleasing to see that there has recently been more focus on the importance of the social pillar of sustainability which is resulting in an increase in formal dialogue that is directed outside of the building and towards the block, the suburb and ultimately the city. This is where South Africa’s problems will be solved and this is where the architect can play a leading role.

SAIA aims to promote excellence in architecture but seeks also to contribute to the enhancement of society and the environment – these are stated missions. There is therefore a moral and organisational duty for SAIA to actively facilitate the process of changing paradigms and we are only able to do this with the support and assistance of both the public and private sectors.

The Green Building Handbook is an example of a project that is positively changing the way that architects and other built environment professionals as well as policy makers are thinking, and SAIA welcomes the arrival of the 4th Volume of the Handbook. We urge other public and private organisations to commit their support to this on-going project so that we can harness the collective intelligence and influence that is necessary to drive change.

Fanuel Motsepe President SAIA

the green building HANDBOOK

7

S er v i ci ng you r E nv i ro n men t

R e d u c ing O wning a nd O pe rating Cost Im p rove Comfor t Le ve ls Ex te nding Equipme nt Life Cyc le

For enquiries: 087 802 9976 Website: www.aircare.co.za Offices: 1 Marlborough Drive, Springfield, Johannesburg, 2190

abso lu te ser vice.

PEER REVIEW REVIEW Alive2green has introduced and is committed to peer reviewing a minimum number of published chapters in all Sustainability Series handbooks. The concept of Peer review is based on the objective of the publisher to provide professional, academic content. This process helps to maintain standards, improve performance, and provide credibility.

ALIVE2GREEN PEER ALIVE2GREEN PEERREVIEW REVIEWPROCESS PROCESS The Publisher and the Editor allocate a reviewer to an article and then send it to the reviewer who is well acquainted with the topic. Reviewers return an evaluation of the work to the Editor, noting weaknesses or problems along with suggestions for improvement. The Editor notes the reviewer’s recommendations and will either publish the article without changes, request that the author amend the article in accordance with recommendations or reject the article but encourage revision and invite resubmission.

The Editor evaluates reviewer submissions and is under no obligation to accept recommendations.

The Editor may also add his or her opinions and recommendations to those of the reviewer before passing these back to contributors. Peer reviewed articles may not necessarily have incorporated all recommendations made by the reviewer but are likely to have been amended from the original version.

Alive2green is proud to have embarked on the journey of peer review and now strives to achieve certain objectives in this process which include, but are not limited to: -

Extremely high standards of published material Sustainable Transport & Mobility Handbook Acceptance of handbooks in academic institutions, including as prescribed text books Increased publicity and exposure for handbooks in global academic circles Sustainable Increased exposure for contributors and editors within academic, industry and peer-review circles Water Resource Handbook Increased quality of learning texts for Alive2green online learning modules which are based on handbook content.

Sustainable Sustainable Transport & Mobility Energy Resource Handbook - Relevant and extensive coverage for advertisers within the handbooksHandbook and online.

The

South Africa Volume 2

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Waste Revolution

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South Africa 2009/10

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Waste Revolution

The Guide to Sustainable Waste Management South Africa Volume 1

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Transport & Mobility

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Volume 3

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South Africa 2009/10

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THE SUSTAINABILITY SERIES HANDBOOKS More than fifty thousand people in South Africa will read at least one of the Handbooks in the ‘Sustainability Series’ this year. The 5 Handbooks in the series are published by alive2green in a high quality A5 format and are available for purchase online at www.alive2green.com/handbooks.

The Sustainability Series Handbooks tackle the key areas within the broader context of sustainability and include contributions from South Africa’s best academics and researchers.

The Handbooks are designed for government and business decision makers and are produced in Volume format where each new Volume builds on the previous Volume without necessarily replacing it.

The Sustainable Transport and Mobility Handbook and the Green Building Handbook deal with two sectors that are the largest contributors to greenhouse gasses .The Water and Energy Handbooks tackle the issues and solutions that South African’s face with two of our most important Resources and finally the Waste Handbook deals with the principles concerned with Waste minimization and ultimately Waste eradication.

The Handbooks also profile some of the top companies and organisations that are represented in the each important sector.

The

Green Building Handbook

South Africa Volume 1

The Essential Guide

The

Sustainable

The

Handbook

Handbook

Transport & Mobility South Africa Volume 1

The Essential Guide

The

The

Water Resource

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South Africa Volume 1

The Essential Guide

Handbook enquiries: info@alive2green.com Advertising enquiries: sales@alive2green.com

Energy Efficiency South Africa Volume 1

The Essential Guide

Waste Revolution

The

South Africa Volume 1

Handbook

The Guide to Sustainable Waste Management

South Africa Volume 1

Renewable Energy The Essential Guide

The

Green Building

GENERAL MANAGER SALES Debbie Zeelie

South Africa Volume 4

SALES ADMINISTRATION Wadoeda Brenner

Handbook

The Essential Guide

PROJECT LEADER Glenda Kulp ADVERTISING EXECUTIVES Jennifer Benjamin, Louna Rae, Nazeem Hoosen, Neil Heldsinger

EDITOR Llewellyn van Wyk CONTRIBUTORS Al Stratford, Dr. Dirk Conradie, Faatiema Saalie, Graham Young, Llewellyn van Wyk, Marianne Strohbach, Mauritz Lindeque, Naalamkai Ampofo-Anti, Santie Gouws, Tichaona Kumarai,Wim Jonker Klunne

CHIEF EXECUTIVE Gordon Brown

PEER REVIEWERS Prof Andre de Villiers, Llewellyn van Wyk

DIRECTORS Gordon Brown Andrew Fehrsen Lloyd Macfarlane

LAYOUT & DESIGN Rashied Rahbeeni

PRINCIPAL FOR AFRICA & MAURITIUS Gordon Brown

EDITORIAL Siann Silk

PRINCIPAL FOR UNITED STATES James Smith PUBLISHER

ADMIN MANAGER Suraya Manuel EDUCATION & STRATEGIC MARKETING Cara-Dee Carlstein

www.alive2green.com www.greenbuilding.co.za

ADMINISTRATION Ruth Basson

The Sustainability Series Of Handbooks

PHYSICAL ADDRESS: Suite 207, Building 20 Waverley Business Park 1 Kotzee Road Mowbray Cape Town South Africa 7705

SBN No: 978 0 620 45240 3. Volume 4 first Published February 2012. All rights reserved. No part of this publication may be reproduced or transmitted in any way or in any form without the prior written consent of the publisher.

The opinions expressed herein are not necessarily those of the Publisher or the Editor. All editorial contributions are accepted on the understanding that the contributor either owns or has obtained all necessary copyrights and permissions.

IMAGES AND DIAGRAMS: Space limitations and source format have affected the size of certain published images and/or diagrams in this publication. For larger PDF versions of these images please contact the Publisher.

TEL: 021 447 4733 FAX: 086 6947443 Company Registration Number: 2006/206388/23 CHAPTER IMAGES Vat Number: 4130252432 123rf stock photography, ESP Photography, Llewellyn van Wyk

DISTRIBUTION AND COPY SALES ENQUIRIES distribution@alive2green.com INTERNATIONAL FRANCHISE ENQUIRIES info@alive2green.com ADVERTISING ENQUIRIES sales@alive2green.com PAPER PRINTER

Endorsers:

THE GREEN BUILDING HANDBOOK

11

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editor’s note The end of 2011 marked a step-change in South Africa’s progress down the sustainable building and construction path: Government announced three major initiatives that will have far-reaching implications on building practices in the future.

The first initiative was to gazette the new energy efficiency in building regulations: as you will know by now, this came into effect in November 2011, and while there are likely to be many projects that will receive exemption due to their progress status, the middle of this year should provide indications of what its impact on building energy performance is likely to be.

The second initiative was the announcement by Government that it had adopted a National Green Building Framework for South Africa, a framework that it is expected will guide Government with regard to its own estate development and management including new build, renovation, and leases, but also set in place steps to drive the private sector, including regulation and possible incentives.

The third initiative was the announcement by Government of its intention to develop a database of South African construction products with a view to introducing eco-labelling of construction products in the future.

These are momentous initiatives and will significantly change the development direction of the South African construction and property industries. As almost all the delegates to the Public Works workshop held at COP-17 in Durban noted, future generations will look back on these initiatives as a critical moment in South Africa’s progress toward sustainable building and construction.

There can also be little doubt that as the agreements made at COP-17 in Durban are further expanded, the pace of change with regard to the transition to a green economy and the adoption of adaptation and mitigation strategies within the built environment will increase steeply.

It is with this in mind that the content of this volume was deliberated.

A word that featured prominently at COP-17 in both verbal presentations and circulated texts was ‘resilience’: this is noteworthy in itself as it recognises that the ‘luxury’ of debating sustainability concepts has been replaced by the very real threats posed by changing climatic and environmental conditions. That we are entering a phase of less than benign climatic conditions is common cause: the debate is about determining the consequences of a harsher climate and preparing for the anticipated impacts on every sphere of life.

The Editor of this publication, Llewellyn van Wyk, sets the scene around which this debate is taking place. The main purpose of his chapter Building Resilient Human Settlements in a Climate of Change is to 1) note the impacts of climate change on human settlements and vice versa, and 2) propose design and institutional strategies to improve the resilience of human settlements to withstand these impacts or at least reduce the vulnerability of human settlements to these impacts. This chapter constructs a Human Settlement Resilience Framework and interventionist strategies. These strategies are based on the premise that resilience can be built into human settlement development.

In furtherance to this notion, two chapters speak to the critical role of the natural environment in sustaining human development. In the first of these chapters Ecology and the Built Environment Marianne Strohbach writes about the symbiotic relationship between ecological health and human well being: the objective, in this chapter, she notes, is to explain some of the most important aspects of the green building HANDBOOK

13

editor’s note why biodiversity and ecosystems matter and to clarify how the most common aspects of urbanisation affect ecosystems. An improved understanding of ecological processes can facilitate the integration of both human needs and nature in domesticated landscapes, while taking ecological concerns arising beyond the boundaries of such landscapes into consideration. Such inclusive planning should be able to buffer developments against chance events that have always shaped nature and that can be expected to increase in magnitude in the future due to global change.

In the second of these chapters Landscape Architecture Graham Young writes about the role of landscape design in developing a sustainable future. The premise, as articulated by Van der Ryn and Cowan, is that if we are to create a sustainable world – one in which we are accountable to the needs of all future generations and all living creatures – we must recognize that our present forms of agriculture, architecture, engineering, and technology are deeply flawed. To create a sustainable world, we must transform these practices. We must infuse the design of products, buildings and landscapes with a rich and detailed understanding of ecology.

The chapters that follow elaborate on this theme from a building design perspective. Dr. Dirk Conradie in Climate Zones and Weather Files argues that to design energy efficient buildings using the correct combination of passive design strategies such as insulation, thermal mass and natural ventilation it is necessary to understand the particular climate very well. To perform a quantified building performance analysis by means of simulation software a detailed set of quantified climatic data is required. We know that climate is the accumulation of consistent weather patterns over a period of time, and thus it is critical to determine those climatic maps and zones as accurately as possible in the first instance, and to determine what future climatic maps and zones may be in the second instance.

One of the most effective strategies in passive design is the use of natural ventilation and daylight.

Faatiema Salie, in her chapter Maximising Passive Ventilation, describes optimal strategies with regard to natural ventilation using an experiment carried out at the CSIR Innovation Site in Pretoria, while Dr. Dirk Conradie in his chapter Optimising Daylight in South Africa: A Case Study demonstrates how optimising daylight can reduce energy consumption during building operation.

It is well known that the building envelope plays a pivotal role in energy performance: given the significance of this building element, and the debate raging around highly insulated buildings versus thermal mass, Tichaone Kumirai and Dr. Dirk Conradie describe the findings of an analysis undertaken on the subject in their chapter Thermal Mass versus Insulated Building Envelope Design in Six Climatic Zones in South Africa. Their findings are critical for the development of a better understanding between energy efficiency and thermal comfort, and notes that a one-size-fits-all approach is not useful or appropriate for South Africa.

Given the pronouncement of the government with regard to eco-labelling, Naalamkai AmpofoAnti’s chapter Lessons for South Africa from Global Trends in Environmental Labelling of Buildings and Construction Products provides a critical insight into the issues that are required to inform the implementation of such a scheme.

Concrete remains one of the most widely used materials in the building and construction industry: cement manufacture is also one of the largest contributors to greenhouse gas emissions. In her chapter Environmentally Sustainable Concrete Structures, Santie Gouws articulates some of the industry interventions in reducing its GHG contributions.

The introduction of energy efficiency building regulations places new obligations on building designers with regard to reducing energy demand and supplementing energy supply from renewable energy sources. Wim Klunne expands on these notions in his chapter SANS 10400:- XA 2001: Application of the National Building Regulations Part XA: Energy Efficiency in Buildings/Renewable Energy. the green building HANDBOOK

15

PROFILE

Nicholas Plewman Architects Nicholas Plewman Architects was founded and is directed

by Nick Plewman. He has welded a life time passion for the wilderness to two decades of design and project management experience in remote and sensitive environments. To this have been banded the skills of qualified architects, project and cost managers and technologists.

The practice has completed over 35 projects across Southern and East Africa for both public and private clients and has been published in several books and magazines such as Architectural Digest and Conde Nast Traveller. We provide design and project implementation that is uncompromisingly innovative and ecologically sustainable in any environment from inner city to the remotest wilderness.

OUR COMPANY ETHOS • Uncompromising ecological responsibility • Sophisticated, original design • Energy neutrality and sustainable resourcing • Deriving style from aesthetic integrity that refrains from cliché ,waste and wantonness • Respecting tradition while exploring the dynamic opportunities of modernism and technology CONTACT US Tel: (011) 482 7133 • Fax: (011) 482 3170 www.plewmanarchitects.co.za

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editor’s note Lastly, two specific challenges facing human settlements is waste disposal and energy supply: Mauritz Lindeque argues that the two problems can be solved by making use of waste to generate energy in his chapter Waste to Energy.

With the uptake of sustainable building and construction activities more and more examples are becoming available for evaluation: wherever possible use has been made of case studies to better illustrate what technologies are used and how they have performed over time. This principle will be expanded on in further issues of the Handbook.

Adaptation and mitigation strategies are critical to our continued existence on Earth: it thus behoves environmental designers to focus their creative abilities on developing responses to the challenges facing the planet. We hope that this publication will contribute to that development.

Lastly I wish to thank all of those who have contributed to this publication, from writing the writing thereof all the way to its final production.

Llewellyn van Wyk Editor-at-Large,

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Contents 22 Chapter 1 Building Resilient Human Settlements in a climate of change 36

Chapter 2 Ecology and the built environment

48 Chapter 3 Landscape Architecture- Ecological Consciousness 60 Chapter 4 Maximising Passive wind Driven Ventilation: A case study 74 Chapter 5 Lessons for South Africa from Global trends in environmental labelling of buildings and construction products 100 Chapter 6

Optimising Daylight in South Africa: A case study 124 Chapter 7

Environmentally Sustainable Concrete Structures 138 Chapter 8 Waste to Energy - Bio Gas and Landfill Gas from Anaerobic Digestion 156 Chapter 9 University of Fort Hare: New Auditia and teaching Complex: East London Campus

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Building a green and eco-friendly future

MAGNA BOARD The Eco-Friendly Partitioning, Ceiling, Cladding and General Building Board for Interior and Exterior use Magnastruct is the supplier of Premium MgO (Magna Board) throughout Africa • non-toxic • mould & mildew resistant • fire resistant • impervious to water • • promotes healthy environment • recyclable • acoustic qualities • • thermal insulation • insect resistant • cost effective • durable •

HEADOFFICE Tel: +27 21 551 8855 Email: info@magnastruct.co.za Web: www.magnastruct.co.za

SALES Carl Schlettwein (SD) Mobile: +27 78 075 7995 Email: carl@magnastruct.co.za

Contents Special Section: 166 Chapter 10 SANS10400:-XA2001: Application of the National Building Regulations Part XA: Energy Efficiency in Buildings/ Renewable Energy 180 Chapter 11

Designing for South African Climate and weather 200 Chapter 12 Thermal Mass Vs. Insulation Building Envelope Design in Six Climatic Regions in South Africa

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chapter 1: Building Resilient Human Settlements in a Climate of Change

Building Resilient Human Settlements in a Climate of Change Llewellyn van Wyk Pricipal Researcher Built Environment CSIR

Introduction

The main purpose of this chapter is to 1) note the impacts of climate change on human settlements and vice versa, and 2) propose design and institutional strategies to improve the resilience of human settlements to withstand these impacts or at least reduce the vulnerability of human settlements to these impacts.

This chapter constructs a Human Settlement Resilience Framework and interventionist strategies.

These strategies are based on the premise that resilience can be built into human settlement development.

Background and Context

Living conditions – economic, social, environmental, and institutional – are changing on Earth.

This is not new, nor is it unique. The economic, social, environmental and institutional world constitutes a dynamic system, always in transformation from one state to another, sometimes smoothly and sometimes turbulently. However there is sufficient scientific consensus that anthropogenic impacts are resulting in an alarming degree of climatic, environmental and social change beyond rates experienced over the last 650 000 years (IPCC2007).

Global temperatures cycle between geological intervals of warmer global average temperature known as Interglacial Periods, and periods of colder global average temperature, known as Glacial Periods. Long glacial periods are therefore separated by more temperate but shorter interglacials.

During these past interglacials, where the climate more or less matched present day temperatures, the tundra (vast level treeless Arctic region where subsoil is frozen) receded towards the poles. As the tundra recedes it gets replaced by forests. This alternating cycle of floral and faunal expansion and retraction enables palaeontologists to study the climatic conditions prevalent at the time and the age of the particular interglacials (Kottak 2005).

Periods do occur within an interglacial where conditions are optimal, known as the climatic optimum of an interglacial, and this generally occurs during the middle part of the interglacial. The climatic optimum is preceded and followed by periods that are less favourable although it is still better than the conditions found in the preceding/succeeding glacial.

The current Holocene interglacial period, which commenced about 11 400 years ago (the end of the Pleistocene which lasted 2.5 million years) and in which we now find ourselves, experienced its climatic optimum roughly 3000 BC-500BC, resulting in an environmentally benign period highly supportive of human development. This period coincides with the transition out of the Stone Age to the Bronze Age and into the Iron Age. Our current climatic phase following this optimum is still within the same interglacial (the Holocene).

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The history of ancient Mesopotamia, coinciding as it did with the Bronze Age, begins with emergence of urban societies during the Ubaid Period (ca. 5300 BC). It is also perhaps not coincidental that in historical archaeology the ancient literature of the Iron Age includes the earliest texts preserved in manuscript tradition, including the oldest parts of the Hebrew Bible.

What distinguish our current climate of change from previous periods of change are two factors – human consumption growth, and anthropogenic induced environmental impacts.

The global population breached 7.0 billion in November 2011. Over half of this population live in poverty, and over half live in cities (and there is a strong correlation between the two). There has therefore been a concentration of population within urban areas: there are now 21 megacities in the world (UNEP 2011). Urbanisation generally improves standard of living resulting in higher rates of resource consumption: it is not coincidental that global GDP has increased by 74 per cent over the past 20 years (UNEP 2011).

The natural environment goes through cycles of growth and decline in response to climate change: however what is different now is the coupling of anthropogenic and climate change impacts on the natural environment. The sheer ‘weight’ or footprint of the current human consumption on natural resources (resource depletion), the reduction in biodiversity (replaced by mono-agriculture), and the influence of climate change on ecosystem health and distribution, is projected to result in an extinction event (Woolridge 2008).

Resilience

In environmental terms ecosystem resilience can be defined as “the capacity of an ecosystem to tolerate disturbance without collapsing into a qualitatively different state that is controlled by a different set of processes” (Holling 1973). An ecosystem demonstrates resilience by withstanding shocks and the ability to rebuild itself. Disturbance of sufficient magnitude or duration may profoundly affect an ecosystem and may force it to a threshold point beyond which a different set of processes and structures predominates (Folke et al 2004). One such disturbance is human activities including reduction of biodiversity, exploitation of natural resources, pollution, land-use, and anthropogenic climate change (Folke et al 2004).

Resilience can also be applied to social systems: resilience in psychology refers to an individual’s ability to cope with stress and adversity, or what is commonly referred to as a person’s ability to ‘bounce back’ (Masten 2009). Research indicates that resilience is the result of an individual’s ability to interact with their environments and the processes that either promote well-being or protect them against the overwhelming influence of risk factors (Zautra et al 2010).

When applied to human settlements resilience has been defined as “the capacity and ability of a community to withstand stress, survive, adapt, bounce back from a crisis or disaster and rapidly move on. Resilience needs to be understood as the societal benefit of collective efforts to build collective capacity and the ability to withstand stress” (ICLEI 2011a), and “the ability of a system, community or a society exposed to hazards to resist, absorb, accommodate to and recover from the effects of a hazard in a timely and efficient manner, including through the preservation and restoration of its essential basic structures and functions” (ICLEI 2011b).

The ICLEI (2011) submits that urban resilience is therefore the ability of urban systems to withstand certain levels of stress by: • Having flexible systems to absorb sudden shocks and slow onset of events; • Distributing stress across systems and avoiding single pressure points; • Restoring functionality in a timely manner to contain loss and avoid disruption; 24

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• Having substitutable systems if a major loss in functionality occurs; • Designing systems that safely fail to avoid catastrophic failure; and • Developing the ability to identify problems and building capacity to deal with them, establish priorities and mobilise resources to respond, adapt, and rapidly move on.

The current interdisciplinary discourse on resilience is now studying the interactions of humans and ecosystems via socio-ecological systems, and the need for shift from the maximum sustainable yield paradigm to environmental management which aims to build ecological resilience through resilience analysis, adaptive resource management, and adaptive governance (Walker et al, 2004).

It is thought that there have been five mass extinctions in the last 540 million years when over 50 per cent of animal species died (Sepkoski and Raup 1982). A mass extinction is characterised by a sharp drop in the diversity and abundance of macroscopic life (Nee 2004).

Notwithstanding these five events, the Earth has been able to recover, albeit over millions of years.

And each recovery has demonstrated an outburst of new specie development and growth (Benton 2004; van Valkenburgh 1999).

Projections of ongoing specie loss point to the potential of a sixth mass extinction (Woolridge 2008; Jackson 2008). The Living Planet Index (LPI) is used as an indicator of the state of global biological diversity based on trends in vertebrate populations of species from around the world: between 1970 and 2007 the index fell by 28 per cent suggesting that anthropogenic influences are degrading natural ecosystems at an unprecedented rate (LPI 2010).

Figure 1.1: Living Planet Index Source: http://www.maps.grida.no

While it is likely that the Earth would recover from such a sixth extinction (based on evidence from the previous five) the future of terrestrial specie, including Homo Sapiens, is not clear. Given that the greatest driver of this unprecedented global warming is anthropological in origin, logic would suggest that the risk of a sixth extinction could be reduced. The ability to survive this type of event requires human resilience and since the dominant location of the specie is in urban areas, by implication the ability that is sought could be called human settlement resilience.

The resilience of human settlements will be supported if the causes of mass extinctions can be identified. The relationship between mass extinctions and causes was summarised by MacLeod (2001) as follows: Flood basalt events – involves the formation of large igneous provinces which produce dust and particulate aerosols which inhibit photosynthesis; emit sulphur oxides which are precipitated as acid rain causing specie poisoning; and emit carbon dioxide resulting in sustained global warming.

Sea-level falls – reduces the continental shelf area (the most productive part of the oceans) the green building HANDBOOK

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sufficiently to cause a marine mass extinction, and disrupt weather patterns sufficiently to cause extinctions on land.

Asteroid impacts – the impacts from large enough asteroids or comets cause food chains to collapse both on land and at sea by producing sufficient dust and particulate aerosols to inhibit photosynthesis.

Sustained global cooling – kills many polar and temperate species while forcing others to migrate reducing the area for tropical species, and makes the Earth more arid by locking up moisture in ice.

Sustained global warming – has the opposite effect of cooling i.e., tropical species migrate thereby reducing the area for polar species, makes the Earth wetter, and possibly causes anoxic events in the oceans. There is sufficient evidence to confirm sustained global warming as a cause of extinctions (Mayhew, Jenkins, and Benton, 2008).

Anoxic events – are events in which the middle and even upper layers of the ocean become deficient or totally lacking in oxygen.

Hydrogen sulphide emissions from the seas – in which warming disturbs the oceanic balance between photosynthesising plankton and deep-water sulphate-reducing bacteria resulting in massive emissions of hydrogen sulphide which poisons life on land and in the oceans (Kump, Pavlov and Arthur, 2005).

Oceanic overturn – is a disruption of thermo-haline circulation which lets surface water (which is more saline than deep water because of evaporation) sink down, bringing anoxic deep water to the surface resulting in the death of most oxygen breathing organisms inhabiting the surface and middle depths (Wilde and Berry, 1984). High levels of carbon dioxide have caused global warming in the past, and influenced ocean circulation and how that warmth was distributed around the globe. The Late Cretaceous Epoch is a perfect example of greenhouse climate on Earth and mimics the conditions currently manifesting: carbon dioxide levels are rapidly approaching levels most recently experienced during ancient greenhouse times (Macleod et al, 2011).

Plate tectonics – continental movement can cause or contribute to extinctions through initiating or ending ice ages; altering climate through changed ocean and wind currents; exposing seaways and land bridges, and creating super continents which reduces the continental shelf, the species-rich portion of the ocean.

Anthropogenic influences on disruption events

There are at least two major impacts of anthropogenic origin which impact negatively on ecosystem resilience namely agriculture and human settlements. Recent research suggests that in the US about 50 per cent of the warming that has occurred since 1950 is due to land use changes in the form of clearing forests for crops and cities rather than to the emission of greenhouse gases made up predominantly of carbon dioxide, methane, nitrous oxide, and halocarbons (Georgia Institute of Technology, 2009).

Agricultural activities displace indigenous biodiversity and replace it with monoculture crops, such as wheat, maize, and fruit. In addition, the use of pesticides and herbicides further undermines the resilience of the remaining ecosystem. Large-scale farming production is also dependent on an energy-intensive supply chain, a significant contributor to greenhouse emissions.

Human settlements also displace indigenous biodiversity, but replace it with concrete and tar and, where planting is done, generally with alien vegetation.

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Figure 1.2: Reconstructed before and after view of Manhattan Island, New York Source: http://www.strangecosmos.com/

Fossil fuel burning for energy in buildings and transportation account for 23 per cent and 31 per cent of total carbon emissions in South Africa (cidb 2009). However, fossil fuel is also consumed to pump water (along the whole supply chain) and sewerage (again along the whole supply chain).

An appropriate mix of government regulation, energy savings technologies and behavioural change could substantially reduce carbon dioxide emissions from the built environment (UNEP 2007).

These two anthropogenic impacts increase with population growth and/or income, in terms of land use change, increasing food production, extracting raw materials, and providing shelter. Despite China’s efforts to reduce their carbon emissions, emissions increased between 1992 and 2007 largely on the back of infrastructure investment and its energy intensive supply chain such as steel and cement production (UEA, 2011). With the world population expected to breach 7 billion on 1st November 2011, and 9 billion by 2050, the global extinction crisis for animals and plants imperilled by overpopulation’s effect on habitat, water, air and other natural resources is expected to increase (Center for Biological Diversity, 2011).

Building resilient human settlements

This nexus between people and planet can therefore be described as a reciprocal relationship with disruption events impacting on both sides: major disruption events as a result of natural causes increases the vulnerability of both the planet and people, and so will anthropogenic contributions to typical causes of disruption events as listed earlier. This nexus is also the focus of research on building resilience in a climate of change.

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From the above the following interventions need to be implemented if human settlements are to become resilient, i.e., less vulnerable to disturbance events.

1) Reduce the loss of biodiversity 2) Reduce the exploitation of natural resources 3) Reduce pollutants 4) Eco-management of land use 5) Reduce anthropogenic contributions to climate change 6) Building in flexibility and substitutable systems to reduce failure and promote recovery.

In the Global Change Grand Challenge National Research Plan, South Africa, four major cross-cutting knowledge challenges and 15 key research themes are identified (DST 2009). The four cross-cutting knowledge challenges are: • Understanding a changing planet • Reducing the human footprint • Adapting the way we live • Innovation for sustainability This provides a useful framework to use to focus on building resilient human settlements. Using the research findings from above, the four major cross-cutting intervention areas and the corresponding key strategies can be described as indicated in Table 1.1 below.

Table 1.1: Framework for Building Resilient Human Settlements

Understanding socio-ecological systems

Reducing human settlement footprint

Adapting the way we live

Innovating for resilience

Observation and monitoring

Net-zero greenhouse gas emissions

Denser mixed-use urban development

Passive technologies (natural heating and cooling, lighting, ventilation)

Dynamics of ecosystem and human settlement interaction

Net-zero potable water consumption

Transit-oriented development (bike, bus, rail)

Active technologies (intelligent lighting and hvac, phasechange materials)

Linking land use change, climate change and disturbance events

Net-zero waste production

Re-establishing biodiversity in urban areas

Developing bio-based materials

Improving model predictions at different scales (urban, events)

Net-zero biodiversity loss

Reducing resource consumption

Solar technology

Food and water security

Net-zero toxic emissions (VOC, ODP)

Reducing vulnerability to disturbance events (sea-level rise, flooding, heat, drying, precipitation, wind)

Preparing for rapid change and disturbance events

Conclusion

Building human settlement resilience is wholly within our capability: all of the technology required and the enabling policies are do-able. There are areas, most notably in the science of earth systems, and the socio-ecological interactions where our knowledge is insufficient. Similarly, the modelling technology and the efficiency ratios of solar energy generators, requires further development. But principally the pathway to resilience is known.

The biggest hurdle to success is located in a willingness to adapt the way we live: will our species have the resolve to make the adjustments, and will it do so in time? Early signs emanating from civil society are that there is a groundswell of recognition that all is not as it should be. It may just signal a changing of the guard.

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References

Benton, M.J. (2004). “6 Retiles of the Triassic”. Vertebrate Palaeontology. Blackwell. ISBN 0045660026. Online http://www.blackwellpublishing.com/book. asp?ref=0632056371.

Center for Biological Diversity, (2011). “Global Population Passes 7 Billion, Crowding Out Imperiled Animals, Plants; Species Face Mass Extinction.” Online http:// www.enn.com/press_release/3867/ Cidb (2009). Greenhouse Gas Emission Baselines and Reduction Potentials from Buildings in South Africa, (p. 27). Pretoria: CIBD/UNEP. DST (2009). Global Change Grand Challenge National Research Plan, South Africa. Pretoria: Department of Science and Technology.

Folke, C., Carpenter, S., Walker, B., Scheffer, M., Elmqvist, T., Gunderson, L., Holling, C.S. (2004). “Regime Shifts, Resilience, and Biodiversity in Ecosystem Management”. Annual Review of Ecology, Evolution, and Systematics 35: 557–581. doi:10.1146/annurev.ecolsys.35.021103.105711 Georgia Institute of Technology, (2009). “Reducing Greenhouse Gases May Not Be Enough To Slow Climate Change.” Science Daily. Retrieved September 27, 2011.

Online http://www.sciencedaily.com/releases/2009/11/091111083055.htm Holling, C., (1973).”Resilience and stability of ecological systems.” Annual Review of Ecology and Systematics 31:425. Doi:10.1146/annurev.ecolsys.31.1.425 ICLEI (2011a). “Towards urban resilience”. Online http://www.iclei.org/ Source: ICLEI 2011.

ICLEI (2011b). “Towards urban resilience”. Online http://www.iclei.org/ Source: United Nations International Strategy for Disaster Reduction, UNISDR Terminology on Disaster Risk Reduction (2009).

IPCC (2007). Climate Change 2007: Synthesis Report. International Panel on Climate Change, Online http://www.ipcc.ch/ Jackson, J. B. C. (Aug 2008). “Colloquium paper: ecological extinction and evolution in the brave new ocean”. Proceedings of the National Academy of Sciences of the United States of America 105 Suppl 1: 11458–11465. Bibcode 2008PNAS..10511458J Kottak, C., (2005). Window on Humanity, New York: McGraw-Hill.

Kump, L., Pavlov, A., and Arthur, M., (2005). “Massive release of hydrogen sulphide to the surface ocean and atmosphere during intervals of oceanic anoxia.”

Geology v.33, p.397-400. Online http://geology.geoscienceworld.org/cgi/content/abstract/33/5/397 LPI (2010). Living Planet Report 2010. Online http://www.wwf.com/ Macleod, K., Londono, C., Martin, E., Berrocoso, A., and Basak, C., (2011). “Changes in North Atlantic circulation at the end of the Cretaceous greenhouse interval.”

Nature Geoscience, 2011; DOI: 10.1038/ngeo1284.

MacLeod, N., (2001). “Extinction!” Online http://www.firstscience.com/home/articles/earth/extinction-page-3-1_1258.html Masten, A., (2009). “Ordinary Magic: Lessons from research on resilience in human development”, Education Canada 49 (3): 28-32. Online http://www.cea-ace. ca/sites/default/files/EdCan-2009-v49-n3-Masten.pdf.

Mayhew, P., Jenkins, G., and Benton, T., (2008). “A long-term association between global temperature and biodiversity, origination and extinction in the fossil record”. Proceedings of the Royal Society B: Biological Sciences. 275 (1630): 47-53. Online http://www.rspb.royalsocietypublishing.org/content/275/1630/47. full Nee, S. (2004). “Extinction, slime, and bottoms”. PLoS biology 2 (8): E272. doi:10.1371/journal.pbio.0020272.

Raup, David M. and Sepkoski, J. John, Jr. (1982). “Mass extinctions in the marine fossil record”. Science 215 (4539): 1501–3. Bibcode 1982Sci...215.1501R UEA (2011). Growing CO2 Emissions from China due to Construction. Study undertaken by the University of East Anglia. Online http://www.uea.ac.uk/mac/ comm/media/press/2011/October/chinaemissions UNEP (2007). Buildings and Climate Change: Status, Challenges and Opportunities. Sustainable Building and Construction Initiative, United Nations Environment Programme, Nairobi.

UNEP (2011). Keeping track of our changing environment: From Rio to Rio+20 (1992-2012). Division of Early Warning and Assessment (DEWA), United Nations Environment Programme, Nairobi.

Van Valkenburgh, B. (1999). “Major patterns in the history of carnivorous mammals”. Annual Review of Earth and Planetary Sciences 26: 463–493. Bibcode 1999AREPS..27..463V Walker, B., Holling, C. S., Carpenter, S. R., Kinzig, A. (2004). “Resilience, adaptability and transformability in social–ecological systems”. Ecology and Society 9 (2): 5. Online http://www.ecologyandsociety.org/vol9/iss2/art5/.

Wilde, P., and Berry, W., (1984). “Destabilization of the oceanic density structure and its significance to marine ‘extinction’ events.” Palaeogeography, Palaeoclimatology, Palaeoecology 48 (2-4); 143-162. Online http://www.marscigrp.org/ppp84.html Wooldridge, S. A. (9 June 2008). “Mass extinctions past and present: a unifying hypothesis”. Biogeosciences Discuss (Copernicus) 5 (3): 2401–2423. doi:10.5194/ bgd-5-2401-2008 Zautra, A.J., Hall, J.S. & Murray, K.E. (2010). Resilience: A new definition of health for people and communities. In J.W. Reich, A.J. Zautra & J.S. Hall (Eds.), Handbook of adult resilience (pp. 3-34). New York: Guilford.

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PROFILE

City of Johannesburg The Cosmo City Climate Proofing Programme

The City of Johannesburg has identified the efficient use of energy as key for both uplifting communities, responding to the national power crisis as well as mitigating the impacts of climate change.

The City of Johannesburg implemented a ‘Climate Proofing’ Programme in Cosmo City low-income homes. Climate proofing involves promoting development that reduces the risks of climate change. The project involved the roll out of low pressure Solar Water Heater (SWH) units, installation of isoboard ceilings, distribution of energy efficient lights as well as planting of greenery (Trees, grass and shrubs) to 770 Reconstruction and Development Programme (RDP) homes in Extension 2 of Cosmo City. The project was funded by the Danish Development Agency.

Cosmo City is located near Kya Sands, Johannesburg, 25 kilometres northwest of the Johannesburg CBD. Cosmo City was chosen for this climate change programme due to the strong focus on Cosmo City on environmental sustainability.

The Cosmo City Climate Proofing Programme aims to contribute towards creating more livable, resource efficient and resilient urban communities through promoting energy conservation, alleviating energy poverty and demonstrating the performance and efficiency of renewable energy and energy efficiency technologies.

Above: Solar Water Heaters

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PROFILE

Above: Isoboard ceiling with a Compact Fluorescent Lamp (LFLs) The benefits of the project • Minimised electricity costs; • Promotion of behavioural change by encouraging residents to conserve electricity to save money and the environment; • Improvement on thermal comfort inside the houses; and Decreased energy demand; • Improvement of the Cosmo City environment through planting of greenery, offering shades, nutrition, run-off reduction and local biodiversity enhancement; • Green job creation and skills development by training and employing the local

community to install the interventions.

Above: Greenery

Contact Details:

City of Johannesburg Environmental Management Department 118 Jorissen Street, Traduna House, Braamfontein Tel: 011 587 4201 Email: joburgconnect@joburg.co.za Website: www.joburg.co.za

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chapter 2: Ecology and the built environment

Ecology and the built environment

Urbanisation involves one of the most extreme forms of land alterations and significantly affects the functioning of ecosystems and the services they provide to humans and other life on earth. The impacts of the built environment have been summarised as modifying natural landscapes, having an enormous effect on biodiversity – loss of indigenous ecologies - and introduction of invasive exotic species, contributing to global environmental change, negatively affecting water and air quality, being a source of substantial amounts of various types of waste as well as modifying hydrological cycles and aggravating soil erosion (Kibert et al. 2000). Often, these impacts are only acknowledged at the site of developments, but they in fact reach far beyond city borders as natural habitats are fragmented, isolated or degraded, hydrological systems in watersheds are disrupted and energy and nutrient cycles are greatly modified (Alberti 2005).

There is an increased interest in ecology of studying urban areas. Yet, study results typically simplify impacts of urban structures to such an extent that they are not useful to urban planners and managers.

Hence, strategies devised to minimise ecological consequences of urban growth often fail to identify the key underlining mechanisms that link urban pattern impacts to ecosystem function and the trade-offs that exist among different ecological processes are poorly understood (Alberti 2005).

The objective, in this chapter, is to explain some of the most important aspects of why biodiversity and ecosystems matter and to clarify how the most common aspects of urbanisation affect ecosystems.

An improved understanding of ecological processes can facilitate the integration of both human needs and nature in domesticated landscapes, while taking ecological concerns arising beyond the boundaries of such landscapes into consideration. Such inclusive planning should be able to buffer developments against chance events that have always shaped nature and that can be expected to increase in magnitude in the future due to global change.

Why bother about biodiversity?

Biodiversity is most commonly understood as the number or type of species present, at most including their genetic diversity. However, biodiversity also refers to the diversity of ecosystems present, including the structure of the communities (understood as the proportion and arrangement of species on a landscape) and the ecological processes that are part of such ecosystems. Species within an ecosystem play specialised roles, thus to maintain one species, the functional partner species needs to be maintained as well.

Functioning ecosystems as a whole - biotic and abiotic components - provide valuable services usually taken for granted – apart from providing us with raw materials, food and medicines, other services include pollination, flood control, water and air purification, nutrient cycling, pollution reduction, disease prevention, mitigation of extreme events and many more. Most of these services cannot be replaced by technological substitutes. The annual value of ecosystem services to man has been estimated as nearly twice the gross national product of all worlds’ economies combined (Costanza et al. 1998). the green building HANDBOOK

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Components of functional ecosystems

Species interactions and functions

Species occur in populations, populations of different species within an ecological community interact, and numbers of individuals fluctuate over time due to predation, herbivory, parasitism, mutualism and competition. The relative amount of individuals of one species to another, as well as the total diversity of species, is deterministic of a functioning and resilient ecosystem.

Mutualistic species benefit from the presence of other species for their optimal growth and reproduction. Many plant species depend on particular specialist insects or animals for pollination or niche requirements.

Naturally dominant species represent an important ecological function that can be upset if such species decline significantly. Thus the notion that annihilating a species in one area is acceptable as it occurs widely in other areas may have far-reaching consequences. The same applies to keystone species – these species are naturally not that abundant, but ecologically they may play a significant role, such as providing habitat for many smaller species. Many dominant and keystone species are ecosystem engineers – capable of modifying their immediate environment or regulating the population of other species. The identification of such species and the incorporation of measures to protect these in new developments will help to ensure that many of the associated species are also protected, whilst the ecosystem will retain at least some functionality.

Commonly impact assessments focus on rare and endangered species and legislation requires that sites with such species present be protected – often raising the question why such often very small species are so important? Conservation of rare species will only be effective and of use if such populations are continuously monitored. A sudden decline of such species is the first definite indicator that the ecosystem they are living in is deteriorating or non-functional. Identifying and eliminating the origin of this decline timeously may prevent the costly degradation of valuable ecosystem services associated with such an ecosystem.

Landscapes

Naturally, landscapes consist of a mosaic of many different patches that have been created by different processes. The size of natural patches affects the number, type and abundance of species they contain. At the periphery of patches, influences of neighbouring patches become apparent, known as the ‘edge effect’. In urban areas, patch edges are subjected to increased levels of heat, dust, desiccation, chemical or other pollution, human disturbance, invasion of exotic species and other factors. The depth, to which all these factors affect patch edges, depends on the physical structure of the patch vegetation. Edges seldom contain species that are rare, specialists or require larger tracts of undisturbed core habitat.

In natural systems, patch edges are curvilinear or lobed, a feature that promotes species movement across boundaries and thus species distribution and genetic exchange amongst populations and patches. Fragmentation due to urban development usually reduces core habitat and greatly extends edge habitat, which causes a shift in the species composition, which in turn puts great pressure on the dynamics and functionality of ecosystems. In addition, many patches in urban areas are rectilinear; these straight edges promote movement along boundaries only, contributing to the isolation of within-patch populations (Perlman & Milder 2005).

Lobed and elongated patches are more heterogeneous than compact round patches – this enables the protection of a greater genetic and species diversity and hence a better resistance to pests, diseases and environmental fluctuations – provided that negative edge effects can be kept out of the interior of such landscape patches. This has important implications for urban planning – to maximise 38

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ecosystem functioning and services, patch interiors need to be protected and shapes planned in such a manner as to reduce edge effects or spread the risk of extreme events. Thus the straightening or canalisation of rivers and filling up of wetlands greatly reduces the ability of such systems to absorb peak floods (Perlman & Milder 2005).

Corridors

These may be remnant patches of landscapes or, in natural systems, continuous tracts of specific habitats that connect similar habitat patches. The presence of corridors can increase population viability and ecosystem function by acting as conduit for movement. However, corridors are dominated by edge species and are less effective for the protection of rare or keystone species. The functionality of corridors for biodiversity depends greatly on the corridor width, connectivity and heterogeneity. Riparian zones, including the vegetated but normally dry floodplains, are some of the most important corridors that should be retained and protected during development.

Overall, to maintain at least some ecosystem services within the urban environment, it is important to protect a mixture of large natural patterns, vegetated riparian corridors and natural remnants within urban areas, and, as far as possible, ensure effective connectivity between larger patches (Perlman & Milder 2005).

How does urban expansion affect biodiversity?

Loss of native habitat through land clearing, grading, buildings and infrastructure

Throughout history, humans have settled in areas where ecosystem services are the highest. Many cities have thus evolved on fertile lowlands or along aquatic and coastal systems. The more the physical substrate of an ecosystem is altered, the less reversible the change. It is not only the area of cities that infringes on native habitat, but also sites where building materials are sourced or excavated as well as sites where waste is accumulated (Perlman & Milder 2005).

Habitat fragmentation

Urban areas and transport systems either perforate or divide native habitats and populations into discontinuous entities. All species have different requirements for maintaining viable populations – number of individuals, size, shape and/or area of the occupied patch, nature and quality of the habitat, genetic variation within the population, available migration routes as well as interactions with other species. Small populations may become self-incompatible or undergo genetic depression, leading to the gradual extinction due to fragmentation. This may only become evident many years after the actual fragmentation has occurred, and is referred to as the ‘extinction debt’. Only few generalist species are able to adapt to the human environment – these may proliferate, but overall the diversity of species in urban environments diminishes.

Perforation happens during exurban development, where scattered houses are built within natural habitat (Perlman & Milder 2005). The currently fashionable trend to ‘escape’ the city in eco- or agriestates rapidly increases the amount of edge effect and related disturbances through access routes, greatly reduces core habitat and has been shown in America to have a far greater detrimental effect on species diversity than clustered housing developments (Maestas et al. 2003). Similar studies are urgently required in the southern African context to provide adequate guidelines for future developments.

Human corridors, mostly roads, apart from transforming large tracts of land, act as filter or barriers to the movement and dispersal of many native species, whilst facilitating the spread of invasives.

Roads can seriously affect amphibians and reptiles if the former are situated between different types of habitats that these species use during different phases of their life cycle. Further ecological costs of roads are altered drainage patterns and increased runoff, which in turn contributes to increased erosion and pollution. the green building HANDBOOK

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Introduction of exotic species

Exotic species, due to the absence of predators, have a competitive advantage over native species, enabling them to gradually out-compete and displace native species. However, the ‘new’ species seldom have the same ecological functions within the ecosystem as the original species, and with their different dynamics further alter the functioning of the ecosystem (Perlman & Milder 2005).

Locally, large tracts of land have already been rendered unproductive due to the invasion of Lantana, pompon weed, or wattle to name a few.

Domestic cats and dogs potentially become new predators, but do not hunt the same prey as the displaced predators. Some natural predators may proliferate because they are able to switch to alternative food sources – baboons are a good example. The ‘original’ prey can now become a pest – these are most commonly rodents, birds and insects. Many of the larger mammals are hosts of parasites or diseases that greatly affect humans as well. Lyme disease is on the increase due to rising deer populations in America (Perlman & Milder 2005); the incidence of tick fever is on the rise in southern Africa –ticks being distributed by rats and birds.

Habitat degradation due to air pollution

By far the largest impact of urbanisation is caused by increasing amounts of CO2 emitted from fossil fuel combustion to meet the energy demands of buildings, industry and transport.

Higher levels of CO2 and other greenhouse gasses absorb and change the energy budget of the upper atmosphere. This results in more extreme climatic events – more intense storms, temperature extremes, changing rainfall patterns, and around cities affects general surface air temperatures. This heat-island effect has been recorded around most major cities, where the microclimate is sufficiently different from surrounding areas that native species are no longer adapted to survive there or significantly change their breeding and/or growth patterns.

Changing rainfall patterns reduces rainfall effectivity, increases erosion, changes the duration of growing seasons for plants and hence has a major impact on biomass productivity, including grazing and crop production.

One of the most troubling effects of changing CO2 levels is the impact on plant physiology – plants convert CO2 to various high-energy forms of carbon (sugars, carbohydrates), and produce O2 as a by-product. Different plant species do so via different metabolic pathways: For C3 plants, low CO2 is suboptimal. Rising CO2 levels thus act as a fertilizer, adding to the competitive advantage of these plants. Most of the local grasses – the backbone of livestock production in southern Africa - are C4 species, whilst trees, woody shrubs and the majority of alien invasives are C3 species. Bush encroachment, as well as exotic plant invasion is thus greatly enhanced by rising CO2 levels (Körner 2003). This does not only change community structure and species composition, but also affects interactions between plants and animals, such as pollination (indispensable for crop production) and grazing capacity, and – together with climate extremes, dynamics in natural disturbances such as fire.

Recent and more frequent devastating fires in Russia, Greece and California are examples.

Changes to ecological communities due to land and water pollution

Another significant impact is caused by nutrient loading of ecosystems, both terrestrial as well as aquatic. The most common nutrients are nitrogen and phosphorous, which originate from landfills, polluted storm water and sewage that spills directly into aquatic systems during heavy rainfall events, road runoffs, industry, detergents as well as fertilizers applied to and leached from gardens and sport fields (Perlman & Milder 2005).

Populations are controlled by competition with other species for limiting resources. Examples of such resources are specific nutrients, sunlight, food sources or space for growth. Should a normally limiting the green building HANDBOOK

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PROFILE

Breaking the mold Designed using sustainable materials, with a contribution from BASF, the Lofthome is affordable, beautiful – and as Lofthome architect Robert van Kats explains, it is proving very popular.

If sustainable construction demands a new way of thinking and working, the creators of Lofthome share BASF’s pioneering spirit. A Lofthome is a residential home that is both affordable and energy efficient.

Available in the Netherlands and, most recently, Belgium, each Lofthome is built to order, with scope for the client to choose their own layout. The team behind Lofthome has broken the mold – both in terms of its design and its conception. “In the Netherlands, the traditional process is that the architect comes up with the design, you find a contractor, and the house gets built,” explains Robert van Kats, Architect Director of Blok Kats van Veen architects, and co-creator of Lofthome. “But Lofthome is the result of a collaboration of the architects, a city marketer and the contractor.”

A collaborative approach

This collaborative approach has allowed Lofthome’s creators to make the entire construction process more efficient. The structure of the home is engineered off-site, reducing the actual construction phase to just two months. “That in itself is a form of sustainability as the process is so short,” says van Kats.

The Lofthome team also worked together to identify the most sustainable materials. Among these was BASF’s Elastopir®, a polyurethane foam used in the sandwich panels that make up the facade of each Lofthome. BASF developed this durable, fireresistant foam to offer the highest level of insulation possible – a major factor in developing low-energy buildings. In the case of The steel and glass construction is a refreshing departure Lofthome, the insulation level is almost double that required by from the brickwork of more traditional homes in the current Dutch building regulations. The design also includes heat Netherlands. recovery ventilation units, solar water heaters, triple glass walls, and other sustainable features – and every material used can be recycled.

A marriage of sustainability and design

This marriage of sustainability with design aesthetic is important for van Kats and his team: “For us, sustainability is an integral aspect of design. There’s no compromising.”

It is an approach that many argue needs to be more widely adopted, and van Kats agrees: “I believe our professional field can contribute to a sustainable future in terms of constructing cities – but we need a lot of steps. If you arrange a good team of people [that includes] organizations and government, which really sets out a vision and a goal to have a low-energy-use city, you’ve already achieved a lot. Then you can start working on the future.”

For us, sustainability is an integral aspect of design. There’s no compromising.

Contact Us:

BASF Holdings South Africa (Pty) Ltd. Petra Bezuidenhout Head of Communications E-mail:petra.bezuidenhout@basf.com www.basf.co.za

BASF.indd 2

The Lofthome’s versatile design gives clients the freedom to create their own layout.

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chapter 2: Ecology and the built environment

resource be added in large amounts, the species composition and thus functioning of the community will change significantly.

Excessive nutrient loading in aquatic systems is referred to as ‘eutrophication’. In such systems, weeds such as the water hyacinth – a common problem in local inland waters - and algae will proliferate.

These are not long-lived; the increased dead matter is being decomposed by bacteria that can form massive blooms and then rapidly consume all dissolved oxygen in the water, killing off other organisms living in the water.

Hydrological cycle

Urban areas, no matter how they have been developed, remain part of a larger watershed, where water is collected after precipitation and channelled via streams to eventually reach the oceans. In natural systems, dense vegetation on the landscapes protects watersheds by stabilising slopes, absorbing precipitation, further slowing down water runoff and thus increasing infiltration into groundwater reserves (Figure 1). This minimises erosion and sedimentation of streams and dams, while water that does reach the streams is purified either by vegetation or the topsoils through which it is filtered, and excessive flooding is greatly prevented. Wetlands that develop in depressions help further to absorb peak floods after intense rain showers, while marsh plants have a high capacity for recycling organic wastes washed off from surrounding landscapes and purifying water (Hough 2004).

Figure 2.1: Comparison of the hydrological cycle in natural and urban systems, as adapted from Hugo & de Villiers (1995)

Clearing vegetation for development significantly increases the volume and speed of stream flow after rainfall events, even higher runoff volumes accrue after surfaces have been sealed by impervious surfaces such as rooftops, paving and large tarred areas. This altered process washes pollution straight into water bodies without any filtering, as increased storm water runoff overburdens sewer systems and treatment plants.

As wetlands are unsuitable for construction, past generations sadly regarded them as wastelands.

Accordingly, they were drained or used as landfill sites. In fact, many of the oldest mine dumps in Gauteng are on wetlands. The destruction of wetlands and reduction of floodplains around rivers, as well as canalisation and straightening of rivers has, together with the effects of sealed and denuded surfaces, led to increased incidences of devastating floods in urban areas after intense rainfalls.

Conclusion

Ecosystems are open and dynamic, not static and controllable by man. They are shaped by regular as well as unpredictable disturbances, but if they are intact and fully functional, can maintain their functioning at several successional stages throughout their recovery from disturbances. Nature should thus not be seen as impeding development, but rather, urban development should be designed with natural systems in mind. If so, ecosystems should be able to maintain their key functions and man in the urban environment will continue to benefit from ‘urban’ nature. the green building HANDBOOK

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However, to enable planners to create the environmentally most favourable developments, urban ecosystems still need more rigorous investigation to fully understand the interactions between socioeconomic and biophysical factors and their feedback mechanisms. A comparative analysis of natural and urbanised ecosystems should indicate accommodating design principles or predictability on potential impacts as a gauge to measure such probability. More information is necessary not only on how ecosystems function and how this function can be maximised in the urban landscape, but also on how such function or deterioration can be verified, measured and monitored to enable better planning in the future and facilitate much-needed restoration of urban ecosystem function.

References

Alberti, M. 2005. The effects of urban patterns on ecosystem function. International Regional Science Review, 28, 168-192.

Costanza, R., D’Arge, R., de Groot, R., Farber, S., Grasso, M., Hannon, B., Limburg, K., Naeem, S., O’Neill, R. V., Paruelo, J., Raskin, R. G., Sutton, P. and van den Belt, M. 1998. The value of the world’s ecosystem services and natural capital. Ecological Economics, 25, 3-15.

Hough, M. 2004. Cities and natural processes. Routledge, New York.

Hugo, L. and de Villiers, B. 1995. Riverine green belts are invaluable urban assets. Muniviro, 12(1):17-19.

Kibert, C.J., Sendzimir, J., and Guy, B. 2000. Construction ecology and metabolism: natural system analogues for a sustainable built environment. Construction Management and Economics, 18, 903-916.

Körner, C. 2003. Ecological impacts of atmospheric CO2 enrichment on terrestrial ecosystems. Philosophical Transactions: Mathematical, Physical and Engineering Sciences, 361, 2023-2041.

Maestas, J. D., Knight, R. L. and Gilgert, W. C. 2003. Biodiversity across a rural land-use gradient. Conservation Biology, 17, 1425-1434.

Perlman, D.L., and Milder, J.C. 2005. Practical ecology for planners, developers and citizens. Island Press, Washington.

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chapter 3: Landscape Architecture – Ecological Conciousness

Landscape Architecture – Ecological Conciousness Graham A. Young Senior Lecturer, Department of Architecture University of Pretoria Principal, Newtown Landscape Architects cc

Introduction

If we are to create a sustainable world – one in which we are accountable to the needs of all future generations and all living creatures – we must recognize that our present forms of agriculture, architecture, engineering, and technology are deeply flawed. To create a sustainable world, we must transform these practices. We must infuse the design of products, buildings and landscapes with a rich and detailed understanding of ecology.1 Landscape architect, Ian McHarg discusses survival on earth and how we should plan and design for “better fitting” environments. To illustrate his point he relates the story of an astronaut in his capsule.

“An aquarium lines the walls of the capsule, containing algae and decomposers. It is a closed system and works like this. Sunlight falls upon the algae, which use carbon dioxide, water, air, and light to fix carbon, and then expel oxygen. The astronaut breathes air, consumes oxygen, and exhales carbon dioxide, which the algae absorb. Thus, there is a closed cycle of oxygen and carbon dioxide. The astronaut drinks, then pees into the aquarium; water condenses on the outside and is collected by the astronaut - a closed cycle of water. The astronaut hungers, he collects some algae and eats. In due time he defecates into the medium where live the decomposers that reduce the waste into nutrients employed by algae, which grow, and which the astronaut eats. Here is a closed cycle of food. There is one input-light; one export - heat. Oxygen, carbon dioxide, water, food, wastes, and nutrients go ‘round and ‘round”. 2 This is a simple model, but all the essentials are there for a perfect fit. This is the way nature works; each part has its place and contributes to the health of the whole. “Surely it is better to understand the natural processes, and act accordingly”, McHarg contends, “than to subjugate nature”. 3 He argues for a search for fit environments and refers to Lawrence J. Henderson’s assertion that there is a necessity for all organisms to find the fittest available environment, adapt it and the self to accomplish better fitting. If we assume that sustainability incorporates the survival of the human race, we can be confident that both present and future generations will need the vital life support functions of a healthy environment. These functions are called ‘critical natural capital’, and they cannot be substituted by human capital. So if we are to achieve a better fit, we must first be sure that the resource consumption and waste generation associated with patterns of urban development do not threaten critical natural capital because current patterns are clearly not sustainable.4 Ecological design is a way to understand how to achieve ‘a better fit’.

Ecological Consciousness

According to Van der Ryn and Cowan5, ecological design embraces conservation, regeneration and stewardship alike. Ecological design occurs in the context of specific places. It grows out of place and responds to the particularities of place: the soils, vegetation, climate, topography and the availability of water. It seeks locally adapted solutions that can replace matter, energy, and waste with design intelligence. Such an approach matches biological diversity and cultural diversity rather than the green building HANDBOOK

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compromising both the way conventional design solutions do. Ecological design brings the natural flows to the foreground. It celebrates the flow of water on the landscape, the fertility of the earth and the beauty of vegetation. It renders the invisible visible. Ultimately, ecological design deepens our sense of place. Ecological design is a way of integrating human purpose with nature’s own flows, cycles and patterns. It begins with the richest possible understanding of the ecological context of a given design problem and develops solutions that are consistent with the cultural context. Ecological designers are facilitators and catalysts in the cultural processes underlying sustainability and take a systems approach to design. Systems design is an exceptionally trans-disciplinary process and landscape architecture is one of the disciplines that have a key role to play in the design of our built environment.

Figure 3.1: Vision for an ‘Eco Park’ in Johannesburg’s inner city (Newtown Landscape Architects)

Landscape Architecture

When asked where landscape architects work, “many people might point out their back door to the garden. It would be more accurate, however, to look out the front door. The landscape is anywhere and everywhere outdoors, and landscape architects are shaping the face of the Earth across cities, towns, and countryside alike. Landscape architecture involves shaping and managing the physical world and the natural systems that we inhabit. Landscape architects do design gardens, but what is critical is that the garden, or any other space, is seen in context. All living things are interdependent and the landscape is where they all come together. Context is social, cultural, environmental and historical, amongst other considerations. Landscape architects are constantly zooming in and out from the details to the big picture to ensure that balance is maintained.”6 Landscape architecture operates at the interface of art and science. The art provides a vision for a landscape and the science includes an understanding of the social and natural systems, including geology, soils, plants, topography, hydrology, climate and ecology. “The [landscape architects] challenge is to awaken the rich potential that resides within this overlap of disciplines through a reinvigoration of the connection between beauty and the environment … such that our landscapes can be beautiful and sustainable”. 7 Because landscape architects design the setting for the built environment it’s not unsurprising then, that a new consciousness has crept into the design of landscapes - an awareness of the fragile environment and sensitivity to the natural environment and its ecological limits. No longer can landscapes be made in a void, but rather they must relate and respond to their surroundings.

Sustainable landscape design therefore requires holistic, ecologically based strategies to create landscapes that do not alter or impair but instead help repair and restore existing site conditions. Site systems such as plant communities, soils, and hydrology must be respected as patterns and processes of the living world. These strategies apply to all landscapes, no matter how small or how urban.

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Figure 3.2: Indigenous planting design at //hapo, Freedom Park (NBMG Landscape Architects)

This new consciousness suggests an approach that is somewhat different from conventional design. Birkland suggests that “what is required is a move from traditional ‘remedial’ approaches to preventative ‘systems design’ solutions that restore the ecology, foster human health and prioritise universal well-being over private wealth accumulation. Designers in all fields and walks of life have a crucial role to play in this transformation. It is now possible to design products, buildings, and landscapes that purify the air and water, generate electricity, treat sewage and produce food. Instead of applying generalised analyses, goals, criteria, techniques and indicators to any situation (as did ‘modernism’ in architecture) the design of appropriate case-specific, problem solving tools should form a fundamental part of the design process.” 8

Ecological Design

Useful in understanding sustainable ecologically-based landscape design are the “Valdez Principles for Site Design,” developed by Andropogon Associates. 9 These strategies are especially important to correctly integrate the built environment into its setting (the landscape).

• Recognition of Context. No site can be understood and evaluated without looking outward to the site context. Before planning and designing a project, fundamental questions must be asked in light of its impact on the larger community.

• Treatment of Landscapes as Interdependent and Interconnected. Conventional development often increases fragmentation of the landscape. The small remaining islands of natural landscape are typically surrounded by a fabric of development that diminishes their ability to support a variety of plant communities and habitats. This situation must be reversed. Larger whole systems must be created by reconnecting fragmented landscapes and establishing contiguous networks with other natural systems both within a site and beyond its boundaries.

• Integration of the Native Landscape with Development. Even the most developed landscapes, where every trace of nature seems to have been obliterated, are not self-contained. These areas should be redesigned to support some component of the natural landscape to provide critical connections to adjacent habitats.

• Promotion of Biodiversity. The environment is experiencing extinction of both plant and animal species. Sustaining even a fraction of the diversity known today will be very difficult. Development itself affords a tremendous opportunity to emphasize the establishment of biodiversity on a site.

Site design must be directed to protect local plant and animal communities, and new landscape plantings must deliberately re-establish diverse natural habitats in organic patterns that reflect the processes of the site.

• Reuse of Already Disturbed Areas. Despite the declining availability of relatively unspoiled land and the wasteful way sites are conventionally developed, existing built areas are being abandoned and new development located on remaining rural and natural areas. This cycle must be reversed.

Previously disturbed areas must be re-inhabited and restored, especially urban landscapes. the green building HANDBOOK

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• Making a Habit of Restoration. Where the landscape fabric is damaged, it must be repaired and/or restored. As most of the ecosystems are increasingly disturbed, every development project should have a restoration component. When site disturbance is uncontrolled, ecological deterioration accelerates, and natural systems diminish in diversity and complexity. Effective restoration requires recognition of the interdependence of all site factors and must include repair of all site systems soil, water, vegetation, and wildlife.

The above strategies serve as guidelines in landscape design and challenge the design for appropriate development. Emerging from these strategies are site-adaptive considerations, which are critical to achieving sustainable landscape design.

10 Natural Characteristics. The greatest challenge in achieving sustainable landscape design is to realize that much can be learned from nature. When nature is incorporated into designs, spaces can be more comfortable, interesting, efficient and beautiful. It is important to understand natural systems and the way they interrelate in order to work within these constraints with the least amount of environmental impact. Like nature, design should not be static but always evolving and adapting to interact more intimately with its surroundings.

• Wind – The major advantage of wind in landscape development is its cooling aspect. For example, trade winds in our sub-tropical environments often come from the northeast to the southeast quadrant, orientation of structures, and outdoor gathering places to take advantage of this cooling wind movement, or “natural” air conditioning. Native cultures understand this technique quite well, and local structures reflect these principles. Of course the other consideration is to ensure that structures or outdoor gathering spaces are protected from cold and / or strong prevailing winds.

• Sun – Where sun is abundant, it is imperative to provide shade for human comfort and safety in activity areas (e.g. pathways, patios). The most economical and practical way is to use natural vegetation, slope aspects, or introduced shade structures.

• Rainfall – Many settings must import water, which substantially increases energy use and operating costs, and makes conservation of water important. Rainfall should be captured for a variety of uses (e.g., drinking, bathing, irrigation) and this water reused for secondary purposes (e.g., flushing toilets, washing clothes). Stormwater or excess runoff from developed areas should be channelled and discharged in ways that allow for groundwater recharge instead of soil erosion. Minimizing disturbance to soils and vegetation and keeping development away from natural drainage ways protects the environment as well as structures within it.

• Topography – Slopes do not have to be an insurmountable site constraint if innovative design solutions and sound construction techniques are applied. Topography can potentially provide vertical separation and more privacy for individual structures. Changes in topography can also enhance and vary the way a visitor experiences the site by changing intimacy or familiarity. Again, protection of soil and vegetation are critical concerns in high slope areas, and elevated walkways and point footings for structures are appropriate design solutions to this problem.

• Geology and Soils – Designing with geologic features such as rock outcrops can enhance the sense of place. For example, integrating rocks into the design of a deck or boardwalk brings the visitor in direct contact with the resource and the uniqueness of a place. Soil disturbances should be kept to a minimum to avoid erosion of fragile t soils and discourage growth of exotic plants.

If limited soil disturbance must take place, a continuous cover over disturbed soils with erosion control netting should always be maintained.

• Aquatic Ecosystems – Development near aquatic areas must be based on an extensive understanding of sensitive resources and processes. In most cases, development should be set back from the aquatic zone and protective measures taken to address indirect environmental impacts. Particularly sensitive habitats such as beaches should be identified and protected from any disturbance.

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chapter 3: LANDSCAPE ARCHITECTURE_ECOLOGICAL CONSCIOUSNESS

• Vegetation – Exotic plant materials, while possibly interesting and beautiful, are not amenable to maintaining healthy indigenous ecosystems. Sensitive indigenous plant species need to be identified and protected. Existing vegetation should be maintained to encourage biodiversity and to protect the nutrients held in the biomass of indigenous vegetation. Indigenous planting should be incorporated into all new developments. Vegetation can enhance privacy, be used to create “natural rooms,” and be a primary source of shade. Plants also contribute to the visual integrity or natural fit of a new development in a natural setting. In some cases, plants can provide opportunities for food production and other useful products on a sustainable basis.

• Wildlife – Sensitive habitat areas should always be avoided. Encouraging wildlife to remain in the area. This can be achieved by maintaining as much original habitat as possible.

• Visual Character – Natural vistas should be used in design whenever possible. Open up the design to take advantage of beautify vistas and to screen visual intrusions.

Cultural Context. Local archaeology, history, and people are the existing matrix into which designed public landscapes must fit. Sustainable principles seek balance between existing cultural patterns with new development. Developing an understanding of local culture and seeking their input in the development processes can make the difference between acceptance and failure.

• Archaeology - A complete archaeological survey prior to development is imperative to preserving resources. Once resources are located, they can be incorporated into designs as an educational or interpretive tool. If discovered during construction activities, work should be stopped and the site re-evaluated. Sacred sites must be respected and protected.

• History - Cultural history should be reinforced through design by investigating and then interpreting vernacular design vocabulary. Where appropriate local design elements and architectural character should be analysed and employed to establish an architectural theme for new development.

• Indigenous Living Cultures - Cultural traditions should be encouraged and nurtured. A forum should be provided for local foods, music, art and crafts, lifestyles, dress, and architecture, as well as a means to supplement local incomes (if acceptable). Traditional harvesting of resource products should be permitted to reinforce the value of maintaining the resource.

Conclusion

Increased ecological knowledge is at the core of sustainable landscape design. When taking an ecological approach to landscape design, components defer to the character of the landscape they occupy so that the experience of the landscape will be paramount and restoration of the land can take place. Instead of only human functional needs driving the design, site components respond to the spatial character, climate, topography, soils, and vegetation as well as the existing cultural context, to achieve “places that are less intrusive yet more rewarding, less fashionable yet more enduring”11 … and they are beautiful and sustainable!

However, a word of caution is needed when we consider the notion of ‘sustainability’. The word has been on just about everyone’s lips – including corporate lips – and this should signal a warning.

The concept has “achieved a degree of meaninglessness, with LEED certification [or any of the new rating systems] today anointed as the only worthy design criterion. I am troubled”, Treib continues, “By any design addressed to a single goal or parameter (including purely aesthetic acts removed from functional or social purpose). Might not a better approach be to adopt the adverb ‘sustainably’ to describe how we should design, rather than posing the noun ‘sustainability’ as a single goal? Or, to put it a different way, to use an ecological consciousness to guide the way we design for a greater purpose? “12 Sadly, we often stop at the level of indigenous planting, green roof or wetland design, rather than considering these ‘living systems’ as a means for achieving an aesthetic level beyond the merely functional or ‘sustainable’. “ The photographer Edward Weston once wrote that one should photograph the green building HANDBOOK

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a thing ‘not for what it is, but for what else it is’. Achieving that ‘what else’ is what makes landscape design an art. Without such aspirations, we operate only at the level of environmental plumbing.

Plumbers are needed of course, but so too are artists. Rather than considering the situation as an either/or, I prefer to think of it as a both/and, with the ultimate goal being to elevate pragmatics to the level of poetics.” 13 On 10 September 1990, Ian McHarg received the National Medal of Art from President Bush. Included in Bush’s remarks was, according to McHarg “an astonishing and totally unexpected statement: ‘Let us hope that in the next century the finest accomplishment of art will be the restoration of the land.’

The ecological view and the skills of landscape architecture and ecological planning must contribute leadership for this restoration – it is, indeed, a quest for life.” 14

References

1 Van der Ryn, S. and Cowan, 1996. S. Ecological Design. Island Press, Washington, D.C. 2 McHarg, I. 1996. A Quest for Life, John Wiley and Sons Inc., New York. pp 242.

3 McHarg, I. 1996. A Quest for Life, John Wiley and Sons Inc., New York. pp 248.

4 Owens, S: ‘Can land use planning produce the ecological city?’Town and Country Planning, 1994, Vol. 63 No. 6, pp170-173.

5 Van der Ryn, S. and Cowan, 1996. S. Ecological Design. Island Press, Washington, D.C. 6 Waterman, T. 2009. The Fudementals of Landscape Architecture. AVA Publishing, Lausanne, Switzerland. pp 8.

7 Kate Cullity in: Richardson, T. 2011. Futurescapes. Thames and Hudson, London. pp11.

8 Birkeland, J. 2002. Design for Sustainability. Earthscan Publications Ltd. London. pp 1 - 2.

9 United States Department of the Interior, 1993. Guiding Principles of Sustainable Design, U.S. Government Printing Office. pp 41.

10 United States Department of the Interior, 1993. Guiding Principles of Sustainable Design, U.S. Government Printing Office. pp 48 - 50.

11 Marc Treib in: Richardson, T. 2011. Futurescapes. 1ST ed. Thames & Hudson, London. pp15.

12 Marc Treib in: Richardson, T. 2011. Futurescapes. 1ST ed. Thames & Hudson, London. pp13.

13 Marc Treib in: Richardson, T. 2011. Futurescapes. 1ST ed. Thames & Hudson, London. pp14.

14 McHarg, I. 1996. A Quest for Life, John Wiley and Sons Inc., New York. pp 375.

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BLUESCOPE STEEL BlueScope Steel Southern Africa markets coated steel materials within the Sub-Saharan African region. The products are sold to roll formers and roofing system suppliers, who manufacture high quality steel roofing or cladding systems for the market.

Developed to withstand tough climatic and aggressive environmental conditions such as found in the region, the products ZINCALUME® steel, Clean COLORBOND™ steel and Clean COLORBOND™ ULTRA steel have experienced excellent acceptance by domestic markets. The BlueScope Steel extensive warranty provides peace of mind to project managers, architects and property owners who register prior to commencement of works.

SUSTAINABLE ROOFING MEANS GREEN OUTCOMES BlueScope Steel believes that South Africa can ill-afford the ongoing cost of maintaining and replacing roofs that should give many years of service, provided materials used meet architects and manufacturers’ standards.

We urge developers to monitor what is happening on site to ensure that materials used are the same as those that are specified.

In the company’s opinion, many South African property owners are not getting the fairest deal for their Rands when roofs are fitted to new developments or replaced during renovation work on buildings.

According to the company, there is a concerning lack of knowledge and information among many contractors and roofing system suppliers as to the effectiveness of the various types of steel roofing materials, resulting in great deal of non-compliance with minimal design standards.

For example, along the South African coastline, steel roofing often fails after just 5 years due to the Z160 and Z200 coating mass of galvanised or pre-painted galvanised steel being used. Architects and customers should be aware of being supplied cheaper low coating mass products (Galvanised Z160 or Z200 or Aluminum / Zinc AZ100) in a market where corrosion is a serious issue up to 5 km from the coast line.

According to the company’s Wayne Miller, this practice does not support the ethos of sustainable building, and is highly prejudicial to consumer rights. Sadly this has gone by largely unchallenged. “With the worldwide swing to sustainable building practices, roofing systems should provide the owner with optimum levels of performance and lifespan.

Reputable suppliers would recommend a Galvanised Z275, or ZINCALUME® AZ150 to ensure building durability and performance through its life in this environment”, he says.

BlueScope Steel recommends using only premium metallic coated steel such as ZINCALUME® Steel or pre-painted grades such as Clean COLORBOND™ Steel, with an

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Aluminium/Zinc alloy coating (AZ150 coating) if building within 5 km – 400 m from the sea.

When building within 100 - 200 metres of the water, use Clean COLORBOND™ ULTRA Steel, with an AZ200 coating – coated to a mass of 200 g/m2 over the steel substrate. This is also applies to severe industrial environments - where there are aggressive fumes or particulate fallout within the 200 meter radius.

A high performance infrared paint system on Clean COLORBOND™ Steel incorporates various sustainability features such as: • high reflection of incoming solar radiation – meaning a cooler roof • exceptional colour retention • anti-chalking and anti-fungal • resistance to dirt staining The BlueScope Steel manufacturer’s warranty of performance is subject to terms and conditions and it is important that clients contact the BlueScope Steel office prior to installing. “Correctly used, our product should give a lifespan up to four times longer than the norm”, he says.

Identification of BlueScope Steel product is easy. Each panel of formed roofing material has been uniquely branded on the undersurface, thereby avoiding any confusion. Look for the brand.

CoMpANY CoNTACT DeTAilS: Wayne Miller, General Manager BlueScope Steel Southern Africa (Pty) Ltd Email: wayne.miller@bluescopesteel.com Tel: 021 442 5420 www.bluescopesteel.com

chapter 4: Maximising passive wind-driven ventilation: A case study

Maximising passive wind-driven ventilation: A case study Faatiema Salie Candidate Researcher Built Environment CSIR

Introduction

The American Society for Heating Refrigeration and Air-conditioning Engineers (ASHRAE) defines ventilation as the process of supplying air to, and removing air from, a space to control air contaminant levels, humidity or temperature within that space (ASHRAE, 2007). Ventilation may be mechanical, i.e. machinery is used as a driving force to; natural, which relies on natural forces such as wind and buoyancy to drive the airflow; or hybrid ventilation, which is a combination of natural and mechanical ventilation.

Passive wind-driven ventilation refers to natural ventilation which uses devices which have no moving parts and use wind-induced effects to drive ventilation (Khan et al, 2008). Examples of passive devices include windows, doors, atria and courtyards and chimney and exhaust cowls (Khan et al, 2008).

This chapter presents a case study performed at the CSIR Built Environment Test Site in Pretoria, which investigates the ventilation flow rates achieved in passive wind-driven ventilation in a typical South African low-income house. The passive devices investigated in this case study are windows and doors.

This chapter also presents the methodology for practically measuring ventilation flow rates in natural ventilation setting.

Methodology

Test area – South African low-income house

The low-income house used in this case study is situated on the CSIR Built Environment Test Site in Pretoria. A layout of the low-income house is shown Figure 1. This house has a floor area of 39.6m2, and a volume of 110.5m3. It has two bedrooms, a living room, kitchen and a bathroom.

Figure 4.1: Layout and window and door schedules of a typical South African low-income house the green building HANDBOOK

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Windows are located on the northern and southern facades, and doors on the southern and western facades. The openable window area on the northern façade is 1.92m2, and 1.62m2 on the southern façade. Openable window area is an important parameter because it is directly related to the amount of air which can enter and leave the house. The northern and southern facades are 2.5m high. The eastern and western elevations have been inclined at 11˚, and peaks at the centre at a height of 3.08m.

The thermal performance of this low-income house has been studied by Osburn (Osburn, 2010).

Using EnergyPlus (v 3.0.0.028) Osburn was able to establish the temperature profiles inside the house as a function of outside temperature, in extreme weather conditions. During summer months, most of the low-income houses in South Africa are not heated or cooled, and the internal temperature changes according to the outdoor temperature (Osburn, 2010). The model found that the inside temperature is always higher than the outside temperature, up to 12˚C higher in extreme summer conditions. This temperature differential was attributed to the galvanised roof sheeting.

Osburn recommended that windows and doors be left open to increase the air exchange rate, thereby reducing the internal temperature.

The test area of the low-income house is bedroom 2 only, i.e. the ventilation flow rate under different openable window areas is only measured in bedroom 2.

Measuring ventilation flow rates in the low-income house

In this case study, tracer gas (concentration decay) testing is used to determine the ventilation flow rate under different openable window areas. The tracer gas test performed follows the concentration decay method outlined in REHVA Ventilation Effectiveness Guidebook (REHVA, 2004). The tracer gas used in these experiments is Carbon Dioxide. The test is performed by releasing Carbon Dioxide in bedroom 2 and mixing it with the room air with a fan, as shown in Figure 2. Carbon Dioxide was released to a concentration of 5 000 ppm, or 0.5% of the volume of the room. The mixed air is allowed to stabilise, the ventilation strategy is employed, and the concentration decay is measured.

The concentration is recorded every two minutes at a single point in the room. This point is at the plan centre of the room at a height of 1.54m, which is the approximate average nose and mouth height of a South African adult. The concentration decay is measured using an infrared analyser.

Figure 4.2: Tracer gas testing equipment

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The directional wind speed and temperature are also measured on the CSIR Built Environment Test Site using a hot-wire anemometer with a directional probe, positioned perpendicular to the northern face of the low-income house.

For each different ventilation strategy, three tests are performed. One in the morning at about 9am, one at noon, and one in the afternoon at about 3PM. Data from these tests are in the form of Concentration VS Time plots, and can be converted to log-Concentration VS Time as shown in Figure 3. The data from these tests can be used to calculate the ventilation flow rate and the mean age of air (MAA) of the passive ventilation strategy.

Figure 4.3: Concentration decay curves of tracer decay testing

The ventilation flow rate is determined by the gradient of the log-Concentration VS Time graph.

This graph should be a straight line. The ventilation flow rate is given by Equation 1: ... Equation 1 Where: l is the ventilation flow rate c is the concentration t is the time The ventilation flow rate has units of air changes per minute. It is conventional to report ventilation flow rate in air changes per hour (ACH), and so the value calculated from the slope of the graph should be multiplied by 60 to get ACH. The MAA is the average time it takes a pocket of air in the room to be replenished by clean air.

The MAA of the room is calculated from the weighted area under the Concentration VS Time curve, and is given by Equation 2 (REHVA, 2004):

‌ Equation 2 the green building HANDBOOK

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Where: t is the mean age of air i is the counter n is the total number of measured points c is the concentration t is the time l is the decay or gradient of the linear part of the original Concentration-Time curve To this point, the test area and the way in which tests will be performed have been presented. The following section details the different passive ventilation strategies to be tested.

Passive ventilation strategies tested

In this case study, three ventilation strategies are presented, and illustrated in Figures 4.4 to 4.6.

Strategy 1 – All openings closed

Figure 4.4: Strategy 1 - All openings are closed

• All windows and doors of the low-income house are closed, as shown in Figure 4.4. • The exchange of air is due to infiltration and leakages.

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chapter 4: Maximising passive wind-driven ventilation: A case study

Strategy 2 – Cross-ventilation

Figure 4.5: Strategy 2 - Cross ventilation

• All of the windows of the low-income house are opened, as well as the door to bedroom 2, as shown in Figure 4.5.

• Maximum possible openable area to bedroom 2.

Strategy 3 – Single-sided ventilation

Figure 4.6: Strategy 3 - Single-sided ventilation

• All the windows of the house are closed, except for the window of bedroom 2. The door of bedroom 2 has also been closed. This is illustrated in Figure 4.6.

• Air will both enter and leave at the window of bedroom 2.

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It is important to note that the respective windows and doors of the respective ventilation strategy are only opened once the Carbon Dioxide mixture has stabilised in the room. The concentration decay is measured according to the ventilation strategy employed. The results of these tests are presented below.

Results

Ventilation flow rate

The ventilation flow rate of the morning, noon and afternoon tests of the three ventilation strategies are reported in Figure 4.7. These ventilation flow rates have been calculated from the log-Concentration VS Time graphs.

Figure 4.7: Ventilation flow rates for the different passive ventilation strategies

The average ventilation flow rate of Strategy 1, which is due to infiltration and leakages in the building envelope, was calculated to be 0.57 ACH. The average ventilation flow rate of Strategy 2 was calculated to be 16.9 ACH, and the average ventilation flow rate of Strategy 3 was calculated to be 8.1 ACH. In natural ventilation, the wind speed, and wind direction to a lesser extent, fluctuates constantly.

The variation in the number of air changes achieved in Strategies 2 and 3 could be attributed to attribute to these fluctuations. Strategy 1 is less affected by the wind effects compared to Strategies 2 and 3.

From these tests, it can be seen that by increasing the openable area to bedroom 2, an increase in ventilation flow rate is achieved.

MAA

The MAA is calculated from the weighted area under the Concentration VS Time graphs. In Strategy 1, the average MAA is calculated to be 98 minutes. This implies that it would take over one and a half hours to replenish the air in the bedroom 2 once.

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Figure 4.8: MAA for different ventilation strategies

The MAA of Strategy 2 is four minutes, and that of Strategy 3 is nine minutes. The MAA has an inverse relation to the ventilation flow rate. The slower the ventilation flow rate, the longer it takes for air to be replenished in the room. A comparison between Strategy 1 and 3 can be made by simply looking at Figure 8. The only difference between the ventilation strategy of Strategy 1 and 3 is the open window of Bedroom 2. This implies that by simply opening window of bedroom 2, the MAA was reduced by almost 90 minutes.

Conclusions

From these test results, the following conclusions can be made: • An increase in openable area resulted in an increase in ventilation flow rate.

• The ventilation flow rate is more dependent on the openable area than the wind speed and temperature.

• Which strategy performs best?

References

ASHRAE. Standard 62.1 of 2007 – Ventilation for acceptable indoor air quality. .

KHAN N, Yuehong S and Riffat B. A review on wind driven ventilation techniques. Energy and Builidngs Volume 8, pp 1586-1604. 2008.

OSBURN L. Energy efficiency of formal low-income housing within South Africa. Council for Scientific and Industrial Research. 2010.

REHVA Guidebook. Ventilation Effectiveness. Guidebook Number 2. 2004.

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chapter 5: Lessons for South Africa from global trends in environmental labelling of buildings and construction products

Lessons for South Africa from global trends in environmental labelling of buildings and construction products Naa Lamkai Ampofo-Anti Researcher Built Environment CSIR

Introduction

The consumption choices of individuals shape consumer markets and drive production patterns.

Environmental labelling serves as a means of communication, from the producer1, to the consumer2, of the consequences of consumption choices and behaviour so as to encourage the demand for, and the use of environmentally sound products3.

Encouraging the participation of all of mankind in environmental protection through appropriate access to product environmental information was endorsed by all three previous Earth Summits as indispensable to sustainable development. The Declaration of the United Nations Conference on the Human Environment (1972) points out that mankind’s efforts to defend and improve the human environment for the benefit of present and future generations will need to be founded on fuller knowledge of the environmental consequences of human actions4. To assist consumers to make environmentally sound purchasing decisions, Agenda 21 (1992) urges government, business and industry to develop consumer legislation and environmental labelling in consideration of the full life cycle environmental consequences of products and processes5. To accelerate the global shift towards sustainable consumption and production (SCP), the Johannesburg Plan of Implementation (2002) of the World Summit on Sustainable Development (WSSD) calls for a number of critical actions. These include the development of tools and policies founded on Life-Cycle Analysis; the development of public awareness-raising programmes on the importance of sustainable consumption and production (SCP); and the adoption, where appropriate, of voluntary, transparent, verifiable, non-misleading and non-discriminatory consumer information tools to provide information on SCP, in particular, the human health and safety aspects6.

This chapter examines the international state-of-the-art of environmental labelling of buildings and construction products7; and discusses ways in which the emerging South African framework for environmental labelling could benefit from the lessons learnt.

The role of Life Cycle Assessment in environmental labelling

The Life Cycle Assessment (LCA) concept, previously known as Life-Cycle Analysis, is a science-based tool which is used to measure the environmental performance of a product over its entire life cycle, from the acquisition of raw materials, through manufacture of the product, transportation and distribution, use and maintenance, and finally, to disposal of the product at the end-of-life (Figure 5.1).

Where the extent of the inquiry ends with transportation of the product to the point of disposal, it is 1 2 3 4 5 6 7

Industry and business Used broadly to denote government, organisations or the individual Used broadly, includes processes and services Paragraphs 6 and 7 Section I, Chapter 4: Changing consumption patterns, paragraphs 4.2-4.22 Chapter III: Changing unsustainable patterns of consumption and production, paragraphs 15(a), 15(c), 15(d) and 15(e) Construction products means all elements, materials and components which go into the construction of a building the green building HANDBOOK

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a cradle-to-grave analysis. If it includes the recycling potential, it is deemed a cradle-to-cradle analysis.

Environmental performance is measured in terms of a wide range of effect categories (Table 1).

1

2

Material extraction and processing

Material xxx manufacturing

3 On site construction or installation

PRE-USE PHASE

4 Use and maintenance

USE- PHASE

5 End- of- life

EOL

Figure 5.1: Generic life cycles stages of a construction product Figure 1: Generic life cycle stages of a construction product

Environmental labels and claims such as “recyclable” and “low energy” emerged in the 1980s in response to the growing global concern for environmental protection and conservation. To reduce confusion in the “green” market place, the International Organisation for Standardisation (ISO) developed its14020 series of standards, Environmental Labels and Declarations for which LCA is the main analysis method.

Of the three environmental labelling choices provided by the ISO 14020 series of standards, the Type III Environmental Product Declaration (EPD), which represents the closest link between LCA and environmental labelling, forms the basis for the building sector-specific EPD standard ISO 21930: 2007, Sustainability in building construction – environmental declaration of building products.

However, LCA is suitable for measuring the potential environmental effects of a product on the outdoor environment, but not the environmental risks associated with the use of that product in the indoor environment. Therefore, appropriate indoor air quality (IAQ) performance assessment standards are used in conjunction with the LCA-based standards when assessing the environmental performance of products destined for indoor use.

Building rating systems

First generation building rating systems

The environmental labelling of buildings contributes to society’s quest for sustainable development.

Starting with the United Kingdom’s (UK) Building Research Establishment Environmental Assessment Method (BREEAM), established in 1990, a large number of building environmental assessment and rating systems have been launched around the world to put the concept of Sustainable Construction which is “the creation and operation of a healthy built environment based on ecological principles and resource efficiency” (Kibert, 1994) into effective practice. They include but are not limited to HK BEAM (Hong Kong, 1995), Eco-Profile (Norway, 1996), LEED (USA, 1997), CASBEE (Japan, 2001), Green Star (Australia, 2002) and Green Star (South Africa, 2007).

Building environmental assessment and rating systems develop voluntary standards, linked to credits, against which the environmental performance of candidate buildings can be assessed. Typically, both indoor/outdoor environmental aspects are assessed. Summing the credits gives an overall score for the assessed building. The standards provide practical guidelines for improving the environmental quality of buildings relative to current typical building practices. The notion of rating8 is used together with the assessment as a logical outcome. For example BREEAM (UK) applies a rating scale ranging from “Excellent” to “Fair”.

Given the historical lack of an environmental-management structure in the construction industry sector, building rating systems have come to serve an important secondary function by providing a 8 Rating is used interchangeably with labelling

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framework that defines and guides the green building process (Blom, 2006; Cole, 1998; Zimmerman & Kibert, 2007). Building rating systems also foster a more integrated approach to design by the building team and provide a broad coverage of building-related environmental issues, enabling building performance to be comprehensively described.

However, “first generation” building environmental assessment and rating systems are subject to a number of shortcomings and limitations that constrain their future effectiveness as drivers for Sustainable Construction. To truly contribute to sustainable development, performance assessments would need to be expanded beyond environmental considerations to include the economic and social dimensions of sustainability. Even if the assessment is kept within the existing confines of environmental sustainability, performance would need to be assessed against the absolute impact or burden that a building system exerts on the environment (Cole, 1998). This would require quantification of all the complex links between decision-making in the building life cycle; and the resultant contribution to outdoor environmental problems such as climate change, or indoor environmental quality issues such as sick building syndrome (SBS). Environmental performance is however assessed indirectly, on the basis of proxies – “atmosphere”, “ecology” or “responsible sourcing of materials”. LCA studies have shown that the service life of the building and its components; and the end-of-life management are environmentally significant but these are generally overlooked in an assessment. Furthermore, given the shelter needs of the world’s ever growing population, the voluntary nature of building rating systems may not be sufficient to create the necessary critical mass of high performing buildings to meet the increasingly urgent national, regional and global sustainability targets.

Second generation building rating systems

Ultimately, building rating systems need a scientific basis that links sustainability principles with solutions appropriate for the building sector. Trends in the environmental labelling of buildings, which are highlighted in the following sections, suggest that the sector is has embarked on this new route to Sustainable Construction. The environmental assessment of buildings is becoming less prescriptive and more performance-oriented, where performance is defined in terms of assessment criteria derived from the actual, as opposed to the perceived, environmental effects of buildings.

International trends - Sustainable Building Alliance The Sustainable Building Alliance (SB Alliance) is an international coalition of standard setting organizations and construction industry sector stakeholders who aim to accelerate the international adoption of Sustainable Building (SB) practices through the promotion of shared methods of building performance assessment and rating (SBA, 2011). SB Alliance members include nine building assessment and rating tool developers, of which the most well-known are the US Green Building Council (LEED), the British Research Establishment (BREEAM).

Resources depletion

Primary energy

Water

Building Emissions Indoor Environment quality

Thermal comfort

Indoor air quality

Green house gas emissions

Waste production

Figure 2: Six Indicators of sustainability, adapted from SBA 2009 Figure 5.2: Six indicators of sustainability, adapted from SBA 2009

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In 2009, the SB Alliance identified a core set of six quantitative indicators for building performance assessments. Outdoor environmental effects will be assessed on the basis of four criteria, namely, primary energy, water, greenhouse gas emissions and waste. The assessment criteria for indoor environmental quality (IEQ), which reflect concerns for human health and well-being, are thermal comfort and indoor air quality (IAQ). The key source of information will be Environmental Product Declarations (EPDs) of building products. The additional indicators under discussion are economic performance, and visual and acoustic comfort. Unlike the first generation building rating systems which limit assessments to building design, construction and operation, the harmonised environmental assessment and rating methodology takes the entire building life cycle into consideration (SBA, 2009).

An assessment will factor in the service lives of building materials, components and elements; and will address deconstruction in lieu of demolition in the End-of-life (EOL) Phase. SB Alliance members started to implement the harmonised features by gradually phasing these into new versions of their building assessment and rating tools from 2009.

Regional trends – Harmonised European standard To prevent the plethora of national building rating systems from becoming a technical barrier to trade within the European Union (EU), the European Commission (EC) in 2004 mandated the European Committee for Standardisation (CEN) to develop harmonised, horizontal9 European Standards for the measurement of the embodied and operational environmental effects of whole buildings and construction products across the entire life cycle. The key concepts which inform the harmonised standards include but are not limited to (CEN, undated): • A holistic sustainability assessment which considers the economic, environmental and social performance of a building over the entire life cycle without value judgement; • Application of the principles of ISO 21930: 2007, Sustainability in building construction – environmental declaration of building products; and • A whole building assessment approach provided that a new building is assessed across all life cycle phases while the assessment of existing buildings is limited to the Use Phase and the EOL Phase.

• The standards are intended to be voluntary. However, when regulating, EU Member States are required to use European Standards and mandatory standards are becoming the norm rather than the exception in the European community.

National – International Green Construction Code (IgCC) By contrast to “green” building rating, which is voluntary and has spawned a niche market, the new International Green Construction Code (IgCC) is set to mainstream “green” building in the US as it stipulates enforceable minimum “green” requirements to be met by all buildings. The historic model code sets mandatory minimum requirements in respect of site development, materials use, energy and water efficiency, indoor air quality (IAQ) and commissioning (SB.com, 2011). A set of additional “project electives” gives users the option to customise content beyond the minimum sustainability requirements. As a model regulation, the IgCC requires adoption by a US state or jurisdiction to become law. Several local councils and state governments have already adopted the IgCC in the lead up to the release of the Final Version in March 2012. The IgCC was developed by the US International Code Council (ICC) in cooperation with a number of building sector stakeholders including the American Institute of Architects (AIA) and the US Green Building Council.

Building energy labelling

While all stages of the building life cycle demand energy and produce carbon emissions, the Use Phase (Figure 5.1) plays a dominant role, accounting for 40% of the world’s energy consumption, at least 20% of a country’s energy demand and 80-90% of a building’s life cycle energy demand. Building energy labelling provides a means to document, understand and reduce this dominant operating energy component and thereby contribute to security of energy supply and climate change mitigation efforts.

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chapter 5: Lessons for South Africa from global trends in environmental labelling of buildings and construction products

International – Common Carbon Metric for buildings The Common Carbon Metric (CCM) for buildings measures energy consumption and reports GHG emissions from the Use Phase of existing buildings. It is intended to support international, regional, national and local energy policy development and industry initiatives. While the developers do not present it as a building rating tool, the CCM for buildings gives the sector which represents 40% of the world’s energy consumption and associated 33% GHG emissions a tool and a protocol to measure, report and verify reductions in a consistent and comparable way (UNEP-SBCI, 2009). The actual reporting is done in carbon dioxide equivalents (kgCO2e) emitted per square metre per year in consideration of the building type and climatic region, but excluding the value-based interpretations inherent in weighting and benchmarking. The CCM methodology is consistent with that of a number of LCA-based standards, for example, the Greenhouse Gas (GHG) Protocol; ISO 15392: 2008 Sustainability in building construction and the ISO 14040 Series: Environmental Management – Life Cycle Assessment. The CCM for buildings was developed by the United Nations Environment Programme Sustainable Building and Climate Initiative (UNEP-SBCI) and unveiled at COP-15, Copenhagen 2010. It is currently undergoing two parallel processes, namely, pilot testing before it is released for use by the international community; and reconfiguration into an international standard so that it can form part of the ISO’s offering of standards for sustainability in buildings.

Regional – Energy Performance of Buildings Directive (EPBD) The Energy Performance of Buildings Directive (EPBD) is a key component of the energy efficiency policy of the EU, adopted to contribute to Europe’s Kyoto commitment, security of energy supply and competitiveness. The EPBD requires EU Member States to implement mandatory energy certification of all building types at the time of construction, sale or rent (EC, 2009). To support the implementation of the EPBD after it became law in 2003, the European Commission (EC) mandated CEN to develop standards covering the key energy demand aspects of the building Use Phase that is, heating, lighting, ventilation and thermal performance (CEN, 2011). The implementation of the Directive started in 2005 and as at 2009 the majority of EU Member States had certification schemes in place.

National – Building Energy Quotient Building Energy Quotient (bEQ) is an energy labelling programme which conveys information to consumers in a format similar to a nutritional label on food or the miles per gallon rating on a car (Reuters, 2009). The potential use of information provided by a bEQ label includes mandatory disclosure of building energy performance, an emerging policy already implemented in nine America States; and identification of the potential energy saving options for existing buildings. The bEQ rating system is applicable to both new and existing buildings including residential buildings higher than three storeys. It has two components, an Operational Rating (In Operation) and an Asset Rating (As Designed). Newly completed buildings receive an “As Designed” rating, based on simulation modelling results. An “In Operation” rating is awarded when a building has accumulated at least twelve consecutive months of actual energy use data. The “In Operation” rating is renewable annually therefore to maintain or achieve a preferred rating; building owners need to make use of the valuable insights provided by previous assessment data (Jarnagin, 2009). The bEQ labelling programme applies a 7-level technical scale10 to rate a building from A+ (Net Zero Energy) to F (Unsatisfactory). The results of an assessment are communicated in two ways – a prominently displayed label which confirms the building’s rating; and an energy certificate issued to the building owner. The bEQ labelling programme is an initiative of the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE). The bEQ label aims to drive both existing and new buildings towards net zero energy building11 (NZEB). Development of the two bEQ labels started in June 2009 and both were subsequently tested and refined through pilot projects.

10 Technical scale means a rating scale which uses a potential as opposed to an existing building as its reference point. (The rating scale of the prominent building rating systems discussed in previous sections is a statistical scale, that is, the benchmark is the existing building stock).

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Construction product certification programmes

Context for construction product certification

The outdoor and indoor environmental effect of a building is the sum total of the environmental effects of the hundreds of construction products – structural, envelope and finishing materials; and building services components – that go into the assembly and maintenance of the building. Product certification aims to avoid or reduce these potential effects at the level of individual construction products and is therefore an essential component of sustainable construction.

The outdoor environmental effects arise from resource use and pollutant release which may occur at any stage from raw material extraction to disposal or reuse of the construction product (Figure 5.1).

The environmental areas of protection (AoPs) of interest to society are ecological and human health, natural resources and the built environment. The effects may occur at a global, regional or local scale.

For example, GHG emissions contribute to climate change which is a global environmental problem.

By contrast, product labels such as “No VOC” or “low VOC” is to communicate compliance with Volatile Organic Compounds (VOCs) content regulations which seek to reduce the contribution of this class of chemicals to ground level ozone formation which is a local environmental problem. Since not all VOCs contribute to ambient air quality problems, “No VOC” or “low VOC” labelled products can still off-gas potentially toxic chemicals into the indoor environment (AQS, 2010).

Table 5.1: Environmental areas of protection and labelling criteria

Examples of outdoor environmental effects of concern

Examples of common indoor air contaminants of concern

Climate change Eutrophication Solid waste generation Fossil fuel (energy) depletion Fresh water intake

Formaldehyde Acetaldehyde Toluene Xylene

A growing body of scientific evidence suggests that the air within buildings can be more seriously polluted than the outdoor air (USEPA 2008); and that the construction products which occupy large surface areas – floors, walls and ceilings, are the single most important source of indoor air contaminants (Levin, 2010). Other research findings suggest that people spend up to 90% of their time indoors (GreenGuard, 2011). Such relatively long term exposure to low doses of chemical pollutants can result in moderate to serious systemic harm that does not reverse itself when an occupant leaves a building - this constitutes the most important potential exposure in respect of human health (Hodgson & Alevantis 2004). From an indoor air quality (IAQ) perspective, the key chemicals of concern are Volatile Organic Compounds (VOCs) and Semi-Volatile Organic Compounds (SVOCs) used in the manufacture of furniture, upholstery, cleaning supplies and a broad range of construction products found in the indoor environment Trends in the development and use of standards for certifying the indoor/outdoor environmental performance of building products are discussed in the sections which follow.

ISO 14020 certification programmes

The ISO 14020 Series of standards Environmental Labels and Declarations comprises ISO 14021(1999): Type II Self-declared Environmental Claims; ISO 14024 (1999): Type I Environmental Labelling; and ISO 14025 (2006): Type III Environmental Declarations. These documents are supported by a fourth document: ISO 14020 (2000): General principles. The overall objective of this series of standards, internationally accepted as best practice on environmental labelling is to (ISO, 2000):

11 Net Zero Energy Building (NZEB) means a building which produces as much energy as it draws from the grid, effectively reducing its operating energy to zero. the green building HANDBOOK

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• Communication verifiable and accurate information - which is not misleading in anyway - on the environmental aspects of products and services; • Encourage the demand and supply of those products and services that cause less stress on the environment: and • Stimulate the potential for market-driven continuous environmental improvement.

ISO 14021(1999): Type II Self-declared Environmental Claims As its title suggests, ISO 14021 is a standard for first-party claims therefore the criteria setting, product assessment and verification and certification protocols are all under the control of the product manufacturer. The standard is intended for business-to-consumer communication by means of statements or symbols. To foster the verification of a Type II claim, the methodology underpinning a claim needs to be scientifically sound. There is however no requirement to use Life Cycle Assessment (LCA) in any of its forms. To prevent unwarranted claims, ISO 14021 prohibits the use of vague or non-specific language such as “environmentally friendly” or “non-polluting” or “green” in a claim. Arguing that there are no definitive methods for measuring sustainability, the international standard specifically excludes usage of the terms “sustainability” or “sustainable” in the contents of a first-party claim.

Table 5.2: ISO Type II certification programmes

Programme name

Country/ region

Environmental area of protection

Description

SCS12 recycled and material content certification

USA

Outdoor

Private (3rd party). Limited to building products only

Energy Star13

USA

Outdoor

National (voluntary, 3rd party) programme. Covers building products including whole buildings

Type II labels are typically marketed on the basis of only one environmental attribute, for example, energy efficiency, with a risk that possibly adverse environmental impacts are not made known to the consumer. This label type is the most frequently dogged by concerns of “green washing”14. Many manufacturers are now resorting to second15 or third16 party certification to boost the public image of Type II labelled products - both of the examples given in Table 5.2 above conform to this trend which is a positive deviation from the intents of ISO 14021.

By contrast to the requirements for Type II labelling, the standards for Types I and III labelling have the following built-in features, designed to foster transparency, impartiality and credibility in the market place, namely: • Independent, third-party verification and certification of product claims.

• A whole life cycle assessment based on multiple criteria so that all environmental consequences of a product are identified and addressed in a holistic manner.

• Thorough consultation; and participation of stakeholders (producers, consumers, authorities, etcetera) in the standard development process

12 http://www.SCScertified.com 13 http://www.energystar.gov 14 To “green-wash” means to mislead consumers regarding the environmental practices of a company or the environmental benefits of a product or service (available at http://sinsofgreenwashing.org/ ) 15 Second-party certification implies that an interest group that stands to gain in some way from the increased market share of the product, has critical involvement in the certification process, either through administration of the programme, verification of claims or creation of standards and methods 16 Third-party certification refers to certification programmes in which all aspects of the programme are administered by an independent body whose only ties to product manufacturers are fees for assessment services. the green building HANDBOOK

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ISO 14024 (1999): Type I Environmental Labelling A Type I label is commonly known as an “ecolabel”. It conveys business-to-consumer information in the form of a symbol or seal of approval which confirms the environmental preferability of a labelled product within a specific product category. For example, an ecolabel serves to distinguish between an environmentally preferable or “green” carpet and a conventional carpet but not other floor coverings.

An ecolabel is awarded by an impartial third-party who operates an ecolabelling programme17 which sanctions the use of the label. The relationship between LCA and ecolabelling lies in the criteria setting. ISO 14020 requires that the criteria be based on life cycle considerations – that is, the criteria selection process shall consider in a qualitative manner the function of the product (or service); and all life cycle stages18 and embodied effects19 associated with the product in question. The first Type I ecolabelling programme set up was the German Blue Angel, in 1978. Type I programmes now exist all over the world, though most are found in the developed countries. The Global Ecolabelling Network (GEN), a non-profit body representing Type I ecolabel programmes, has twenty-seven members made up of regional, national and privately run programmes.

Table 5.3: ISO Type I certification programmes

Programme name

Country/region

Environmental area of protection

Description

Nordic Swan20

Nordic countries

Outdoor /indoor

National (voluntary, 3rd party) cross-sectoral programme of the Nordic countries. Covers all building products including whole buildings, e.g. homes

Blue Angel21

Germany

Outdoor / indoor

National (voluntary, 3rd party) cross-sectoral programme. Covers building products and construction equipment

SCS Indoor22 Advantage Gold

USA

Indoor

Private (3rd party) programme. Limited to products used indoors, e.g. decorative paints, hard surface flooring and insulation.

RFCI FloorScore23

USA

Indoor

Industry (2nd party) programme. Limited to resilient flooring and hard flooring systems and their adhesives

Though ecolabelling programmes cover a wide range of different products only a few include building product labels – they are Nordic Swan (Nordic countries), Blue Angel (Germany), Environmental Label (China), Eco-label (Czech Republic), Green Seal (USA), Ecolabel (European Union) and Ecomark (India). A few ecolabel programmes have also emerged in the USA in recent years which apply only to products used within an enclosed indoor environment. Table 5.3 provides examples of ecolabelling programmes.

ISO 14025 (2006): Type III Environmental Declarations This label type, commonly known as an Environmental Product Declaration (EPD), represents the closest link between LCA and the environmental labelling of products. EPDs foster the environmental comparison of products fulfilling the same function, based on objective, quantitative information. As a declaration, an EPD simply discloses the environmental performance of products and expects the 17 Programme and scheme are used interchangeably in the literature 18 Extraction of raw materials, manufacture, distribution, use and disposal 19 Input of key resource (energy, materials, water), release of pollutants (to air, water and soil) and contribution to environmental problems (human and ecological health and natural resource depletion) 20 http://www.svanen.se/en/Nordic-Ecolabel/ 21 http://www.blauer-engel 22 http://www.scscertified.com/gbc/indooradvgold.php 23 http://www.carpet-rug.org/

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consumer to judge which product is best in an environmental sense. An EPD is intended for businessto-business communication but its use in business-to-consumer communication is not precluded.

An EPD needs to be developed in conformance with Product Category Rules (PCRs), that is, highly standardised procedures for conducting quantitative LCA24 on a product in order to achieve results which are transparent, consistent and scientifically robust. As ISO 14025 is a generic standard, a further ISO standard, ISO 21930: 2007, Sustainability in building construction – Environmental declaration of construction products has been developed to provide a framework for construction productspecific PCRs. The certification of an EPD results in the issuing of a report card which provides detailed product environmental information, akin to the nutritional label on food products. Internationally, EPD programmes are represented by the Global Environmental Declarations Network (GEDnet). The first EPD programme was launched in Sweden in 1998.

Table 5.4: ISO Type III construction product certification programmes

Programme name

Country/ region

Environmental area of protection

Description

BRE Global 25 Environmental Profiles

UK

Outdoor

National (voluntary, 3rd party) building sector-specific programme.

Covers all building products - materials, components and whole buildings

AUB 26

Germany

Outdoor

National (voluntary, 3rd party) building sector-specific programme.

Limited to building materials and components

The Green Standard27

USA

Outdoor

Private (3rd party) building sector-specific programme. Limited to building materials and components

RT28 Environmental Declaration

Finland

Outdoor

Private (3rd party) programme supported by government. Limited to building materials and components

Ongoing developments which point to an increasing role for EPDs as a fundamental tool for Sustainable Construction include: • A more rapid development of building sector-specific EPD (Type III) programmes as compared to the limited number of cross-sectoral Type I programmes which carry a few building product labels.

At least ten of such programmes have been launched in Europe and North America since the late 1990s (Chevalier et al, 2004). Examples are given in Table 5.4.

• An EPD standard for building products, which is currently under development, and is likely to become a US national standard, subordinating existing Types I and II labels (Leonardo Academy, 2008).

• Development of a harmonised, European EPD standard for construction products to be published in 2012 (BRE Group, 2011).

• Obligatory EPDs for construction products as required under France’s Le Grenelle de L’Environnement which came into effect in early 2011 (Schenck, 2009).

Indoor air quality performance certification programmes

The purpose of indoor air quality (IAQ) performance labelling is to foster the development and use of low-emitting construction products which have been shown to improve IAQ without a need to increase ventilation rates. Labelling is preceded by the development of emissions standards which 24 The LCA behind an EPD must comply with the ISO 14040 Series of standards: Environmental Management – Life Cycle Assessment 25 http://www.bre.co.uk 26 http://www.bau-umwelt.com 27 http://www.thegreenstandard.org 28 http://www.rts.fi the green building HANDBOOK

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meet or exceed nationally regulated exposure limits to the chemicals of concern. Certification results in the disclosure of environmental performance without claims of environmental superiority.

IAQ labels are characterised by statements such as “very low emissions PLUS” (EMICODE, 2011) and “Formaldehyde free” (GREENGUARD, 2011b).

IAQ certification programmes, which rely on voluntary participation by product manufacturers, take the form of environmental testing and labelling or comprehensive environmental evaluation and certification. To foster credibility, certification programmes are subject to second or third-party certification; and make provision for stakeholders to participate in the selection of evaluation criteria and the development of test standards.

Table 5.5: IAQ performance certification programmes

Programme name

Country / Region

Environmental area of protection

Description

M1 Classification29 Scheme

Finland

Indoor

Private (3rd party) programme promoted by government for building products, e.g., wall and floor coverings

GreenGuard Indoor Air30 Quality (Type I)

USA

Indoor

Private (3rd party) programme for building products, promoted by government, e.g., countertops, cabinetry and doors

Indoor Climate Label31

Denmark

Indoor

Industry (3rd party) programme promoted by government for building products and other products used in the indoor environment

EMICODE32

Germany

Indoor

Industry (3rd party) programme limited to building products for installation of floor coverings, e.g. screed.

A common feature of IAQ certification is that the labelling of a product is generic. Product emissions testing takes place under standardised test conditions which foster comparison between products but cannot take into account the actual application context, for example, ventilation rates. Testing includes short (3-day) and long-term (28-day) assessment. The results of emission testing can be expressed as pass / fail in relation to a single Volatile Organic Compound (VOC) or Total Volatile Organic Compound (TVOC) limit value.

A major challenge for more widespread use of IAQ performance labelling to enhance indoor environmental quality is that the development of standards will require emissions, exposure and human health effects data. However, such data are currently insufficient or lacking because most nations do not have the regulations to limit or prevent exposure to indoor air contaminants. Emerging regulatory activity which holds promise for the future of IAQ performance labelling of construction products include: • The European Union’s Construction Product Directive (CPD) of 1989 and Construction Product Regulation (CPR) of 2011 both require that no construction product should cause harm to occupants of buildings. To satisfy this requirement, the European Commission mandated CEN to develop harmonised test standards for the emissions of regulated dangerous substances into indoor air from building products and furniture (CEN, 2011).

• The EU Member States are also taking individual action to meet the requirements of the CPD and CPR. Germany has a restriction on VOC emissions from construction products which has formed the basis for mandatory testing of floor coverings and their adhesives since 2004 (Levin, 2010). In March 2011, France published mandatory labelling requirements for construction products installed 29 http://www.rakennustieto.fi 30 http://www.greenguard.org 31 http://www.dsic.org 32 http://www.emicode.com the green building HANDBOOK

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indoors. The regulation is effective from January 2012. The construction product groups covered by the French regulation include but are not limited to floor and wall coverings, ceiling systems and all products used in their installation (Eurofins, 2011).

The European REACH33 policy which in February 2011 imposed a ban on five chemicals used in construction products. The targeted substances include three phthalates34, HBCDD35 and MDA36. The ban impacts on the supply chains of a number of common construction products including PVC, foam insulation, carpet backing, adhesives and composite wood products (HBN, 2011).

• The Building Standards Law of Japan stipulates mandatory testing of all construction materials against a standard for emissions rates of VOCs into the indoor environment (Levin, 2010). The Japanese standard currently covers building boards, wall paper, floor coverings, adhesives, decorative paints and coatings and heat insulating materials.

South African state-of-the-art

Policy context

The use of environmental labelling as an instrument for sustainable development is not new in South Africa. The Constitution, Act 108 of 1996 makes provision for an Environmental Right37; and also guarantees access to environmental information38 required to protect that right. The White Paper on environmental management policy for South Africa (1998) makes specific reference to eco labelling39 as a means for industry to take greater responsibility for environmental protection40; and for the consumer public to gain access to environmental information41, signalling that the minimum preferred national standard for environmental labelling ought to be the ISO Type I Ecolabel which is based on multiple life cycle criteria; and requires public consultation and third-party certification.

This policy position has been transcribed in key items of consumer and environmental legislation. For example, the Air Quality Act of 2004 requires the use of environmental labelling to achieve emissions reductions targets; and the minimum requirements set out by the Consumer Protection Act of 2008 include labelling of products which may result in hazardous waste.

However, in practice, the degree of environmental awareness of the consumers in a particular country or region will determine whether a market for “green” products is initiated and can be sustained. In the context of South Africa, there has been extensive media coverage linking the building life cycle to the most prominent environmental issues of the current era, that is, energy security and climate change.

This has served to stir up an interest in environmental protection by both producers and consumers, creating the necessary momentum for the demand and supply of green buildings and construction products.

Status of environmental labelling in the SA construction industry sector

Green Star SA The notion of rating and certifying South African buildings as “green” first came into prominence when the Green Building Council of South Africa (GBCSA) launched its first Green Star SA tool in November 33 Registration, Evaluation and Authorisation of Chemicals (REACH) is the regulation that governs the management of chemicals in the European Union 34 The banned substances are known hormone disrupting reproductive toxicants used in flexible PVC products such as vinyl flooring 35 A persistent, bio-accumulative toxicant (PBT) widely used as a flame retardant in polystyrene foam insulation 36 A know, potent carcinogen used as a basic building block in the manufacture of polyurethane foams and some composite wood binders.

37 Section 24 of the Constitutional Bill of Rights 38 Section 32 of the Constitutional Bill of Rights 39 Government Gazette dated 15 May 1998 - Chapter 5: Governance – indirect measures, page 54.

40 Government Gazette dated 15 May 1998 – Chapter 4: Strategic goals and objectives, page 31.

41 Government Gazette dated 15 May 1998 – Chapter 3: Principles, page 24.

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2008. To date, four rating tools for office, retail, multi unit residential and public and education buildings have been published. The overall aim of GBCSA is to develop building rating tools, based on the Australian Green Building Council tools, to provide the South African property industry with an objective measurement for green buildings and to recognise and reward environmental leadership in the property industry. As a whole building assessment and rating tool, Green Star SA awards credits for the choice of environmentally sound construction products but cannot in any way test, verify or certify the environmental performance of such products. Emerging environmental standards and initiatives which respond to, and also complement the “green” marketing opportunity created by Green Star SA are discussed in the sections below.

EcoStandard South Africa EcoStandard South Africa is a non-profit body aiming to provide impartial, third-party environmental certification services for construction products. The basis for environmental performance assessment and labelling will be EcoProduct, a tool founded on the principles and procedures of the Type I environmental labelling standard, ISO 14024: 1999. EcoStandard completed a pilot project in 2011 and intends to launch its construction product certification programme, which will rely on voluntary participation by construction product manufacturers, in January 2012.

Energy labelling standard for buildings SANS 204 Energy Efficiency in Buildings, released for final comment in March 2011, is a national standard for energy labelling of buildings. It is set to mainstream energy efficient building in South Africa as it specifies minimum energy usage requirements to be met by all building types, whether ventilated naturally or artificially. In terms comparable to that of ASHRAE’s bEQ, SANS 204 requires an energy audit to be conducted twelve months after completion of a new building as proof of compliance with the benchmark set for the building type. SANS 204 is currently subject to voluntary application in new buildings but can be used for the retrofitting of existing buildings. A process is currently underway to translate the General Requirements of this historic national standard into enforceable provisions under the National Building Regulations (NBR). SANS 204 has been developed to support the implementation of building sector-specific targets set under the National energy efficiency strategy of the Republic of South Africa (2005) which sets a national long term target for energy demand reduction of 12% by 2015.

South African National Ecolabelling Scheme The goal of the South African National Ecolabelling Scheme (SANES), a government funded initiative established in 2007, is to create an enabling environment for South Africa to achieve an important environmental policy milestone – that of using industry self-regulation to complement environmental regulation. SANES provides third-party certification of environmental claims in accordance with principles and procedures of the Type I environmental labelling standard, ISO 14024: 1999. Participation in SANES is voluntary. The stated objectives of SANES are to: • Unite the growing number of environmental claims “under one umbrella”; • Provide environmental assessment, certification and labelling services for all South African industry sector products; • Enhance the market share of “green” products: and • Encourage new actions which will enhance biodiversity, minimise waste and pollution and conserve resources (water and energy) To date, SANES has developed and piloted ecolabels for domestic cleaning products and the tourism sector. There is currently a process underway to develop SANES ecolabels for construction products.

SANES is administered by Indalo Yethu, a legacy project of the Third Earth Summit which was held in Johannesburg in 2002. Indalo Yethu was created by the Department of Environmental Affairs (DEA) in 2003. the green building HANDBOOK

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Materials manufacturing industry initiatives The results of a desk top survey on the “green” initiatives of leading South African manufacturers of construction products suggests that “green” marketing is established and growing. Nine out of twenty-one major construction material groups already feature an environmentally sound or “green” brand. There is however a strong trend in ISO Type II Self-declared claims and therefore a high risk of loss of consumer confidence due to fears of green washing. Furthermore, five out of the nine major material groups identified in the survey (Table 6) - floor covering; decorative paint; doors, windows and frames; particleboard and medium density fibreboard (MDF); and insulation are known to have a negative influence on indoor environmental quality and should therefore be labelled with IAQ performance in mind. However, with the exception of one floor covering brand, the “green” claims identified in the survey are concerned with energy use and GHG emissions / the protection of the outdoor environment.

Table 5.6: South African construction product certification and labelling trends

Construction product group

Certification trend

Environmental area of protection / labelling criteria

Cement

First-party

Outdoor – energy and air quality (GHG emissions)

Masonry

First-party

Outdoor – materials, energy and air quality (GHG emissions)

Floor covering

Third-party

Outdoor/indoor, materials, energy , air quality (GHG emissions and IAQ)

Decorative paint

First-party

Outdoor – air quality (VOC emissions)

Doors, windows and frames

Third-party

Outdoor, Forest Stewardship Council (FSC) certified

Particleboard and MDF

First-party

Outdoor – materials, energy and air quality (GHG emissions)

Glass and mirrors

First-party

Outdoor – materials, energy and air quality (GHG emissions)

Insulation

First-party

Outdoor, air quality (CFC and HCFC emissions)

Lessons learnt

Environmental labelling emerged in the 1980s in response to growing global concerns for environmental protection and conservation. In the construction industry sector, environmental labelling serves to incentivise sustainable construction which is an important component of society’s quest for sustainable development. It has evolved at two distinctive levels namely, whole building rating; and construction product certification.

Building environmental assessment and rating systems develop voluntary standards against which the environmental performance of candidate buildings is assessed, certified and rated. However, there is a mismatch between the performance assessment principles and practices of the first generation building rating systems; and what is needed to foster sustainable construction. Furthermore, the voluntary nature of building certification and rating has to date failed to create the critical mass of “green” buildings needed to accelerate the building sector’s shift towards patterns of sustainable consumption and production, a precondition for sustainable development.

Second generation building assessment and rating systems, which are still evolving, are beginning to address these concerns. Their key features include: • Promotion of shared methods of performance certification and rating to avoid confusion in the globalised marketplace and increase the credibility and demand for “green” building • Adoption of LCA principles and quantitative criteria which enable performance to be assessed against the absolute impact that a building system exerts on the environment

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• Development and adoption of economic and social indicators to foster a shift from sustainable construction, which addresses only environmental concerns, towards sustainable building which seeks to address all three dimensions of sustainability • Increasingly serving as a source of minimum, enforceable environmental standards that local and national authorities can apply to all buildings to mainstream “green” building In parallel with the second generation building rating tools, standards for the energy labelling of buildings are being developing at national, regional and global levels. The overarching objective is to give the sector which represents 40% of the world’s energy consumption quantitative, transparent tools to drive both existing and new buildings towards net zero energy building (NZEB). The energy labelling of buildings supports mandatory disclosure of building energy performance, an approach which has already been mainstreamed in the EU since 2005, and is now emerging across the USA. The purpose of construction product certification is to minimise the outdoor environmental effects of buildings; and create a healthier indoor environment for building occupants. The basis for construction product certification is the ISO 14020 series of standards, Environmental Labels and Declarations. LCA, which is the main analysis method for this standard, is suitable for measuring the potential environmental effects of a construction product on the outdoor environment, but not the environmental risks associated with the use of that product in the indoor environment. Two principal types of construction product certification programmes have therefore emerged, ISO 14020 certification programmes; and IAQ certification programmes.

Of the three environmental labelling standards provided by ISO 14020, Type I Ecolabel and Type III EPD rely on multiple, LCA-based assessment criteria and make provision for public consultation and third-party certification which fosters credibility and impartiality. Furthermore, Type III EPD forms the basis for the building sector-specific standard ISO 21930: 2007, Sustainability in building construction – environmental declaration of building products which is playing an increasingly prominent role in the development of second generation building rating systems and the implementation of national and regional environmental policy. By contrast, the Type II Self-declared claim is prone to concerns of “green washing” therefore users of this standard are resorting to second or third-party certification to boost the public image of their “green” claims.

The purpose of IAQ performance labelling is to foster the development and use of low-emitting construction products which have been shown to improve IAQ without a need to increase ventilation rates. Mandatory IAQ labelling of construction products installed indoors to protect public health and safety is an established practice in many EU member states and Japan. A major challenge for international adoption of this approach is that most nations lack the human health effects data; and do not have the regulations to limit or prevent exposure to indoor air contaminants.

In the context of the South African construction industry, the launch of Green Star SA in 2007 and the ongoing efforts to develop and adopt other voluntary environmental standards for whole buildings and construction products respond to the environmental policy expectation that business and industry will take greater responsibility for environmental conservation and protection through self-regulation.

The policy provision presupposes that the development of voluntary environmental standards, such as Green Star SA will be sufficient to stimulate the environmental improvement of individual buildings and major construction products, result in collective reduction in the environmental burdens attributable to the sector, and thereby serve as an input to national sustainable development targets.

However, the international literature suggests that a voluntary basis for building rating and construction product certification encourages a niche market whereas a more mandatory approach, driven by enforceable minimum environmental standards for all buildings, is necessary to garner the critical mass which meets such national policy expectations. Bearing in mind the key components of the emerging framework for environmental labelling In the South African building sector, comprising: 92

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• Environmental policy provision/reference to ISO Type I Ecolabel which is based on multiple life cycle criteria; and requires public consultation and third-party certification as the minimum requirement for environmental labelling • First generation whole building rating system / Green Star SA • Whole building energy labelling standard / SANS 204 • Established or emerging ISO Type I Ecolabels and ISO Type II Self-declared claims The following complementary measures would at a minimum be needed in the short term to consolidate the gains made, and drive the South African framework towards current best practice in building rating and construction product certification: • Environmental standard or family of standards, applicable to all buildings, which complements SANS 204 by seeking to mainstream enforceable, minimum requirements in respect of site development, materials, water, indoor air quality (IAQ) and commissioning • A national regulation which stipulates public consultation and third-party certification as minimum requirements for environmental labels, claims and declarations • A construction product regulation which makes provision for the restriction, substitution or elimination of harmful substances used in the formulation of construction products installed indoors, and will therefore create an enabling environment for the development of IAQ labels for construction products

References

AQS, 2010. Defining green products. Available at http://www.aqs.com Blom, I., 2006. Environmental assessment of buildings: bottlenecks in current practice. In ENHR International Conference, Ljubljana, July.

BRE Group, 2011. Impact of CEN TC 350 standard analysed. http://www.bre.co.uk/page.jsp?id=2747 CEN, (undated). Conclusions about the needs for development of sustainability indicators and assessment methods. Available from: cic.vtt.fi/superbuildings/ sites/default/files/D2.1_Final.pdf (Accessed 05 December 2011).

CEN, 2011. Energy performance of buildings. Available from: http://www.cen.eu/cen/Sectors/Sectors/Construction/SustainableConstruction (Accessed on 05 December 2011) CEN, 2011. /IAQ. Chevalier, J., Chevalier, J.L. and Cuenot, S., 2004. From LCA to EPD in construction: a strategic point of view. Available from: www.irbdirekt.de/daten/iconda/ CIB9754.pdf (Accessed on 30 November 201).

Cole, R.J., 1998. Emerging trends in building environmental assessment methods. Building Research and Information, 26(1), 3-16.

Edwards, B., 2002. Rough guide to sustainability. London: RIBA Publications EC, 2009. Executive summary report on the interim conclusions of the concerted action EPBD. Available from: http://www.epbd-ca.org/index.cfm?cat=news (Accessed on 21 November 2011).

EMICODE, 2011.

Eurofins, 2011. – French regulations on VOC emissions from construction products. Available at http://www.eurofins.com/product-testing-services/topics/ compliance-with-law/european-national-legislation/french-regulation-on-voc-emissions.aspx GREENGUARD, 2011a. Sustainable design and green interiors for designers and architects. Available from: http://www.greenguard.org/en/ArchitectsDesigners. aspx GREENGUARD, 2011b. GREENGUARD Environmental Institute formaldehyde free verification. http://www.greenguard.org/en/CertificationPrograms/ Formaldehyde HBN, 2011. European chemical ban will REACH US building materials. http://www.healthybuilding.net/news/110222-european-chemicl-b Hodgson, A. & Alevantis, L., 2004. Testing of Building Products for Emissions of Volatile Organic Compounds: Practical Time Point for Assessing Potential Chronic Health Impacts, California Department of Health Services.

ISO, 2000. 14020 (2000): General principles.

Jarnagin, R.E., 2009. ASHRAE Building EQ. ASHRAE Journal, December 2009. Available from: http://www.ashrae.org Jönsson, Å., 2000. Is it feasible to address indoor climate issues in LCA? Environmental Impact Assessment Review, 20(2), 241-259.

Kibert, C.J., 1994. Establishing principles and a model for sustainable construction. In Sustainable Construction-Proceedings of the First International Conference of CIB TG. Levin, H. 2010. National programs to assess IEQ effects of building materials and products. Available from: www.epa.gov/iaq/pdfs/hal_levin_paper.pdf Reuters, 2009. A new building energy label in the works, alternative to Energy Star. Available from: http://www.reuters.com/articlePrint?articleId= US65589751120090810 (Accessed on 09 November 2009).

SBA, 2011. SB Alliance – what is it about? Available from: http://www.sballiance.org/about (Accessed 21 November 2011). the green building HANDBOOK

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SBA, 2009. A proposal for the Sustainable Building Alliance core set of indicators. Available from: http://www.sballiance.org/toolsandresearch (Accessed 21 November 2011).

SB.com, 2011. First national green building code approved. Available from: http://sustainablebusiness.com/index.cfm/go/news (Accessed on 21 November 2011).

SEDA, 2007. Design and detailing for toxic chemical reduction in buildings: the issues. Available from: http://www.seda.uk.net/dfcrb/ch3.htm.

Schenck, R. 2009. The outlook and opportunity for Type III environmental product declarations in the United States of America. Available from: www.lcacenter. org/.../Outlook-for-Type-III-Ecolabels-in-the-USA.pd. (Accessed November 2010) UNEP-SBCI, 2009. Common carbon metric for measuring energy use and reporting greenhouse gas emissions from building operations. Available from: www. unep.org/sbci/pdfs/UNEPSBCICarbonMetric.pdf (Accessed 21 November 2011).

USEPA, 2008. The Inside Story: A Guide to Indoor Air Quality. Available at: http://www.epa.gov/iaq/pubs/insidest.html.

Zimmerman, A. and Kibert, C., 2007. Informing LEED’s next generation with the natural step. Building Research and information, 35(6), 681-689.

(Footnotes)

1 http://www.SCScertified.com 2 http://www.energystar.gov 3 http://www.svanen.se/en/Nordic-Ecolabel/ 4 http://www.blauer-engel 5 http://www.scscertified.com/gbc/indooradvgold.php 6 http://www.carpet-rug.org/ 7 http://www.bre.co.uk 8 http://www.bau-umwelt.com 9 http://www.thegreenstandard.org 10 http://www.rts.fi 11 http://www.rakennustieto.fi 12 http://www.greenguard.org 13 http://www.dsic.org 14 http://www.emicode.com

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PROFILE

Corobrik This profile presents a synopsis of Corobrik’s focus areas in the ongoing ‘greening’ of its business and the key factors that define the environmental integrity of Corobrik bricks in lifecycle terms.

Making Corobrik’s business Greener Quarrying of Clay Materials: • Quarrying and manufacturing operations are strictly managed within a sustainable development framework that includes social and labour plans and approved environmental management plans.

• Concurrent rehabilitation of all quarries during annual quarrying operations with final rehabilitation to be carried out to ensure the quarry site continues to offer future generations’ equal potential for use and development.

Wider Use of Cleaner Burning Fuels: For each giga joule of energy, natural gas releases just 48kgs of CO₂ compared to 97kgs of CO₂ emitted from coal. In 1996 Corobrik committed to a process of converting to natural gas for the firing of its kilns.Today, Corobrik has six major factories using natural gas as a primary fuel source for the firing of its kilns, bringing to the South African market clay bricks with embodied energy values in line with best international practice for the clay types and the manufacturing technologies employed.

Further conversions are being pursued but remain dependent on the availability of natural gas at the factory gate.Corobrik has the distinction of being the first company in South Africa to be issued Certificates of Emissions Reductions by the United Nations Clean Development Mechanism for its fuel switch programme – Lawley Factory conversion.

Dematerialization through Advanced Manufacturing Technologies: Achieving dematerialization with enhanced product quality and performance attributes and energy usage reductions is an ongoing endeavour.

The recent progressive conversion of extrusion technology to a ten core configuration that increased brick perforations to approximately 35%, included:  Reductions in drying and firing energy usage in the order of 20 percent when compared to a ‘standard’ 3 core-hole brick with 20 percent perforations.  Reduced diesel usage per thousand bricks delivered.  An 8% reduced mortar usage on site reducing the carbon footprint associated with the cement component of mortar.

SANS 14000 Accreditation Corobrik is working towards SANS 14000 accreditation at its four SANS 9001:2008 certificated factories during the first quarter of 2012 as a precursor to extending SANS 14000 accreditation to all Corobrik factories.

Embodied energy of Corobrik masonry materials as walling systems The Carbon Footprint of Corobrik bricks:

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PROFILE Life Cycle Assessment has established that irrespective of house construction type embodied energy comprises no more than 10% of total energy consumed over a 50 year life cycle. Heating and cooling energy comprises up to 40% of total energy consumed. Significant empirical and thermal modeling studies into the thermal performance of walling envelopes for houses confirms thermal mass inherent in clay brick walling as a critical thermal performance property for achieving thermal comfort and lowest heating and cooling energy usage necessary for lowering South Africa’s carbon footprint.

Lowest heating and cooling energy is achieved with double clay brick construction Comparative Thermal Comfort: Thermal discomfort drives behaviour to achieve comfort. The CR Product research by WSP Energy Africa (Prof D Holm and HC Harris) established a strong correlation between walls with high thermal capacity ‘C’ as provided by clay bricks and target thermal comfort.

130 m² Standard House Study: WSP Green by Design (Design Builder Energy Plus Software)

The above graph depicts how a double skin clay brick walled house with appropriate resistance contributes most to thermal comfort and energy reductions for heating and cooling. LSFB SANS 517 and 204 compliant insulated lightweight walling [reference 5.1 and 5.2] demonstrate little propensity to self regulate resulting in ‘hotbox’ conditions in the hot summer months and highest annual cooling energy requirements.

Specifying for optimal Thermal Efficiency and Payback: 132 m² CSIR House Study: Structatherm Projects (Visual DOE software): Clay brick walls that combine their inherent thermal capacity with appropriate levels of insulation for the climatic zone provide for optimal energy efficiency with the best payback. The SANS 204 compliant insulated clay brick walled house outperformed the LSFB SANS 204 compliant house in terms of heating and cooling energy usage and cost, by between 30% and 60% depending on the climatic zone.

Energetics Full Life Cycle Assessment: Double skin clay brick wallings’ superior thermal performance attributes were again highlighted in this major comparative study that considered two house types in three climatic zones, four orientations and with five different walling envelopes. While design is recognized as having the biggest impact on heating and cooling energy requirements, passive solar design with thermal mass is necessary

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PROFILE for energy efficiency optimization. In this study both double brick un-insulated and insulated walled houses well outperformed the timber frame insulated weatherboard alternate reducing operational energy usage on average by 16% and 26% respectively.

Comparative lifecycle carbon footprints of walling systems Corobrik clay brick walled houses thermal properties, low maintenance attributes and longevity offers the propensity to amortise their embodied energy over a 50 year life cycle. Two studies that demonstrate clay brick construction affording lower total [embodied plus operational] Greenhouse Gas emissions over a defined lifecycle include: 40 m² Low Cost House Study:

In this study Corobrik two leaf brick accounted for a total 50.1 tons of CO2 this 10.2 percent less than the SANS 204 compliant LSFB insulated lightweight walled alternate located in Johannesburg over a 40 year life cycle. Cavity and insulated brick offered further improvements on this.

Energetics Full Life Cycle Assessment: This study established that in the case of the Verdant house plan the HVAC energy savings of the double skin clay brick houses, both with and without insulation, translated into lower total (embodied and operational) Greenhouse Gas emissions over 50 years.

Holistic environmental value Within the environmental sustainability equation Corobrik offers clay bricks with embodied energy values in line with international best practice for the technologies employed and with thermal performance properties that support superior thermal comfort and lowest operational energy usage outcomes. Add this to the many generic factors that underpin clay bricks’ environmental integrity, namely durability and longevity, reusability and recyclability, inertness that ensures no release of VOC’s or toxic fumes to impinge on air quality, incombustibility, natural sound insulation qualities, inorganic quality that is not a food source for mould, maintenance free qualities of face brick that incur no future carbon debt, earthy colours and textures that sit unobtrusively in natural environments and Corobrik bricks present designers an opportunity to achieve sustainable buildings of quality with due sensitivity to the environmental imperatives of the time.

Contact Details: Tel: +27 (031) 560-3111 Email: intmktg@corobrik.co.za Website: www.corobrik.com

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chapter 6: Optimising Daylight in South Africa: A Case Study

Optimising Daylight in South Africa: A Case Study Dr Dirk Conradie Senior Researcher Built Environment CSIR

Introduction

This chapter must be read in conjunction with previous chapters in The Green Building Handbook, i.e. Lighting (Osburn, 2010), Maximising the Sun (Conradie, 2011), SA Climate Zones and Weather Files (Conradie, 2012). The first chapter mentioned discusses artificial lighting. The second chapter describes inter alia the amount of direct and diffuse solar radiation received and discusses in detail the calculation of solar angles. This is fundamental to understand the design of a natural daylight system and appropriate solar protection. The last chapter provides an insight into the characteristics of the various climatic regions of South Africa. Climate impacts directly on the amount of natural daylight available and the appropriate orientation, size and position of windows and a wide range of other possible daylight systems.

Light is of decisive importance in experiencing architecture. The same room can be made to give very different spatial impressions by a simple expedient of changing the size and locations of its openings.

Moving a window from the middle of a wall to a corner will utterly transform the entire character of the room. To most people a good light means only much light. If we do not see a thing well enough we simply demand more light. And very often we find that it does not help because the quantity of light is not nearly as important as its quality. (Rasmussen, 1964) At the moment lighting accounts for around 35% of the energy used within non-residential buildings and between 0% and 28%1 in residential buildings. Electricity usage (%) in the residential sector for high/ middle income residences consume typically 5% for fluorescent and 12% for incandescent types of lighting. (UNEP, 2009). Designers are encouraged to use natural daylight in their designs to reduce the energy used (SANS 204-2, 2008).

The use of daylight to supplement or as a substitute for electric light in the window zones of interiors with side windows or over the entire area of spaces with skylights can save lighting energy.

This saving should be balanced against the energy required to compensate for heat gains and losses through the daylight openings. During times of low external temperatures more heating and during times of high external temperatures and sunshine more cooling of the interior will be required in order to maintain a constant internal air temperature. The use of daylight therefore will only be energy effective and cost-effective if the savings on lighting exceed the extra expenditure for climate control (SANS 10114-1, 2005)

1 0% is for an urban low income non-electrified house and 28% for a rural high-medium income, electrified house. the green building HANDBOOK

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Uses of daylight Table 6.1: The use of natural daylight. (Photographs by Author)

Uses for Natural Daylight Functional

Lighting for work Lighting for display Lighting for leisure Lighting in hospitals Lighting for indoor sports Lighting for circulation

A lecture hall with moveable ceiling that admits natural daylight when the projection screens are not used at the Stata Centre, MIT, Cambridge, Mass.

Fenestration and mesh solar protection for the new SANRAL building in Pretoria.

Decorative

The Genzyme building in Cambridge Mass. with an innovative computer controlled heliostat that provides decorative lighting effects in the atrium.

Artistic

An eastern facing artistic residential dalle de verre1 window in Pretoria gives a unique coloured light experience in the living space.

Natural daylight is a very important and interesting source of lighting in buildings. Natural daylight can inter alia be used for functional1, decorative2 and artistic3 purposes. In the SANS 204-2 and 10114-1 norms the emphasis is mostly on functional uses. The light levels, power and energy usage for the building is determined in accordance with a lookup table 14 (SANS 204-2, 2008).This table describes the recommended light levels, power and energy for various classes of buildings. The light levels range from 50 lx for entertainment and public assembly to 700 lx for high risk industrial type of spaces.

2 For a person to be able to move around in a building interior and to perform tasks safely and efficiently, both the total environment and the task shall be illuminated adequately and to acceptable levels.

3 Over and above the use of heliostats to drive electricity generation it can also be used as a means to provide interesting decorative lighting within a building.

4 Through the ages stained glass and lately dalle de verre has been used in buildings. The lighting effect is unsurpassed due to the special characteristic warm glow effect that the translucent coloured glass gives to spaces.

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The developments in electric lighting have not eliminated a widespread preference for daylight in buildings, wherever practicable. The reliance on daylight is greater in homes, offices, schools and patient areas in hospitals than in factories and shops.

The factors listed below will be different for different types of interior, different methods of daylight admission and for different climates (See Table 6.2). Recommendations regarding daylight should inter alia allow for the following factors (SANS 10114-1, 2005): Levels and uniformity. Daylight provides variability and, when it enters through side windows, creates a specific modeling and luminance distribution in the interior. It therefore contributes to visual satisfaction. The quantity of daylight is usually specified by the daylight factor, both with regard to illuminance and uniformity. In interiors with side windows, the available daylight decreases rapidly with distance from the windows. In many cases such as living rooms and small offices this non uniformity is acceptable and even appreciated. In other cases, supplementary electric lighting is required. Roof lights (skylights) can provide ample and highly uniform daylighting, but should be carefully designed to avoid solar overheating and glare.

• External view. Where natural light is used throughout the day for reasons of convenience and economy, an additional advantage is the view of the outside environment. However this is not always possible in large industrial or commercial buildings. The best position, shape and dimensions of the windows will depend on the nature of the outside environment. It also depends on the building design and will take into account architectural, lighting, visual, thermal and acoustic considerations.

• Glare from the sun or sky. Daylight can produce sky glare and can adversely affect the comfort in the interior. Direct sunlight is desirable for various types of buildings, such as homes in moderate climates, but should generally be avoided in work areas. Means to avoid direct sun irradiation are appropriate orientation of windows and skylights, the use of various types of curtains or blinds and the use of louvres or screens. The latter are also effective in reducing sky glare and are particularly important on the upper floors of high-rise buildings where large parts of the sky might be visible.

Small windows have an effect on the sky glare only to the extent that they prevent parts of bright skies or bright opposite facades or buildings from being seen. When appreciable areas of a bright sky remain in the field of view some glare such as discomfort5 glare or disability6 glare should be expected. Therefore, even with small glass areas, work areas directly facing windows should be avoided. If this is not possible, some means should be provided to reduce possible sky glare. Other techniques to reduce window glare are: • The use of external or internal devices, such as louvres.

• Deep splayed reveals on the side of the windows, finished with a high reflectance surface and with the same finish applied to any frames and glazing bars.

• The use of tinted low transmission glazing.

• Arranging for light in the interior to fall on the wall area adjacent to the windows, either from roof lights or from specially located luminaires.

• Heat gains and losses. The heat gain through windows might require cooling of the interior during the warm season, but might reduce heating costs during the cold season. However, heat losses through the window during the cold season can offset the savings and can increase heating costs.

The use of daylight as an illuminant can save energy used for electric lighting, but this should be balanced against the energy required to compensate for the heat gains and heat losses through the glazing. Means to avoid excessive solar heat are:

5 Discomfort glare is a less severe form of glare and as it name suggests causes discomfort and irritation rather than incapacity.

6 Disability glare can be so intense owing to the excessive contrasts or high illumination/ brightness levels in the field of view, that a person subjected to it will not be able to carry out a task such as reading or writing. the green building HANDBOOK

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• • • •

Appropriate orientation of glazing.

Reduction of areas of glazing.

Use of an appropriate daylight system (Table 6.2) Use of heat-reflecting or heat-absorbing glass or coated glass.

The International Energy Agency (IEA, 2000) recognizes a wide range of innovative daylight strategies and systems. Some are rarely used in South Africa. The IEA recognizes two basic types of daylight system i.e. daylighting systems with Shading and daylighting systems without shading. The latter type consists of four subdivisions: • Diffuse light-guiding systems • Direct light-guiding systems • Light-scattering or diffusing Systems • Light transport systems Table 6.2 below provides some examples of the various types.

Table 6.2: Different types of daylight systems (After IEA, 2000)

Shading Systems Name

Illustration

Climate

Location

Prismatic panels

All climates

Vertical windows and skylights

Prisms and venetian blinds

Temperate climates

Vertical windows

Sun protecting mirror elements

Temperate climates

Skylights and glazed roofs

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Anidolic zenithal opening

Temperate climates

Skylights

Directional selective shading system with concentrated Holographic Optical Element (HOE)

All climates

Vertical windows, skylights and glazed roofs.

Transparent shading system with HOE based on total reflection.

Temperate climates

Vertical windows, skylights and glazed roofs.

Light guiding shade

Hot climates and sunny skies

Vertical windows above eye height

Louvers and blinds

All climates

Vertical windows

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Light shelf for redirection of sunlight

All climates

Vertical windows

Glazing with reflecting profiles (Okasolar)

Temperate climates

Vertical windows and skylights

Skylight with Laser Cut Panels (LCPs)

Hot climates, sunny skies and low latitudes

Skylights

Turnable lamellas

Temperate climates

Vertical windows and skylights

Anidolic2 solar blinds

All climates

Vertical windows

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PROFILE

Vela VKE Consulting Engineers Bottling plant design leads the way in sustainability The opening in July of Coca-Cola South Africa’s new Valpre Spring Water bottling plant, situated south of Heidelberg, marked the completion of an extraordinary building.

VelaVKE Consulting Engineers has been an integral part of the project engineering team from inception in 2007. Gert Wentzel, Director of Development in the Johannesburg office led a team which included and advisor on the Leadership in Energy and Environmental Design (LEED) certification, an internationally accepted benchmark for design, construction and operation of high-performance green buildings. The team also included an advisor on the Leadership in Energy and Environmental Design (LEED) certification, an internationally accepted benchmark for design, construction and operation of high-performance green buildings.

The ValprĂŠ plant is a world class, state of the art, energy efficiency design build. Several unique features were built into the plant including daylight harvesting, energy efficient luminaires, rainwater harvesting, on-site treatment of effluent and the recycling of treated water. The plant also has a zero to landfill target.

Included in the design and operation of the plant are energy management systems, the installation of a solar power plant to power the offices, the use of materials with high SRI (Solar Reflectivity Index) values, the integration of service racks into the roof structure and the utilization of ammonia as a refrigerant.

The plant control room has been positioned to enable a 360 degree view of production operations. Fresh air supply is filtered to class 10 000 for hygienic reasons and the offices and other occupied areas are double insulated.

Local industry has benefited through the use of local material and businesses, and the plant is managed by a team of allblack women operators.

Contact Details

Group Head Office: +27 12 481 3800 Email: info@velavke.co.za Web: www.velavke.co.za

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Daylighting systems without shading Diffuse light guiding systems Light shelf

Temperate climates and cloudy skies

Vertical windows

Anidolic integrated system

Temperate climates

Vertical windows

Anidolic ceiling

Temperate climates and cloudy skies

Vertical faรงade above viewing window

Fish system

Temperate climates

Vertical windows

Zenith light guiding elements with HOEs

Temperate climates and cloudy skies

Vertical windows (especially in courtyards) and skylights

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Direct light guiding systems Laser cut panel

All climates

Vertical windows and skylights

Prismatic panels

All climates

Vertical windows and skylights

HOEs in the skylight

All climates

Skylights

Sun directing glass

All climates

Vertical windows and skylights

All climates

Vertical windows and skylights

Scattering systems Scattering systems

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Light transport systems Heliostat

All climates and sunny skies

Omni-directional

Light pipe

All climates and sunny skies

Omni-directional

Solar tube

All climates and sunny skies

Omni-directional

Fibres

All climates and sunny skies

Omni-directional

Light guiding ceiling

Temperate climates and sunny skies

Omni-directional

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architectural solutions

• Fixed external sun shading systems • Controllable external sun shading systems • Internal sun shading systems • Daylight guiding venetian blinds • High performance louvres • Ventilation louvres • Screening louvres • Acoustic louvres

• Potential for striking aesthetic impact • Reduced energy costs • Enhanced performance • Optimal lighting • Proven performance • Easy to install • A wide range

CONTACT DETAILS: HEAD OFFICE: +27 11 608 4640 • E-MAIL: info@robventind.co.za WEBSITE: www.robventind.co.za Sole Southern African distributor for Colt International & Warema GmbH products & systems

Creating a Healthier & Safer Environment

chapter 6: Optimising Daylight in South Africa: A Case Study

Luminance and illuminance

Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through or is emitted from a particular area and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/ m2). Luminance is often used to characterize emission or reflection from flat diffuse surfaces. The luminance indicates how much luminous power will be detected by an eye looking at the surface from a particular angle of view. Luminance is thus an indicator of how bright the surface will appear.

In this case, the solid angle of interest is the solid angle subtended by the eye’s pupil.

For a perfectly diffusing surface, the luminance can be calculated in accordance with the following formula (SANS 10114-1, 2005):

where

L is the luminance, candelas per square metre; E is the illuminance, in lux; r is the reflection factor.

For example, if a matt surface that has a reflection factor of 0.5 is exposed to an illuminance of 200 lx, the luminance is

cd/m² Illuminance is a photometric measure of the total luminous flux incident on a surface per unit area. It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with the human brightness perception. Similarly, luminous emittance is the luminous flux per unit area emitted from a surface. Luminous emittance is also known as luminous exitance.

In the SI system these are measured in lux (lx). lluminance was formerly often called brightness, but this leads to confusion with other uses of the word. “Brightness” should never be used for quantitative description, but only for nonquantitative references to physiological sensations and perceptions of light.

4. Daylight factor The daylight factor is the ratio of internal light level to external light level and is defined as:

where:

E i = illuminance due to daylight at a point on the indoors working plane.

E o = simultaneous outdoor illuminance on a horizontal plane from an unobstructed hemisphere

of overcast sky.

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There are basically three paths (daylight factor components) along which light can reach a point inside a room, i.e. through a glazed window, rooflight or aperture as follows: • The sky component (SC) that is direct light from part of the sky or sun at the point considered.

• The externally reflected component (ERC) that is light reflected from an exterior surface and then reaching the internal point measured.

• The internally reflected component (IRC) that is light entering through the window but reaching the point only after reflection from an internal surface.

The sum of the three components gives the illuminance level in lux at the point measured. The daylight factor only gives the proportion of daylight from outside that reaches the interior of the building and does not indicate the absolute level of illumination that will occur.

To calculate daylight factors requires complex repetition of calculations. It is normally undertaken by a software product such as Radiance. This is a suite of tools for performing lighting simulation which includes a renderer as well as other tools for measuring the simulated light levels. It uses ray tracing to perform all lighting calculations. The design day used for daylight factors is based upon the standard Commission Internationale de l’Eclairage (CIE) overcast sky for 21 September at 12h00 and where the ground ambient light level is 11921 lux. Since the CIE standard overcast sky assumes no orientation effects, the estimates of the daylight contribution can be wrong. To correct for this, orientation factors have been derived to be applied to the daylight factors. More recently the CIE has derived a standard based on the spatial distribution of daylight, i.e. the CIE Standard General Sky (CIE, 2002).

Rooms with a DF of 2% are considered daylit. However a room is only considered as well daylit when the DF is above 5%.

Table 6.3: Various levels of Daylight Factor

Average DF

Appearance

Energy Implications

< 2%

Room looks gloomy

Electric lighting needed most of the day.

2% to 5%

Predominantly daylit appearance, but supplementary artificial lighting is needed.

Good balance between lighting and thermal aspects.

> 5%

Room appears strongly daylit.

Daytime electric lighting rarely needed, but potential for thermal problems due to overheating in summer and heat losses in winter

Case study

The following is an example of how a designer might approach a design analysis to optimize daylight in a building. The first step is to determine the solar angles at different times of the year accurately.

With the advent of Google Earth it has become much easier to determine these accurately. This is the basis for the calculation of solar angles.

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Table 6.4: Calculation of solar angles by means of a specialized solar angle calculator (Author)

Project

Port Elizabeth Bio Composite Building

Latitude

34° 0’ 3.10” S

Longitude

25° 40’ 1.38” E

Date

Time

Azimuth

Elevation

21 Dec Sunrise

05h02

119.37°

-0.57°

21 Dec Sunset

19h28

240.68°

-0.45°

21 Dec Noon

12h15m13s

0.01°

79.43°

21 June Sunrise

07h22

62.02°

-0.55°

21 June Sunset

17h16

297.98°

-0.54°

21 June Noon

12h19m00s

0.00°

32.58°

23 Sept Sunrise

06h06

90.48°

-0.49°

23 Sept Sunset

18h14

269.31°

-0.41°

23 Sept Noon

12h09m51s

0.00°

56.02°

21 March Sunrise

06h21

90.44°

-0.41°

21 March Sunset

18h28

269.74°

-0.50°

21 March Noon

12h24m36s

0.00°

55.82°

Sunshine Time

14h25

9h53

12h08

12h07

By means of a specialized solar angle calculator (NOAA, 2011) the accurate sunrise, solar noon and sunset angles can be accurately determined for any date and time of the year. Figure 6.1 show an example of a site in Port Elizabeth at latitude of 34° 0’ 3.10” S and longitude of 25° 40’ 1.38” E. Notice that the sun rises approximately 30° south of east on summer solstice (21 December) and sets at a similar angle south of west. This implies that the southern façade receives a significant amount of solar radiation in summer.

Once the basic direct solar penetration geometry is understood, the designer can begin to explore the finer details of daylight design. It is a common mistake to assume that solar radiation consists of direct rays only. In reality a significant proportion of the solar radiation is diffuse (Holm, 1996).

It is important to note that the daylight factor comprises three components, i.e. a sky component, externally reflected and internally reflected component.

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Dulux has five pillars under the ‘Step towards greener’ approach to contribute positively to future generations as we continue to provide quality products that meet decorative needs:

PRODUCTS AND SERVICES

www.duluxtrade.co.za

THE 5 PILLAR VISIONS PRODUCTS AND SERVICES

Our products and services will create sustainable value by systematically reducing the ecological footprint of the whole-life decorating process.

PEOPLE AND COMMUNITY

Our employees will be proud to work for a company that puts sustainability at the forefront of its agenda.

We will play a positive role in the local communities.

Innovative Sustainable Solutions Dulux believes in delivering new products that tackle sustainability in an innovative way. Whether it’s lessening the carbon footprint whilst adding colour with the Dulux Trade Ecosure range, saving time and money with the Dulux Trade Weathershield Range or finding a brighter way to make a room more energy efficient with the Dulux Trade Light and Space Range, our products offer the best balance of performance and sustainability. As Silver Founding Member of the Greenbuilding Council of South Africa, Dulux Trade supports the Green Star Rating Tool.

PEOPLE AND COMMUNITY

Let’s Colour Project - Dulux recognizes the impact that colour has in our lives and encourages adding colour to people’s lives™ with an easy splash of paint, to transform grey spaces into colourful surroundings full of inspiration. The Let’s Colour Project is a worldwide initiative that is uplifting spaces in and around South Africa, as we team up with our local communities all over the world to bring bright positive change.

ENERGY

ENERGY

We develop our carbon strategy and work to build initiatives with our suppliers to reduce emissions across the business.

Dulux encourages the reduction of carbon emissions through energy reduction and renewable resources by ensuring that our energy management systems measure and reduce our carbon footprint. Our aim is to halve our CO2 emissions for our energy consumption by 2020.

TRANSPORT AND TRAVEL

TRANSPORT AND TRAVEL

We will significantly reduce the impact on people and the environment associated with the movement of our products and our people.

Dulux is committed to reducing business related travel, we encourage all employees to consider the environmental impact of their travel by introducing a business wide audio and online conferencing tool.

We continually optimize our logistics and delivery network.

WASTE AND RESOURCES

We will eliminate waste and emissions from our own operations and reduce the impact of our products and our packaging for our customers.

WASTE AND RESOURCES

At Dulux we are committed to reducing waste from our manufacturing process, our manufacturing site in Durban engaged with a recycling company to manage waste on site.

chapter 6: Optimising Daylight in South Africa: A Case Study

Figure 6.1: Solar angles for sunrise and sunset for the various seasons for a proposed building in Port Elizabeth (Author)

Once the horizontal solar angles have been determined the designer can proceed to investigate the solar penetration in section for the various critical points during the year, i.e. Summer Solstice, the equinoxes and Winter Solstice. Figure 6.2 clearly illustrates the various ways that natural daylight can arrive in a building, i.e. the sky component, externally reflected component and internally reflected component. In this case the same Port Elizabeth site illustrated in Figure 1 has been used.

Subsequent to this bespoke software such as Radiance or general software such as Ecotect can be used to gain a 3-D insight of sun and shade as well as the expected levels of illuminance, luminance and daylight factors. If it is a large and complex building a full scale mock-up can be used. A good example is the natural daylight design of the Headquarters Building for the New York Times building on Times Square in New York.

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Figure 6.2: A study to determine the solar penetration at noon for a building that uses a solar shelf for natural daylight.

Figure 6.3: Natural daylight studies for the New York Times building using a full scale mock-up. The top left image indicate the appearance at 09h30 and the bottom right at 18h15 on a particular day. (Hughes, 2006)

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Conclusions

Previous generations of architects had understood the window opening as a discrete source from which light flowed. They had channeled it, by interior light reflection and inter-reflection, to produce adequate illumination, and in this context to obtain a distinctive modeling of the interior and the objects in the interior. Paintings of the seventeenth century Dutch school, exemplified by Vermeer and de Hooch, exploited these effects (Button, 1993).

Building designers are now required to consider and optimize natural daylight design. This requires an in depth knowledge of solar movement and angles and takes effort and care as it strongly influences the energy consumption of the building and the general comfort of the occupants (Gabriël, 2009).

Many solutions and tools exist for performing natural daylight penetration analyses. Ecotect is a useful tool for less thorough daylight analyses for designers with little knowledge of detailed daylight design. This software quickly gives fast interpretable information for early design phases. However, when energy savings estimation due to daylight is the goal, Radiance should be used for more reliable results, because it supports ray-tracing techniques (Gabriël, 2009).

References

Button, D., Pye, B. 1993. Glass in Building. Butterworth Architecture.

CIE DS 011.2/E:2002. 2002. Spatial distribution of daylight - CIE standard general sky. Commission Internationale de l’Eclairage.

Conradie, D.C.U. 2011. Maximising the Sun. In The Green Building Handbook, South Africa, Volume 3. Alive2green, pp. 147-159.

Conradie, D.C.U. 2012. SA Climate Zones and Weather Files. In The Green Building Handbook, South Africa, Volume 4. Alive2green.

Gabriël, S. 2009. Integration of daylight and visual comfort by the use of an architectural design methodology for early design stages. In proceedings of the 3rd CIB International Conference on Smart and Sustainable Built Environments, June 15-19, 2009, Delft, The Netherlands.

Holm, D. 1996. Manual for Energy Conscious Design. Department of Minerals and Energy Directorate Energy for Development.

Hughes, G. 2006. The Headquarters Building for the New Tork Times. In proceedings of second national conference of IBPSA-USA (Simbuild2006, August 2-4, 2006, Cambridge, Massuchusetts.

International Energy Agency (IEA). 2000. Daylight in Buildings. A Source book on daylighting systems and components. A report of IEA SHC Task 21/ ECBCS Annex 29.

NOAA. 2011. Solar Position Calculator. National Oceanic and Atmospheric Administration (NOAA). http://www.srrb.noaa.gov/highlights/sunrise/azel.html .

Accessed 7 November 2011.

Osburn, L. 2010. Lighting. In The Green Building Handbook, South Africa, Volume 2. Alive2green. Pp. 297-306.

Rasmussen, S. 1964. Experiencing Architecture. Chapman and Hall, London.

Rubel, F., Kottek, M. 2010. Observed and projected climate shifts 1901 – 2100 depicted by world maps of the Köppen-Geiger climate classification. In Meteorologische Zeitschrift, Vol 19, No. 2, 135-141.

SANS 10114-1. 2005. South African National Standard. Interior lighting Part 1: Artificial lighting of interiors. SABS Standards Division.

SANS 204-1. 2008. South African National Standard. Energy efficiency in buildings, Part 1: General requirements. SABS Standards Division.

SANS 204-2. 2008. South African National Standard. Energy efficiency in buildings, Part 2: The application of the energy efficiency requirements for buildings with natural environmental control. SABS Standards Division.

UNEP. 2009. Greenhouse Gas Emission Baselines and Reduction Potentials from Buildings in South Africa. United Nations Environment Programme – Sustainable Buildings & Climate Initiative.

Wikipedia. 2011. Daylight factor. http://en.wikipedia.org/wiki/Daylight_factor. Accessed 10 November 2011.

(Footnotes)

1 Dalle de verre is a French term meaning slabs of glass. Artists using this medium typically use 203 x 254 x 19 coloured slabs of glass. The glass is set in fine reinforced concrete or resin. This is an interesting modern alternative for stained glass.

2 Anidolic lighting systems use non-imaging optical components such as parabolic or elliptical mirrors to capture exterior sunlight and direct it deeply into rooms while also scattering rays to avoid glare.

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PROFILE

Group Five Group Five builds Green– developing the tools Integrated construction and infrastructure development group, Group Five could be considered one of South Africa’s leading contractors in the rapidly evolving green building sector, says Grant Ramsay, Group Five Building’s senior project manager.

Group Five was the Main Contractor for two of the first five projects in South Africa to be certified

by The Green Building Council of South Africa (GBCSA) in accordance with it’s Green Star SA Rating System. The 4-star certified Nedbank Phase II project in Sandton achieved the country’s first certified ‘Design’ rating for a project as well as the first ‘As Built’ rating. In Umhlanga, Group Five recently completed the 4-star certified Shepstone Wylie project, 24 Richefond Circle.

Group Five, in association with the Green Building Council of South Africa (GBCSA), has played an instrumental role in the development of all the rating tools for Green Star SA (along with various other industry experts). Back in 2008, the GBCSA released the first Green Star SA rating tool for office buildings. Group Five was part of the working group that developed this tool. This has been followed by additional sector specific rating tools for Retail projects and Multi-Unit Residential projects, both developed with Group Five’s input.

Group Five and the GBCSA Technical Working Group are currently developing a rating tool for Public Buildings covering amongst others: libraries, convention centers, education facilities, worship facilities, courts, casinos, and airport buildings. “We were approached by the GBCSA in our capacity as expert contractors with an understanding of Green Star SA Rating Systems, and have been involved in the development of every rating tool ever since,” says Ramsay.

The Green Star SA Rating system allocates approximately 11 points to project design issues that are typically under the control of a Main Contractor. With the achievement of two certified buildings, Group Five has proven systems to drive the assembly of the documentation and the control of subcontractors and suppliers in order to complete the paper trail for a successful ‘Design’ or ‘As Built’ Green Star SA submission.

Contact Details

Grant Ramsay, Senior Project Manager, Group Five Building Cell: 082 780 7388, Tel: 011 253 8400 Email:gramsay@groupfive.co.za Website: www.groupfive.co.za

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Group Five is an exceptional provider of integrated building, infrastructure and engineering solutions

Committed to

building a better planet through eco-ingenuity Office buildings Multi-unit residential projects Public buildings The group was the main contractor for two of the first projects in South Africa to be certified by the Green Building Council of South Africa with its Green star SA rating system: The 4 star certified Nedbank Phase II project in Sandton, Gauteng, South Africa.

The 4 star certified Shepstone Wylie project in Umhlanga, KwaZulu-Natal, South Africa.

The group is investing substantially in the development of concentrated solar power plants and is supporting wind developers in realising their progress.

1 9 7 4

-

2 0 1 2

Years as a listed entity CERTIFIED BY THE CRF INSTITUTE

371 Rivonia Boulevard, Rivonia | PO Box 5016, Rivonia 2128, South Africa Tel +27 11 806 0111 | Email info@groupfive.co.za | Website www.groupfive.co.za

chapter 7: Environmentally sustainable concrete structures

Environmentally sustainable concrete structures Santie Gouws Managing Director Concrete Growth

Introduction

Concrete is the most widely used man-made material on earth and energy is consumed and CO2 emitted during its manufacture and production. The production of Portland cement results in 800-900 tonnes CO2 being emitted per ton of clinker produced. However, when considering cement and its use in concrete, it is important to realize that only about 10 to 15% of the mass of a cubic meter of concrete consists of cement. Nevertheless, although the environmental impact per cubic meter of concrete is not that high, the total effect is significant because of the large volumes produced worldwide. According to figures by Sakai6 the volume of CO2 emitted by concrete construction in 2008 alone amounted to between 10 and 20% of the total CO2 emitted world-wide. A breakdown is shown in Table 7.1.

Table 7.1. CO2 generated by concrete construction (based on Japanese practices applied to world production figures)

Although concrete contributes to CO2 emissions, it also has an important role to play with regard to infrastructure development: • Concrete is a versatile building material used for the construction of houses, schools, hospitals, roads and many other engineering structures with different sizes, shapes and structural requirements, • Concrete is a low maintenance durable construction material and is used to construct structures with service lives of up to 100 years and more, • When used correctly, it can result in more even indoor temperatures due to its high thermal mass, • When correctly designed, it has relatively high resistance to fire damage, vibrations and noise, • Concrete drainage systems can be used to manage storm water for the recycling of water and to prevent flash flooding, • At the end of life of a structure, the concrete can be crushed and recycled into e.g. road stone, and in the crushed state will reabsorb significant amounts of CO2

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When considering initiatives to reduce the carbon footprint and energy consumption associated with concrete, it is thus important to evaluate concrete and its use in structures in totality. In order to achieve a reduction of the current and future impact of concrete construction on the environment it is therefore suggested that a shift is needed: from designing structures purely for safety, serviceability and durability; to correspondingly also designing for environmental sustainability.

This will require a holistic approach that embraces and integrates all aspects from energy efficient building design to structural design of concrete elements in buildings to material selection and proportioning, production and construction methodology to transport of materials, whole life cycle maintenance, dismantling, and reuse and recycling.

The life cycle inventories for concrete structures

A life cycle inventory1 quantifies the total environmental impact, whether CO2, depletion of scarce resources, waste and harmful substances in terms of health and environment, of a building throughout its life cycle. It is therefore a useful tool used to guide the development of cleaner technologies in areas where they would give the largest environmental benefit. Cleaner technologies represent a broad spectrum of solutions aimed at reducing or improving different environmental impacts such as water consumption, hazardous substances in waste water, working environment, materials resource consumption, energy consumption etc. A holistic understanding of the environmental impact, in the life cycle of construction is then created by feeding the data into the life cycle inventories.

As such the life cycle of concrete can be described by the 5 phases shown in Figure 7.1: • Phase 1 - Extraction and processing of component raw material • Phase 2 - Concrete production • Phase 3 - Construction and re-building/extension of buildings and structures • Phase 4 - Operation and maintenance

Phase 5 - Demolition and waste treatment/recycling

Figure 7.1. Life cycle of concrete structures

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Table 7.2 gives an example of the quantification of CO2 emitted during the production and construction phases. A full inventory of the CO2 emitted during all the phases is required to compare strategies toward reducing CO2 emissions.

Table 7.2. Example of quantification of CO2 inventory during construction phase

Phase 1 – Raw materials transportation

Transportation and material processing can make out up to 10% of the CO2 emitted during phases 1-33. The raw materials for cement production, i.e. limestone, gypsum etc., need to be processed and transported to the cement plant, and similarly so the cement and aggregates for use in concrete production needs to be transported to the ready-mixed plant or construction site. The amount of material, vehicle size (a larger vehicle can carry more and will have a smaller overall impact on the environment), and distance travelled will have an influence on the amount of CO2 emitted.

When cement extenders like fly ash or slag is used in concrete to reduce the environmental impact of the concrete, the transportation distance and CO2 emitted by the fuel used over that distance would need to be balanced against the advantage obtained from using waste materials with zero carbon footprint. Another example is the transportation of limestone to the cement plant. In terms of CO2 emitted during transportation, it would be more advantageous to have the cement plant in close proximity to the limestone quarry and rather transport the cement to the market, than having the cement plant close to the market and transporting the limestone over long distances to the cement plant, the reason being that a significant percentage of the mass of the limestone is lost in the cement manufacturing process, therefore transporting limestone over long distances would result in more material being transported, and more CO2 emitted than when the finished product is transported.

Phase 2 – Production

Clinker production makes out about 60% of the CO2 emitted during phases 1 to 3. CO2 is emitted both when coal or other fuels are burnt to achieve the high temperatures needed for the clinkering process, as well as from the calcination of the limestone (CaCO3) to form Portland cement clinker.

Phase 3 – Construction

Construction makes out about 30% of the CO2 emitted during phases 1 to 3. CO2 is emitted and energy is required for mixing of the concrete as well as transporting it to site in the case of readymixed concrete, as well as for casting, installing and curing of the concrete.

Phase 4 – Use, repair and maintenance

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This phase is the main contributor to CO2 emissions by buildings and makes out between 80% and 95% of the total CO2 associated with concrete use internationally, depending on whether the building is situated in a cold or warm area. During the operation of the building, energy is used for electricity, ventilation and the heating and cooling of the building. In this respect the relatively high thermal mass of a concrete structure will play a significant role in reducing the very high levels of CO2 emitted through producing electricity to heat and cool buildings, since thermal mass influences the daily fluctuations of the temperature within the building and if this aspect of concrete is utilized correctly can result in indoor temperatures within the comfort zone.

Maintenance/repair’s environmental impact includes the CO2 emitted and the energy associated with the replacement of any part of the structure. For example, the overall environmental impact of replacing 1 out of a 100 bridges far outweighs the impact of changing the type or amount of cement used in the concrete in a bridge.

Phase 5 – Demolition and recycling

Once a structure has reached the end of its useful service life, it is demolished. Energy is consumed during demolition and for sorting and crushing the concrete for re-use. The crushed material can however be re-used either as secondary aggregate in new concrete or as sub-base or fill in road construction.

Strategies towards improvement of environmental sustainable concrete structures

Strategies associated with phase 1-3

Although fuel combustion technologies can and have been improved to reduce the energy consumption used for cement production by about 6% worldwide over the last 20 years, the predicted increase in infrastructure and as such cement demand due to economic advancement that is currently occurring in developing countries is such that a focus on reduction of CO2 emissions related to cement production alone will have limited effect.

Three ‘tools’ are therefore suggested: • Tool 1 – Reduce carbon emissions from cement through use of supplementary cementitious materials • Tool 2 – Reduce consumption of cement in concrete • Tool 3 - Reduce consumption of concrete in construction Reduce the carbon emissions from cement through use of supplementary cementitious materials (Tool 1)4 A portion of the cementitious component of concrete can be substituted by supplementary cementitious materials such as fly ash, ground granulated blast furnace slag and silica fume. These supplementary materials may enhance some properties of the concrete, but can also affect the rate of strength development. To counter this effect, the structural designer may choose to design e.g. the foundations of large buildings for 56 rather than for 28 day compressive strength, since it may be possible that foundations of large buildings are in any case only loaded to its full capacity after 56 days.

This will obviously have to be related to the construction schedule.

Consume less cement in concrete (Tool 2)4 Admixtures such as super-plasticisers can be used to reduce the water demand and as such the cement content of concrete whilst still maintaining the compressive strength. Another alternative to reduce the water demand is to increase the allowable coarse aggregate size, especially in e.g. foundations. In other elements an increase in coarse aggregate size will result in increased cover requirements which will increase the weight of the structure. the green building HANDBOOK

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Improved quality control in terms of aggregate grading and control over and measurement of aggregate moisture content will have a significant impact on reducing the degree of variability of concrete strength test results. As such the target strength of a concrete mix could be reduced, with the concomitant reduction in cement used.

Table 7.4 shows an example of employing the correct mix design principles per structural design and construction requirements for various structural elements of a bridge.

Table 7.4. Example concrete mix designs for reduced cement consumption as per Glavind

Consume less concrete in new structures (Tool 3) Internationally the use of high strength concrete has become very popular and the benefit of this is that depending on the element type, element dimensions can be reduced whilst maintaining the same load bearing capacity. Less concrete can thus be consumed in new structures by making use of high strength concrete and new designs with smaller dimensions. An additional advantage of reduced element size is the reduction in volume of concrete to be transported to site. Tools like life cycle inventories can start to quantify these advantages and identify areas with most potential.

The concrete consumption can also be reduced by designing more durable structures, which increases the service life and decreases the need for rebuilding.

Implications of use of tools 1 to 3 From table 7.5 it can be seen that if Mehtaâ&#x20AC;&#x2122;s tools were to be employed on an international scale whilst taking the increased cement demand related to increased infrastructure demand into account, a reduction in CO2 emissions of up to 40% could be achieved. This figure is shown for illustration of the principle since it will in actual fact be lower on an international scale due to the relative and regional availability of supplementary cementitious materials.

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Table 7.5. Potential implications when employing tools 1 to 3

Strategies associated with phase 4

Concrete and other heavy materials can have a positive impact on the energy consumption of buildings due to its high thermal mass. The thermal mass of such materials influences the daily temperature fluctuations within the building so that the indoor temperature is better kept within the thermal comfort zone as shown in Figure 7.2. During summer conditions concrete stores the heat during mid-day releasing it in the night time. The heat is partly solar radiation through the windows but also the free heat gains from persons, electrical equipment and so forth. Thus, high thermal mass reduces the need for cooling. This is especially beneficial to office buildings where working efficiency is influenced by the temperature level during the day time.

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Figure 7.2. The stabilising effect of thermal mass on internal building temperature

Strategies associated with phase 5

By using recycled waste products there is a reduction in the use of raw material and the need to dispose of the waste. The relevant products to reuse in concrete production are: â&#x20AC;˘ construction and demolition waste (recycled concrete aggregate) â&#x20AC;˘ washing water from washing concrete plant Recycled concrete aggregate As such recycling of the crushed concrete reduces the environmental impact by reducing the amount of virgin raw material used in the production of new concrete and therefore the CO2 emitted and energy used for its processing, and potentially also for its transport if the recycled material is used in the new construction. Care needs to be taken when recycled concrete is re-used as aggregate in new concrete since it tends to be highly porous, and increase the water demand (and cement content) of new concrete.

However, especially when used as road-stone, crushed recycled concrete reabsorbs a significant amount of the CO2 emitted during cement manufacture through a process called carbonation, which is again advantageous.

Carbon uptake Figure 7.3 shows the amount of CO2 absorbed during the life span of a concrete structure versus after demolition after a Danish example1. The red column is the total CO2 emitted during cement manufacture. These values are very significant in Denmark since in the order of 90% of demolition waste in Denmark is recycled into road construction. Since more surface area is exposed after demolition the carbon uptake is significantly increased.

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Figure 7.3. Carbon uptake of concrete

A similar trend is shown in Figure 7.4 for the carbon uptake of elements like roof tiles with a large surface area in relation to its volume.

Figure 7.4. CO2 inventory of a roof tile

Recycled wash water In the production of concrete water is both used as a concrete constituent and for washing down the plant and the equipment. The water so consumed amounts to 150-200l per cubic meter concrete and another 100 l daily for washing down ready-mixed concrete trucks, mixers and equipment. Due to the high alkalinity of the wash water, apart from the high volumes used, environmental problems will occur if it is discharged into storm water systems. This water can be recycled by installing a commercial reclaiming system. This system separates out the aggregate and coarse sand portions from waste concrete with the remaining liquid and fines going into the wash water recovery system, from where it can again be used in fresh concrete. The use of recycled wash water back into concrete is allowed for and described in SANS 51008. the green building HANDBOOK

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Conclusion

The development of sustainable concrete structures relies on a holistic approach and direct quantification of the impact over the life span of a structure. Various strategies exist to reduce the environmental footprint of concrete structures, but realistic comparisons can only be done once these are compared over the life span of a structure using quantified data as per life cycle inventories.

References

Damtoft J.S., Glavind M. & Rottig S. ‘Cleaner technology solution in the life cycle of concrete products’ Prcd’s of CANMET/ACI Int Conf San Francisco, September 2001 Gaimster R. & Munn C. ‘The role of concrete in sustainable development’ Glavind M.,Mathiesen D. & Nielsen C.V. Danish ‘Sustainable concrete structures a win-win situation for industry and society’ Metha P.K. & Meryman H. ‘Tools for reducing carbon emissions due to cement consumption’ structure magazine, p 11-15, January 2009 Nielsen C.V. ‘Carbon footprint of concrete buildings seen in the life cycle perspective’ Prcd’s NRMCA 2008 Concrete Technology Forum, June 2008, Denver Sakai K. ‘Journal of advanced concrete technology, vol 3, No 1, p 17-28, February 2005, Japan Concrete Institute Swanny R.N. ‘High performance cement based materials and holistic design for sustainability in construction (Part I)’ Swanny R.N. ‘High performance cement based materials and holistic design for sustainability in construction (Part II)’ ‘SANS 51008 Water for use in concrete’ SABS, Pretoria 2006

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PROFILE

Concrete Manufacturers Association GREEN PAVING MEANS BETTER WATER MANAGEMENT South African water resources are under increasing pressure through population growth and increasing urbanization. This means that every effort must be made to harvest our scarce rainfall in the most sustainable and environmentally-friendly manner.

One of the most affordable and effective ways in managing water in the urban environment is through permeable concrete block paving (PCBP), the green alternative to conventional paving. PCBP is a rain-drainage system in which water infiltrates through the paved surface as opposed to traditional non-permeable paved surfaces, where the water washes off into gulleys and storm-water drains.

PCBP is a form of water harvesting in which rainfall is either absorbed into the groundwater table, or through a process of attenuation, is released gradually into storm-water pipes to prevent flooding. Some systems employ a combination of the two. Alternatively, water can be stored in underground ‘tanks’ for use as a ‘grey’ water for sanitation and garden watering (see diagrams).

This inexpensive solution has been actively promoted by the Concrete Manufacturers Association (CMA) over the past four years.

CMA director, Hamish Laing, says PCBP is a deceptively simple technique which not only acts as a water-management system but also provides an attractive paved surface, indistinguishable from its impermeable counterpart.

It is extremely environmentally-friendly from every angle and is far less expensive than new or upgraded storm-water drainage,” says Laing.

“Substantial new demands have been placed on storm-water systems during the past 10 years owing to the unprecedented levels of urban development in South Africa. Every time a non-permeable or conventional paved surface is installed it places an additional burden on existing storm-water drainage and increases the likelihood of flooding.

“Flooding causes river temperatures to rise, which together with increased levels of pollutants, are prejudicial to human and aquatic life. By contrast, PCBP addresses both flooding and pollution issues, controlling the release of rain water into storm-water pipes and capturing most of the pollutants in the sub-base materials.”

The CMA promotes PCBP systems through seminars and articles and has published a detailed brochure on the subject. It also markets PermPave, software specifically aimed at

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PROFILE assisting civil engineers and landscape architects in the design of PCBP systems. PermPave includes South African rainfall data and facilitates the selection of paving blocks best suited to a particular application. Moreover, it allows water requirements and volumes to be specified, either for storage and reuse or for replenishing underground water tables.

Cape Town’s Grand Parade where a ±5 000m² strip at the bottom end of the square has been surfaced with a PCBP system.

This diagram demonstrates a PCBP system in which the water infiltrates through the paved surface infiltrates into the subgrade (ground).

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PROFILE Where the subgrade is not capable of absorbing all the water, as depicted here, outlet pipes are installed beneath the permeable sub-base to allow excess water to be drained into other drainage mechanisms such as swales, ponds, water courses or storm-water pipes.

When a permeable flexible membrane is placed on top of the sub-grade and up the sides of the permeable sub-base, as shown below, it effectively forms a storage tank.

Contact Details:

Hamish Laing (011) 805 6742 Email: bigsky@ibi.co.za Website: www.cma.org.za

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chapter 8: Waste to energy – Bio gas and Landfill gas from Anaerobic digestion

Waste to energy – Bio gas and Landfill gas from Anaerobic digestion Mauritz Lindeque Researcher Built Environment CSIR

Background

Two of the main problems that the human race is faced with are, 1) waste disposal and 2) energy generation. Energy manifests itself in many forms. This is according to what we require in order to achieve the needs and comforts of life and the quantity of energy it takes to achieve these levels of comfort. With the advent of the industrial revolution the demand for energy has increased dramatically as well as the production of waste. It has become more apparent in the past few decades that the generation of energy from fossil fuels has contributed to the net volume of carbon dioxide (CO2) and other green house gasses (GHG) in the environment, which has detrimental effects on the environment and the general well being of the planet. Furthermore the disposal of organic waste on landfill sites has increased the emissions on GHG such as Methane (CH4). CH4 is seen as a gas that has a detrimental impact on the environment by a factor of 24 times more so than CO2 (NOAA 2008).

Apart from the fact that CH4 is emitted from landfill sites (LFG) it also has the added pollution caused by leachates that seep in to the ground water from decomposing organic material on landfill sites (Surry County Council 2011). The South African Government is attempting to address these issues by concentrating on improved waste management plans and furthermore addressing the generation of renewable energies. These strategies such as the Waste Management Act No. 59 of 2008, the National Waste Management strategy 2010 as well as the Renewable Energy Feed In Tariff (REFIT) of 2009 amended 2011 are examples of the implemented changes.

Introduction

The generation of energy in whatever form that we require has allowed humans to settle in some of the most inhospitable places on the planet. The energy required to make our homes and workplaces comfortable include thermal energy as well as electrical energy. Electrical energy makes up 25% of the total energy consumed in South Africa (DME, 2000). Other sources of energy that contribute to the total energy production are from coal and liquid fuels. Coal fired power stations provide 93% of the total electricity generated in South Africa and globally will contribute to 44% of all electricity generated by 2030 (World Coal Association 2006). Coal is a fossil fuel that is seen as a major contributor to the net volume of CO2 and other GHG in the atmosphere. However it is important to sustain our industries and daily activities by using some type of fuel to generate the energy that we require. Moreover the planet cannot sustain the demand on the resources for ever. There will come a point in time where the demand for the resources will exceed the supply and availability of those resources. This is where a resource such as coal will reach a state of “peak coal”. With very insufficient data it is suggested that peak coal might be reached as soon as 2025 (Zittel & Schindler, 2007).

It is clear, that if we, the inhabitants of the planet, are to maintain the life style that we have become accustomed to due to the availability of resources, this life style will be under threat not only from the supply of the resources but also the impact that man has on the environment. Even if the impact on the environment is not a high priority it is important that we find alternatives to the decreasing resources. With a global population estimated to reach more than 8.9 billion by the time that we could be reaching the peak of our coal reserves (UN 2004) (World Bank 2011) it therefore has to become a priority that alternatives to present energy resources are investigated the green building HANDBOOK

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The waste that is generated by the same increasing population places available land under pressure.

With current practice the waste needs to be disposed of in land fill sites. Unfortunately the available land will be far removed from the areas where the waste is produced Manufacturing of products that are disposed of after use requires considerable energy and those products then stores that energy. This energy is contained in packaging and other forms. This means that there is a potential for harvesting that energy to take what previously was seen as waste and turn it in to a resource.

Resources and energy generation

The generation of thermal or electrical energy requires fuel. If waste is to be seen as a resource then it is important to understand the potential energy that is contained in the waste. This can only be done by characterizing the resource that needs to be converted in to energy and then identifying the most efficient and environmentally friendly method of converting that resource into energy.

Waste that will end up on municipal land fill sites include paper, food, garden waste, plastic, rubber, wood, glass, metal, ceramics and clay. This is a typical composition of waste on a landfill site.

Other waste streams that can be considered are the waste that is treated at Municipal Waste Water Treatment Plants (MWWTP). The waste at MWWTP is wet organic waste that is disposed of in sewers. This will include mainly human waste. It must be understood though that if the waste is to be converted to an energy source the waste act must be consulted. The Waste Management Act No. 59 of 2008 states “The processing of waste at bio gas instillations with a capacity to process in excess of five tons per day of bio-degradable waste,” will require a waste management licence (WMA 2009). The Act also states that if any person is to undertake any activity to reduce, reuse or recycle waste, that person should ensure that a) the process must use less natural resources than what it would take to dispose of the waste and b) that the activity is less harmful to the environment than conventional disposal of such waste.

Firstly, the waste streams need to be separated into organic and inorganic material and then in combustible and non-combustible material. Some organic material can be converted into electrical or thermal energy through high temperature combustion in incinerators or through the biological breakdown of organic matter in an environment void of any atmospheric oxygen. The latter process is called Anaerobic Digestion (AD). Not all material from a waste stream can be treated through a thermal process. Separating the materials will allow for the most efficient and environmentally friendly process to be employed.

Waste streams

Municipal Waste Water Treatment Plants (MWWTP) and Anaerobic Digestion (AD)

AD has been used in South Africa on a large scale since the 1930’s (Ross et al., 1992). It is a process that has proven very effective in the stabilisation of sludge treated at MWWTP. The process consists of the same four stages that organic material at land fill sites undergoes where biogas is generated as a bi product namely Hydrolysis, Acidogenesis, Acetogenesis and Methanogenesis. The process will not be complete unless all 4 stages have been completed (Fulford, D. 1998). Certain parameters can benefit the performance of the anaerobic digester if these are monitored and controlled. These parameters include Temperature, pH, mixing and the control of the organic loading rate. Failure to control these parameters could result in the failure of the digester thereby causing a reduction in the capacity of plant.

The most basic form of AD is found in large numbers in countries such as China, Vietnam, Nepal, India and other South East Asian countries.

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Figure 8.1: A Typical Lagoon Type AD

Source: Anaerobic Digesters

Figure 8.1 is an example of a basic form of creating and anaerobic environment for the bio degradation of organic matter in an agricultural application. The organic feedstock is introduced in to the lagoon that is covered with a membrane. The membrane serves the purpose of capturing and storing the gas that is produced and to prevent ingress from atmospheric air Smaller operations are available for the generation of bio gas on an agricultural basis. For the farming community the process is employed to treat and stabilise animal waste and other agricultural products.

Figure 8.2: Small scale plug flow AD

Source: Engineering news

Figure 8.2 is an example of a basic fixed dome type AD most commonly used for small scale agricultural or domestic applications in developing counties.

The bio gas produced from small scale digesters is primarily used for the generation of thermal energy. The digesters are totally reliant on atmospheric inputs. The operator is required to have some knowledge of the biological process to avoid failure of the digester. The organic loading rate is an example, since this needs to be adhered to. It is important that the digester is designed and sized to the daily requirements of the operator. the green building HANDBOOK

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chapter 8: Waste to energy – Bio gas and Landfill gas from Anaerobic digestion

If the daily loading rate exceeds the digester capacity then an over production of fatty acids will result and therefore causing the digester to turn “sour” (Fulford, 1998). If noticed in time the digester can recover. If this is however done on a regular basis then the digester could fail and then require enlargement to cope with a larger loading rate.

The Sludge Retention Time (SRT) in standard rate AD’s will be more than 40 days. This means that the daily volume of sludge requires 40 days in the digester to be stabilised and complete all four the stages.

Digesters are designed with different rates of operation in mind. Parameters that affect the rate of operation are heating and mixing as presented in Table 8.1.

Table 8.1: Rate of digester operation

Action

Rate

Sludge Retention Time (SRT)

Not mixed - Not Heated

Standard Rate

40 days

Mixed – Not Heated

Standard Rate

40 days

Mixed – Heated

High Rate

20 days

Source: Ross et al., 1992

The standard rate digester with the higher SRT will require a digester with a footprint twice that of a high rate digester with a lower SRT. Controlling the temperature in a digester requires thermal energy. The temperature ranges that typically improve the efficiency of the digester are in the mesophylic temperature range 30 ºC – 37 ºC. Setting a mesophilic temperature requires maintenance of within 2 ºC above and below the set temperature. Failure to maintain the set temperature can cause the bacteria to go into a state of dormancy (Fulford, 1998). A shorter SRT can be reached by operating the digester at a thermophilic temperature range 57 ºC - 65 ºC. This however requires thermal energy input twice that of a mesophilic temperature digester. The bacteria that operate at the thermophilic temperature range are more susceptible to temperature changes. Temperature fluctuations of more than 0.6ºC above and below the set temperature in the thermophilic range will not be conducive to efficient operation.

Anaerobic digestion (AD)

Organic material can be stabilised by operating an AD reactor where the organic material is subjected to a biological process. The produced bio gas can only be proportional to the volume of biodegradable organic material that is introduced into the digester which is dependent on the efficiency and the control of the parameters within the digester. If the parameters are not at optimum levels then the digester will not be at optimum efficiency, therefore not converting the optimum organic material to energy.

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The gas that is produced from treating organic matter through an AD process comprises of a number of gasses that is collectively called bio gas.

These gasses typically include: • Methane (CH4) 55 - 75% • Carbon Dioxide (CO2) 25 – 45% • Carbon Monoxide (CO) 0 – 0.3% • Nitrogen (N2) 1 – 5% • Hydrogen (H2) 0 – 3% • Hydrogen Sulphide (H2S) 0.1 – 0.5% • Oxygen (O2) Traces The biological activity of the AD will affect the volume of gas that is produced. This does not mean that the total volume of gas will be convertible to energy. An AD that is performing poorly may produce a large volume of gas but if basic parameters such as pH, temperature and loading rates are not controlled, then the CH4 percentage component may be lower than standard.

The gas that contains the majority of the energy that can be converted to thermal or electrical energy is CH4. Other components of bio gas such as CO2 are inert and do not contribute to the energy component of the gas. In its raw form with the total composition of gasses, bio gas can be used in less sophisticated applications. However if the gas is to be used in a commercial application then it will require that the gas be “scraped/treated or cleaned” to a standard that is close to natural gas.

Natural gas typically has a composition as presented in table 8.2 Table 8.2: Typical composition of Natural gas

Methane

CH4

Ethane

C2H6

70-90%

Propane

C3H8

Butane

C4H10

Carbon Dioxide

CO2

0-8%

Oxygen

O2

0-0.2%

Nitrogen

N2

0-5%

Hydrogen sulphide

H2S

0-5%

Rare gases

A, He, Ne, Xe

trace

0-20%

Source: www.naturalgas.org

It can be noted that two of the components of natural gas is (CH4 and CO2). There are also the two major components of bio gas. Therefore if the CO2 component from bio gas is reduced to the standards that are required for natural gas then the treated bio gas can be used in commercial applications such as heating gas or for the generation of electrical energy. The electrical energy can be generated through internal combustion engines or micro turbine generators where natural gas would be normally used as the fuel source.

Sizing an AD

The daily loading rate is established by the volume of available organic material or volatile solids that needs to be treated. This volume of available organic matter is then introduced into a digester where the size is affected by the SRT. Table 8.3 represent a basic calculation of the size of the digester that will be required for the person equivalent. This is for a digester that will operate from human waste only.

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Loading rate

Mass of feed sludge

VS % (Bio degradable Material)

X

Available digester Volume

100%

Or alternatively Size of Reactor = loading rate X HRT

Table 8.3: Sizing of the digester with potential gas production

Vessel Size

People served

Sludge daily loading rate

Potential Gas volume produced

320lt

19

15

370 lt/d

750lt

46

37

900 lt/d

1000lt

62

50

1200 lt/d

2000lt

125

100

2400 lt/d

5000lt

312

250

6100 lt/d

16500lt

1031

820

20200 lt/d

Source: CSIR

The calculations in table 8.3, is for a high rate digester that is heated and mixed. The size of the digester will effectively double if the digester is a standard rate digester that is not mixed or heated due to the increase in retention time. The volume of gas that can potentially be produced is calculated on a per person basis. These calculations are as indicated in Table 8.4 Table 8.4: Calculations to establish gas potential per person

COD/p/d = 36g/p/d 64gCOD = 1 MOL of CH4 = 6.022 x 1023 (Avagadro’s Number) 1 MOL of CH4 = 22.4l CH4 (Avagadro’s law) 36gCOD 100 64gCOD X 1 = 56.2% of 22.4l of CH4 = 12.58 l/p/d 1MOL CH4 = 890.8kJ 890.8 x 56.2% = 500.6 kJ/p/d = 130.2 watt-Hour/p/d of energy in raw gaseous form

Source: CSIR

The Chemical Oxygen Demand (COD) that is produced is the actual energy contained in the organic matter per person per day (Arceivala and Asolekar 2008). This is the component of the organic material that will be converted to CH4 with varying efficiencies dependant on the technology employed. This figure is an average that one person can produce.

Land fill gas (LFG) form Organic fraction of municipal solid waste (OFMSW)

The OFMSW is primarily organic material in the form of garden and food waste for example from supermarkets, domestic dustbins, shopping centres and restaurants. When this material is disposed of on a landfill site it will be covered by other waste material and sand. This process then effectively renders its environment free of atmospheric air, resulting in the commencement of the biological breakdown of the organic material. One of the by-products of this process is the formation of CH4 rich bio gas or landfill gas (LFG). CH4 is a basic Hydro Carbon. Hydro Carbons are well known to be flammable and can be used as a source of fuel to generate thermal as well as mechanical or electrical energy. The gas can be introduced into an internal combustion or gas turbine engine. the green building HANDBOOK

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chapter 8: Waste to energy – Bio gas and Landfill gas from Anaerobic digestion

For the full anaerobic process to be complete, there are four basic stages that the waste will have to undergo. These are: • Hydrolysis – in which complex molecules or polymers are hydrolysed to constitute monomers.

• Acidogenesis – the production of volatile acids • Acetogenesis – the production of acetate • Methanogenesis – the production of Methane (CH4) During the Hydrolysis stage liquids are formed, which can seep into the soil and contaminate the water table under the landfill site. This constitutes the main impact from landfill sites on the environment.

The creation of leachates has caused legislators both internationally and nationally to move away from land filling organic material.

In South Africa a Waste Management strategy was compiled suggesting that the disposal of organic waste on landfill should be prohibited (DEA March 2010). As stated this strategy is in keeping with international trends and policies.

LFG to energy projects

At present there are some projects in South Africa where electrical energy is generated from LFG. Most well known projects in South Africa are the projects in the EThekwini municipality. The Bisasar Road, Mariannhill and La Mercy landfill sites generating electricity from LFG (EThekwini Municipality Durban City).

LFG typically consist of 60% CH4 and 40% CO2. The gas is harvested from sinking of wells in the land fill site, extracting the gas that is produced in the anaerobic environment. The gas typically could be treated/scraped to remove some of the harmful components and then used as a source of fuel for electricity generators. The EThekwini sites generate different volumes of gas as presented in table 4.

Table 8.4: Gas production at the respective Land fill sites

Site

Gas Generation Capacity

Bisasar Rd

7,600m3/hr Estimated by 2014

Mariannhill

1,775m3/hr Estimated by 2024

La Mercy

770m3/hr

Estimated at closure 2006

Source EThekwini

The electricity generated from these sites is sold to an EThekwini Municipality.

Conversion of Bio gas or landfill gas into electrical or heat energy

The most common forms of energy that would be derived from bio gas or LFG would be thermal energy and electrical energy. The bio gas or LFG would be converted into these forms of energy with varying efficiencies.

Electrical energy.

The generation of electrical energy from bio gas or LFG can be done by introducing the gas as a source of fuel to an internal combustion/reciprocating engine or through a micro turbine generator.

However the conversion of fuel in to electrical energy is not very efficient when utilising the bio gas or LFG as a fuel.

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Heat/Thermal energy

The efficiency of an internal combustion engine in converting the fuel in to electrical energy will be maximum 42% (Caterpillar generators 2011) but on average 35 â&#x20AC;&#x201C; 40%. The rest of the energy is lost through heat that is generated in the generator engine. This heat is found in the lubricants (oil), water cooling jacket, metal parts inside the engine, through intercoolers and through the exhaust.

This thermal energy can be harvested and utilised for space heating or process heating, however, utilising the thermal energy will increase the efficiency of the project only if there is a demand for thermal energy.

Thermal recovery technology is an efficient manner in harvesting waste heat from generators.

The process is called Combined Heat and Power (CHP). The technology for the generation of electrical energy can be efficient up to 42%. This however requires a technology that demands high operating costs.

It is not advisable to operate equipment that operates at 100% efficiencies in thermal energy recovery.

This is due to the requirements of thermal energy from internal combustion engines for efficient operation. There are metal moving parts that are designed to expand with the increase in temperature.

When the parts are expanded it forms efficient seals such as the piston rings and valves.

The engines lubricating oil is designed to increase in viscosity with an increase in temperature. This increased viscosity allows the lubricating oil to flow more efficiently through the moving parts of the engine. If 100% of the thermal energy from the engine is recovered for alternative uses it will result in an engine that operates at temperatures below the design specifications. The result will be an increase in wear in the engine and a reduced life cycle with an increase in operating costs. Figure 8.3 below hi lights the areas of operation on an internal combustion engine where energy can be recovered.

Figure 8.3: Sources where energy can be harvested

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Source: Cranfield University

chapter 8: Waste to energy – Bio gas and Landfill gas from Anaerobic digestion

Gasses that could be harmful to generator equipment

In order to reduce operating costs and increase the life cycle of equipment it is important that the bio gas is rid of gaseous components that may cause damage to equipment. These components include Siloxane and Hydrogen Sulphide (H2S). Siloxane is a gas that comprises a mixture of silicone, oxygen and methane. When heated the silicone component will form abrasive deposits on equipment. H2S is a gas that is composed of Hydrogen and Sulphide. When the gas condensates it forms an acid that will cause dilution of lubricants and therefore damage to metal parts.

Sources of Siloxane in waste water. (Dewil. et al.,2005): Industry • Manufacturing of feedstock chemicals • Wastage from factories making products • Used commercial products (i.e. dry cleaning-green chemical alternative to chlorinated hydrocarbons) Home use • Washing paint brushes • Washing off excess sealants from tools • Leaching of unpolymerised siloxanes out of silicone formulations (i.e. double glazing sealants) • Long term degradation of silicones (i.e. in roof tiles) • Siloxane used as food additives • Pharmaceuticals • Deodorants, cosmetics, shampoo and conditioners • Hair sprays • Shaving creams

Figure 8.4: Siloxane deposits on process equipment

Source: nrgtekusa.com

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chapter 8: Waste to energy â&#x20AC;&#x201C; Bio gas and Landfill gas from Anaerobic digestion

Figure 8.5: Damage to Piston from Siloxane

Figure 8.6: Damage to Ball bearing from H2S

Source: Biodiesel research Facility EcoComplex NC

Source: SKF Bearings

Technology is available to remove some of the harmful elements from the bio gas or LFG. It however does raise the CAPEX and OPEX cost of the operation and might result in a fuel that costs more to produce than what it has in a monetary value to a M3 of Natural gas equivalent. The return on the investment period may be reduced though through investment in larger scale operations.

Conclusion

If international trends are followed and the waste management strategy for South Africa (DEA 2010) is put into practice then organic waste would not be disposed of on landfill sites. This would result in a decrease of the production of LFG in South Africa. The emphasis of treating the OFMSW could then shift to AD, which has been used successfully in South Africa for the treatment of human waste at MWWTP. Presently research is being executed operating Municipal ADâ&#x20AC;&#x2122;s to co-digest municipal waste and other organic wastes from agricultural and industrial waste sources. The AD process could play a major part in total waste management in the future. In the past Municipalities did not see bio gas that was produced on MWWTP as a resource to its full extent. This could change as MWWTP can potentially be the largest producers of bio gas in South Africa due to the large quantities of waste that is managed.

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If energy generated from bio gas is to be used for sustainable and reliable commercial use then it will require that the digester is operated at optimal performance. This can only be achieved if there is a basic understanding of the process and the parameters that allows for optimal performance.

The technology that allows for the conversion of the bio gas or LFG in to an energy form that would make such a project economically viable will require that the gas is treated to levels that will reduce operating costs. It is therefore important that the gas is converted into an energy form that makes the project economically viable. If electrical energy is required then it will make the project more viable when the heat energy is utilised as well.

References

Anaerobic Digesters. www.anaerobicDigesters .com (2011-12-08) Arceivala and Asolekar. Soli J Archeivala and Shyam R Asolekar for waste water treatment for pollution control and reuse. Third reprint. ISBN-13: 978-0-07062099-5, ISBN-10: 0-07-062099-7 Appalachian state University Biodiesel research Facility EcoComplex NC. Appalachian state University website for the Bio diesel research Facility EcoComplex.

Available on the net http://ecocomplex-biodiesel.blogspot.com/2010/01/siloxanes-lfg-and-algae.html#!/2010/01/siloxanes-lfg-and-algae.html (2011-1125) Caterpillar Generators 2011. Barlow world Cranfield University Centre for Energy and Resource Technology Schools of Applied Science Cranfield University UK. Workshop on Anaerobic Digestion of Waste hosted by University of Kwazulu Natal October 2011. www.cranfield .ac.uk DEA 2010. Department of Environmental Affairs Available on line http://www.sawic.org.za/documents/572.pdf (2011-11-18) DME http://www.energy.gov.za/EEE/Projects/Energy%20Efficiency%20Baseline%20Study/C_Appendix_Energy%20Balances%20and%20Efficiency%20 measures.pdf (2011-11-18) Dewil. R Energy use of biogas hampered by the presence of siloxanes. Raf Dewil, Lise Appels , Jan Baeyens. Elsevier. Science direct. Energy conversion and management 47 (2006) 1711â&#x20AC;&#x201C;1722. Available on the net. http://epics.ecn.purdue.edu/bgi/documents/fall%202009/energy%20hampered%20by%20 siloxanes.pdf Engineering news www.engineeringnews.co.za http://www.engineeringnews.co.za/article/rural-biogas-programme-could-benefit-20-000households-2008-02-01 (2011-11-15) EThekwini Municipality Durban City http://www.durban.gov.za/durban/services/cleansing/gastoelec/landfill (2011-11-18) Fulford, D. (1998). Running a Biogas Programme: A Handbook. London: Intermediate Technology Publishing. nrgtekusa.com http://nrgtekusa.com/ NOAA. National Oceanic and Atmospheric Administration. United States department of commerce. Article published 2008Available on the net. http://www. noaanews.noaa.gov/stories2008/20080423_methane.html (2011-11-25) Project Management eJournal http://www.pmworldtoday.net/BN/Feb/2010/01/LandfillGasProjectinDurbanDevelop.html?category=Fascinating%20Projects (2011-11-18) Ross, W.R., et al (1992). Anaerobic digestion of wastewater sludge: Operating guide. Water Research Commission of South Africa, Project No. 390, Publication TT55/92, Pretoria, South Africa.

Surrey County Council. Council website. Publication explaining impacts from landfill updated 1 November 2011. Available on the net. http://www.surrey.gov.uk/ sccwebsite/sccwspages.nsf/LookupWebPagesByTITLE_RTF/Landfill+sites?opendocument SKF Bearings. SKF bearing manufacturers website. Available on the net http://evolution.skf.com/zino.aspx?articleID=14893 (2011-11-25) UN world Population 2300. UN Economic and Social Affairs 2004 ST/ESA/SER.A/236 Available on the Net. www.unpopulation.org also op the net http://www. un.org/esa/population/publications/longrange2/WorldPop2300final.pdf. (2011-11-25) WMA: Waste Management Act . Government Gazette. Vol 529 Pretoria 3 July 2009 No 32368 GO9-148782-A World Bank World population growth 1750-2050. Available on the net http://www.worldbank.org/depweb/beyond/beyondco/beg_03.pdf (2011-11-18) World Coal Association. Available on the web. http://www.worldcoal.org/coal/uses-of-coal/coal-electricity/ (2011-11-28) Zittel & Schindler 2007 Energy Bulletin by the energy watch group. http://www.energybulletin.net/node/28287 (2011-11-25)

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Shorrock Automation also markets the world renowned WAGO-I/O-SYSTEM 750 used in energy management, heating, air conditioning, CCTV, lighting control or security installations. Included in the range is the WINSTA 770 Series of pluggable connectors for building installations. The WAGO-I/O-SYSTEM 750 is used in semi-distributed building automation, for example in energy management, heating, air conditioning, CCTV, lighting control or security installations. It is the smallest modular, fieldbus independent, distributed I/O system, making cost and space saving design of fieldbus nodes possible.

Integrated building automation and energy management solutions provide for significant efficiencies, maximum cost savings, reduced maintenance, unmatched reliability, and longterm sustainability. The open innovation helps building owners, integrators, and consulting engineers achieve a higher standard of green stewardship and durable performance.

Contact Details

Postnet Suite # 219, Private Bag X8, Elardus Park, 0047 Tel: (012) 345-4449 Fax: (012) 450-0312 E-mail: sales@shorrock.co.za Http://www.shorrock.co.za

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The Cement and Concrete Institute (C&CI) is a technical marketing organisation whose mission is to grow the market for concrete by providing information, as well as regulatory services to both users and decision makers in the built environment. It is recognized nationally as the impartial authority on all matters pertaining to cement and concrete.

The Institute encourages the creative and environmentally responsible application of architectural concrete and cementitious products, through supporting and promoting education, technical advice, application possibilities, related product developments, and efficient creative use of concrete in southern Africa. As such, the C&CI wishes to highlight the need for informed design strategies and specification for the construction of buildings.

The SA Green Star Rating and other similar evaluation tools such as LEED; place emphasis on the strategic design and the operational management of buildings, which emphasizes the critical energy consumption, water use and waste efficiency of buildings during its entire life cycle. Materials specification must play a critical role to reduce the embodied energy in a building; the manufacturing of which also needs to be factored in terms of measurable emissions, energy and finite material consumption. Buildings today must be constructed with a longer lifespan in mind; which emphasizes aspects of durability and retrofitting rather than demolition.

The cement and concrete industry has committed itself to responsible manufacturing.

Moreover, new research is returning exciting data on re-absorption of CO2 by hardened concrete, a process called â&#x20AC;&#x2DC;carbonationâ&#x20AC;&#x2122;. A Danish study (Kjellsen et al, 2005) reports that 50% of the volume of concrete will be carbonated in the service life period of 70 years of all buildings. This sponge effect makes concrete a more â&#x20AC;&#x2DC;greenâ&#x20AC;&#x2122; choice than previously thought.

In fact, how sustainable can a world then be without concrete?

The Cement and Concrete Institute is proud to be associated with this publication and wishes to invite readers to make use of its free technical advice; interactive website; extensive library collection and databases; publications and CPD accredited courses.

XXX DODJ PSH [B t 5FM t 10 #PY )BMGXBZ )PVTF

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DPS rev

UNIVERSITY OF FORT HARE: NEW AUDITORIA AND TEACHING COMPLEX: EAST LONDON CAMPUS Al Stratford Wintec Founder Past president of SAIA

Photo: Rob Pollock

chapter 9: UNIVERSITY OF FORT HARE: NEW AUDITORIA AND TEACHING COMPLEX: EAST LONDON CAMPUS

BACKGROUND

The historically renowned University of Fort Hare, situated in Alice, has, in recent times, focused on developing its East London campus in order to meet a demand for higher education in the city.

To this end, the forward-thinking Vice Chancellor and the University Strategic Development Team commissioned architects to produce a Strategic Development Framework Plan that addressed the integration of ‘town and gown’ underpinned by sustainability imperatives. Because the campus in East London is undergoing a rapid developmental phase, including planning to upgrade from 3 000 to 10 000 students within a few years, it became apparent that any new facility would require maximum design flexibility to accommodate various faculties as the different departments moved through the available space as it becomes available. In this context the brief for the accommodation requirements had to be generic.

The architects developed a ‘pattern language’ to regulate the design intent; this, inter alia, included; all floors to be accessible for services, all buildings to be oriented with long facades facing north, limited air conditioning for apparatus only, naturally ventilated spaces, maximised natural day lighting, locally sourced materials, light weight construction, alternative energy sources and rain water harvesting where factored into the equation.

The site available for the first new building under this regime is situated within the business zone and in this context required that all new development had to be over at least two floors of parking resulting in an 8.4 by 8.4 column grid. Unfortunately the Department of Education funding norms are not predicated on inner city development requiring an expensive parking solution; this together with other considerations severely compromised the available budget resulting in the projection of the column grid up into the teaching facility without the luxury of costly transfer beams.

DESIGN DEPARTURE POINT

The architectural context for green building initiative may be, at the one extreme, to bring to bear all the latest “green technology” or at the other end of the scale, to look backwards to the era before we powered up buildings. In vernacular architecture the building envelope, spaces and structure all contribute to the green agenda by the building in itself being the artefact that regulates light, ventilation and temperature, all of this within an efficient cost effective building technology that is not imported from the far regions of the world. In this context, the vernacular precedent became the overriding constraint. Appropriate orientation and high floor to ceiling heights allowing tall windows with low and high level venting together with single banked planning and court yard breathing spaces were the hallmark of good education facilities.

The other main consideration was the exact position of the building geographically and climatically both at the macro and micro level. The site is located some 200 metres from the East London Harbour on a southern slope within the old two to three storey cityscape, and the climatic response had to recognise the unique attributes of this region. At the macro level, East London is situated on the the green building HANDBOOK

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South East coast of South Africa where the climate is more sub tropical but often influenced by winter cold fronts emanating from the south west and summer humid winds from the opposite direction.

However, some of the highest temperatures are experienced during mid winter when the off shore ‘berg wind’ condition brings hot air compressed by the drop from the escarpment in the hinterland to the north. Ninety percent of the temperature range across the year is within 10 to 30 degree C with the diurnal variation being very little at about 5 degree C. In a tropical climate thermal mass becomes a real liability with little opportunity to cool the structure overnight. At the micro level, the proximity to the harbour gives little protection from the salt laden south westerly winds; fortunately, the surrounding buildings are low profile which allowed a taller structure to capture the wind energy.

It was decided right out the outset, all things being considered, that wind and solar energy may be harnessed to drive the ventilation system. The challenge of managing daylight without heating the interior and opening windows without flooding the teaching space with city noise became constraining guides to innovative solutions.

DESIGN PROCESS

Traditionally within the South African context, the professional design team has been appointed as stand alone practitioners each within their own narrow discipline where the Architect assumes the lead role in “shaping” the building conceptually followed by often abrasive correction from the engineers, structural, mechanical, electrical etc. resulting in big time consuming iterations. Using Building Information Modelling technology it is now possible to compact the design process by integrating the disparate disciplines in a small bite iterative process between practitioners.

Architect

At the outset, Al Stratford, the design architect, with extensive experience in structural engineering, industrial design, product development and innovation and who had recently also visited the acclaimed CH2 building in Melbourne Australia, envisioned a cross-sectional building typology that, together with a patented concrete floor technology, would be able to provide a design solution for the new project. At a very early stage the architectural team built a 1:10 large scale three storey high model too empirically test the proposed ventilation system and be a visual tool for the client and professional team to rally around. The day came when this model was placed in the garden facing in the right direction and tested using artificial smoke to track air movement and fans to simulate wind.

The lessons learnt here were brought to bear on a revised ventilated façade using pre-cast concrete trombe wall elements.

Mechanical Engineering

The mechanical engineers, who are used to simply calculating heat loads and specifying the corresponding mechanical hardware, had to face a “back to school” challenge. It was decided by the client to accept a recommendation from the M & E engineers to appoint the CSIR to simulate the building performance using computational fluid dynamics (CFD) modelling as sub-consultants to the M & E team. This in itself brought on further challenges to all concerned; not in the least the compatibility of software platforms and chains of communication but also the delays in decision making affecting the design programme and time line. The question of professional liability for performance of the proposed passive design solution was also brought sharply into focus resulting in the M & E Engineers formally absolving them from such liability during the process despite having CSIR to support their work.

Structural Engineering

The resolution of the pre-cast structural floor system was greatly enhanced by the prior work that had been done by the engineers with Wintec in the development of the Windeck® flooring system.

The system was scaled up to span the 8.4 m three bay parking grid with full 5 kN/m2 institutional 158

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Figure 9.1: Detailed Sectional Perspective

loading and further enhanced to receive pre-cast concrete ceiling tiles to allow access to the floor plate plenum; but more importantly to act as a conductive heat sink allowing rising heat to bleed off into the ventilated plenum space. U-shaped in cross-section, pre-cast concrete primary beams were designed to span over the column heads with in-situ concrete backfill and rebar: these beams were slotted to allow drop in secondary beams at 600 mm centres to be placed as floor joists to receive the floor and ceiling tiles. The engineering challenge was to design these secondary beams with 230 mm diameter holes at 300 mm centres all within a beam depth of 450 mm and a width tapering from 120 mm down to 100 mm at the beam soffit.

The design of the ventilated façade was predicated upon an approach that would integrate penetration of daylight and the collecting of solar energy to augment upward buoyancy of the air and insulate the interior space from solar heat gain. The structural pre-cast concrete U-shaped flues became the vertical mullions to which the flushed glazed external façade was bonded in the vertical direction with horizontal steel box sections as transoms. This system had to withstand wind forces of 1 kN/m².

Quantity Surveying

The Quantity Surveyor (QS) played a pivotal role in the design process. The need to protect the budget from the potential extra cost of innovative ideas was noted, once again, from design inception. An early cost comparison of the proposed floor system on an “apples with apples” basis was compared with an in-situ cast floor and a hollow core pre-cast system both with a superimposed access floor and suspended ceiling below to, as best as possible, match the Wintec Ventilated Access floor and ceiling system. This cost comparison indicated a 22 % saving over conventional in-situ concrete and 12 % of the alternative hollow core approach before factoring in the reduction in floor-to-floor height and the substantial reduction in building mass with the knock-on cost reduction of column and base sizes. the green building HANDBOOK

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Figure 9.2:

Photo: ESP Photograph

PROJECT PROCUREMENT AND IMPLIMENTATION

Selecting a contractor with the appropriate discipline and expertise to build the project was accomplished by preparing a detailed Power Point presentation that demonstrated in 3D graphic images the proposed production and assembly process. An open invitation was given to contractors to attend this presentation before the pre-selection tender was published. In this way those that tendered were apprised of the whole process before tendering.

Pre-cast Concrete

Without an early start to the pre-cast project, Al Stratford stepped out of his architect role directly into preparing his company Wintec Innovation (Pty) Limited to be able to price on the work and gear up to produce the new components from scratch. This entailed designing and building a production facility comprising dedicated gang moulds for about 1 000 precast beams of various configurations and lengths and over 22 000 floor and ceiling tiles of varying specification. 450 pre-cast trombe wall units also had to be produced. The concomitant concrete batching plant and infrastructure was also set up at the same time. As a parallel action engineering load bearing tests were conducted to establish the performance of the secondary beams which fell outside of existing engineering design codes.

The Main Contract

Grinaker LTA, which later became Aveng Grinaker LTA, was appointed as the main contractor. In short order they set about managing an intense process of construction and assembly against a backdrop of the usual inclement weather and also a month of industrial action. Using laser technology and having a full time surveyor on site during erection ensured accurate positioning of columns and positioning of pre-cast concrete elements. With the aid of on-site ingenuity and dedication, even producing devices and gadgets to speed up production, the building was successfully turned out to meet the design intent.

The Vertical Vegetated Faรงade

A vertical garden spanning between floors on the south faรงade was designed as a green filter to condition the incoming air. Indigenous creepers that were able to grow in shaded coastal conditions were selected and a simulated test site was established nearby in order to monitor growth and water demand during the construction period. This green screen modifies the oxygen and moisture content of the incoming air as well as capturing airborne dust particles which are washed down by the sprinkler system. Rainwater harvesting is achieved by placing six 10 000 litre tanks expressed along the south street boundary demonstrating their intent to the public. Water from these tanks is pumped into header tanks in the roof space and gravity fed to the planted faรงade and also used for flushing of the toilets. All the plants were grown off site in a nursery then planted into timber planter boxes which were brought to site at the end of the project for installation and suspension form a vertical wire mesh screen suspended between floors. the green building HANDBOOK

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DESIGN RESPONSE

In planning the complex is bounded on the north and south sides by wide streets; the primary response was to place three wings running east west, in downward cascade from the south towards the north allowing solar exposure to each wing reducing the winter shadow. Each wing is in turn penetrated by a pedestrian concourse which is vertically connected by a lift in the south wing and a series of double acting staircases at the intersection of each wing. This concourse starts on the street at parking level on the south side and spills out onto the street at second floor which is at grade on the north street. In this way the concourse becomes a pedestrian arcade of the city.

In section, the wings are single banked with pedestrian access along the south façade and teaching space lit and cross ventilated to the north. The structural floor system is cantilevered to both the north and south off the 8.4 meters column grid to provide a typical wing of 13.2 meters in overall width with a space of 3.6 meters between the buildings and 6 meters between internal spaces. The section also informs the ventilation system. The external façade to the south walkway is faced with a permeable mesh screen which serves to break wind and driving rain. Immediately inside of this screen there is a vertical planting screen with timber planter boxes at each floor which are irrigated with harvested rainwater; this serves to provide evaporative cooling and oxygenated fresh air which is drawn into the building from the cooler side of the building – it also provides a ‘handrail’ to the walkway. Air is then drawn into the Wintec Ventilated Access Floor through special floor mounted diffusers by virtue of displacement ventilation within the interior space.

The north façade is double skinned and is ventilated at the roof apex. This façade is made up of U-shaped (in plan) black pre-cast concrete panels glazed across the ‘U’ to form a vertical flu. This combination alternates with an internal glazed timber façade which is opposite a flush glazed façade spanning between the pre-cast panels. In this way another vertical flu is formed between the two glazed facades. In addition, the internal reveal of the pre-cast panels is splayed and painted white; this together with a vertical reflective Venetian blind within the flu space controls bounced light into the interior. The ventilation system is powered by solar energy through buoyancy induced in the ventilated stack façade and also by wind induced pressure differences generated at the aerofoil section covering the continuous apex roof slot.

The ventilated access floor is a new concept which provides a floor plate with access from top and bottom, a plenum for services and ventilation, all within a structural depth of 525 mm. The floor is finished on both faces with pre-cast concrete floor/ceiling tiles which provide a heat sink and are fitted with service access points for power and lighting. The total mass of this floor is 47% less than an equivalent in-situ access floor which would be about 850 mm deep. In this way the embodied energy is dramatically reduced by bringing less material to site and the floor may be deconstructed and built into another project at the end of the building life cycle.

The choice of laminated saligna for all joinery was informed by the need to not import exotic hardwoods or aluminium extrusions. This timber is locally sourced and after lamination is still cheaper than Meranti.

LESSONS LEARNT

From the perspective of the design team the commitment to use BIM at inception needed a far more integrated approach to design development. Engineers typically wait for the architects to design the whole building then drill down to final calculated structural design configurations and sizes: with BIM these activities should be done on a parallel course so that the digital building model is built together. This integrated approach has to become the modus operandi if we want to build

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efficiently into the future. Having said this, the question of professional responsibility between the different disciplines needs to be interrogated pointing towards a breaking down of inter-discipline silo thinking. An over emphasis on specialisation within the built environment professional design context has impoverished the whole.

From the client perspective the need to â&#x20AC;&#x153;go greenâ&#x20AC;? is now increasingly recognised: however, the procurement of the professional team and specialist expertise has to be redefined. In South Africa, government bodies have become consumed with the potential for corruption through procurement and rightly so. Unfortunately the ability to see opportunity for efficient and cost competitive innovation is smoke screened by these fears.

The work done by CSIR in evaluating the holistic design intent through BIM and CFD modelling was invaluable in giving a degree of comfort to the client and the design team as to the theoretical performance of the building. Unfortunately due to many reasons on the learning curve the information was after the fact resulting in a build up of understandable tension within the design team. From initial albeit limited on site measurement the practical performance appears to follow the theoretical.

However, if all are to benefit from this major exercise a comprehensive post-construction evaluation of the building needs to be done by CSIR and to enable the CSIR to transfer their knowledge and expertise to others.

From the construction perspective the decision to build, using in the main, modular prefabricated components, also needs a paradigm shift. Once again, an integrated approach should bring on board the building contractor to participate in building process engineering. The entrenched idea that we can build roughly and then cover up the roughness with finishes does not wash when buildings are assembled.

IN CONCLUSION

From inception to the present, this project has been highly inspirational (and somewhat daunting) to all involved. Working outside of the box especially in the construction industry is not generally recommended; one would be lauded for innovation in the Information Technology (IT) world far easier! We commend all those involved for commitment and staying with the agenda throughout the process.

After all is said and done, we need to have pushes of exploration into the construction industry if we are to in any way to address the imperatives facing global sustainability The University of Fort Hare, in keeping with its tradition, has not been afraid to embrace the sustainability issue in order to demonstrate its commitment to progress.

Professional Team.

Architects and Principal Agents:

Consulting Civil / Structural Engineers: Consulting Mech. / Electrical Engineers: Quantity Surveyors:

Ngonyama Okpanum Associates In association with Native Architecture HSC Consulting Carifro Consulting Engineers Pulana Baxter and Associates

Main Contractor: Pre-cast Specialist:

Aveng Grinaker LTA Building Cape Wintec Innovation (Pty) Ltd

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PROFILE

CLAYBRICK Lifecycle Key To Sustainable Building Authored by: Peter Kidger

In today’s commercial world, a positive balance of the sustainable benefits of a product in application is required over the non sustainable inputs during manufacture to fulfil the economic, social and environmental dimensions of sustainability.

With clay brick, the sustainable value afforded by its performance in application well outweighs the non-sustainable input ‘costs’, thus endorsing this environmentally friendly building material as a major contributor to the sustainable built and natural environments of the future.

Clay brick’s sustainability attributes that reduce the environmental impact of the input costs to create a more favourable balance, include: •

•

• • •

• • • •

•

•

Durability and longevity qualities to perform beyond 100 years, thus affording the opportunity to dissipate all of its embodied energy over its lifecycle, and eliminating the carbon debt associated with the replacement of less durable walling materials.

Scientific research confirming the inorganic qualities of fired clay fulfil all the essential requirements for healthy living : Its mineral content guarantees an almost pollution free indoor air quality It absorbs and releases humidity from the atmosphere providing a good moisture balance indoors It is not a food source for mould, recognised as a major cause of ‘sick building syndrome’ and being a dry material offers protection against mould growth It is a material that affords high acoustic insulation It is an incombustible material and being benign releases no toxic fumes under fire conditions As a maintenance free face brick it incurs no new carbon debt associated with a lifetime of upkeep.

It is both reusable and recyclable. Should clay brick be required as landfill it is akin to returning back to earth from where it came.

As a face brick that offers colourfast aesthetics, natural hues and organic textures, clay bricks blend unobtrusively into any natural environment.

Clay brick is a user friendly material with an endearing human scale that offers virtually unrestricted flexibility for creativity and is adaptable to a multitude of design styles and evolving trends.

Clay bricks feature natural thermal performance properties to support interior thermal comfort for longer, and contribute significantly towards optimal energy efficiency and lowest total energy [embodied and operational] over the lifecycle of residential buildings, within South Africa’s six major climatic zones.

This is validated by numerous scientific studies, including:

The Energetics Australia, Full Lifecycle Assessment (LCA) of the total embodied and operational energy used in two house types, in three locations and in four orientations using five different walling systems, found that no matter the construction type, the embodied energy of the houses comprises of less than 10% of the total energy used over a 50 year lifecycle. Of the 90% operational energy, 40% was consumed in heating and cooling to achieve target thermal comfort conditions, thus emphasising the importance of reducing energy consumption through thermally efficient building envelopes.

Other studies have also established that double-skin clay brick walls with the appropriate level of resistance between the brick skins provided for lowest cooling and heating energy usage when compared to lightweight walling that relied on a high R-value alone to achieve energy efficiency.

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PROFILE

The Energetics study concluded that ‘it makes sense to build quality houses that are durable such that the inevitable energy used in the construction is not wasted because the house remains in use beyond 50 years’. Clay brick fulfils that role admirably. All major studies also recognised that: • Achieving optimal thermal efficiency over the buildings life begins with the application of sound passive solar design techniques involving correct orientation, shading and ventilation coupled with the use of thermal mass in the buildings envelope.

•

Thermal mass is particularly relevant in South Africa’s climates, which are characterised by long hot summers where the challenge of walling materials is to moderate external temperature amplitudes to bearable levels indoors, whilst also ensuring that the average indoor temperature remains at an acceptable level throughout the year.

More recent research in respect of the CR Product of walling envelopes and energy efficiency of houses has determined that the optimal walling system will have sufficient levels of “C” (thermal capacity as derived from thermal mass) and be supplemented with appropriate levels of “R” as provided by the air in the cavity or insulation in the brickwork or both. Generally, the higher the CR Product of a walling system, the greater level of thermal comfort experienced throughout the seasons. Clay brick walls can be specified and built to offer CR values appropriate for achieving lowest lifecycle energy usage outcomes cost effectively.

Where inadequate “C” is provided, as with insulated lightweight walling envelopes, there is little or no propensity for the wall to self-regulate and thermal modelling shows how such walls cause a “hot box” effect inside during the summer months resulting in the greatest thermal discomfort and highest cooling energy usage.

Clay brick, on the other hand is a tried and trusted building material, and proven to be more relevant than ever for addressing the sustainability imperatives of today. It has no peers when it comes to structural integrity, enduring colourfast aesthetics, virtually limitless design, application flexibility and a basket of comprehensive performance attributes for supporting both lowest energy usage and healthy living. Clay brick is indeed a holistically sustainable building material ~ for good.

Contact Details Tel: 011 8054206

www.claybrick.org.za

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PROFILE

The Energetics study concluded that ‘it makes sense to build quality houses that are durable such that the inevitable energy used in the construction is not wasted because the house remains in use beyond 50 years’. Clay brick fulfils that role admirably. All major studies also recognised that: • Achieving optimal thermal efficiency over the buildings life begins with the application of sound passive solar design techniques involving correct orientation, shading and ventilation coupled with the use of thermal mass in the buildings envelope.

•

Thermal mass is particularly relevant in South Africa’s climates, which are characterised by long hot summers where the challenge of walling materials is to moderate external temperature amplitudes to bearable levels indoors, whilst also ensuring that the average indoor temperature remains at an acceptable level throughout the year.

More recent research in respect of the CR Product of walling envelopes and energy efficiency of houses has determined that the optimal walling system will have sufficient levels of “C” (thermal capacity as derived from thermal mass) and be supplemented with appropriate levels of “R” as provided by the air in the cavity or insulation in the brickwork or both. Generally, the higher the CR Product of a walling system, the greater level of thermal comfort experienced throughout the seasons. Clay brick walls can be specified and built to offer CR values appropriate for achieving lowest lifecycle energy usage outcomes cost effectively.

Where inadequate “C” is provided, as with insulated lightweight walling envelopes, there is little or no propensity for the wall to self-regulate and thermal modelling shows how such walls cause a “hot box” effect inside during the summer months resulting in the greatest thermal discomfort and highest cooling energy usage.

Clay brick, on the other hand is a tried and trusted building material, and proven to be more relevant than ever for addressing the sustainability imperatives of today. It has no peers when it comes to structural integrity, enduring colourfast aesthetics, virtually limitless design, application flexibility and a basket of comprehensive performance attributes for supporting both lowest energy usage and healthy living. Clay brick is indeed a holistically sustainable building material ~ for good.

Contact Details Tel: 011 8054206

www.claybrick.org.za

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chapter 10: SANS 10400:-XA 2001: Application of the National Building Regulations Part XA

SANS 10400:-XA 2001: Application of the National Building Regulations Part XA: Energy Efficiency in Buildings / Renewable energy Wim Jonke Klunne Senior Researcher Renewable Energy CSIR

The new SANS 10400 standards introduced requirements for the integration of non-electrical water heating in the building code. This chapter will look at the use of solar water heaters to produce (domestic) hot water.

The SANS 10400 standards stipulate that “at least 50 % (volume fraction) volume of the annual average hot water heating requirement shall be provided by means other than electrical resistance heating, including but not limited to solar heating, heat pumps, and heat recovery from other systems or processes”. This requirement forces anyone erecting a new building to have a close look at the hot water requirements of the building.

Hot water heating requirements

SANS 10400 does refer to tables 2 and 5 of SANS 10252-1:2004 to determine the total hot water requirements of a building. The first table does give an overview of the average water consumption (hot and cold) of appliances, while the second does focus on hot water requirements only. In combination with the usage pattern of the building a total hot water requirement can be determined.

The tables are reproduced here as Table 10.1 and Table 10.2 respectively.

For households the guidance given by Tudor Jones in the SA Plumbers’ Handbook (Tudor Jones, 2004) can be used. He comes to an average household consumption of approximately 300 litres / day for a four persons’ household.

Basic principles of solar water heating

Solar water heaters do come in wide variety of types and models. The most basic solar water heater is a piece of black plastic pipe or black plastic bag, filled with water, and laid in the sun for the water to heat up.

In general a solar water heater will consist of the two following components: 1. An absorber, or collector that is an energy conversion device that absorbs the solar radiation and transfers it to the fluid that passes through it. In the example of the black plastic bag, the bag is the collector and the water in the bag is the working fluid.

2. A storage tank to store the heated water, commonly made of steel with a protective inner layer, stainless steel or a polymer. Like with standard electrical geysers these storage tanks come in standard sizes and are sized in relation to the hot water demand, storage required and size of collectors used.

The working fluid used can be cycled through the tank several times to raise the heat of the fluid to the required temperature.

There are two common simple configurations for such a system: 1. The thermosyphon system makes use of the natural tendency of hot water to rise above cold the green building HANDBOOK

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water The tank in such a system is always placed above the top of the collector and as water is heated in the collector it rises and is replaced by cold water from the bottom of the tank. This cycle will continue until the temperature of the water in the tank is equal to that of the collector. A one-way valve is usually fitted in the system to prevent the reverse occurring at night when the temperature drops. As hot water is drawn off for use, fresh cold water is fed into the system from the main water supply.

2. Pumped solar water heaters use a pumping device to drive the water through the collector. The advantage of this system is that the storage tank can be sited below the collector. The disadvantage of course is that electricity is required to drive the pump.

Typically, solar water heaters in South Africa are equipped with a back-up electrical element that is controlled through a timer1 and thermostat to provide auxiliary heating during days with limited solar radiation or when all hot water has been consumed. Due to the inclusion of the heating element, electricity savings for hot water production will not be 100% of electricity consumption, but depending on the usage pattern between 50 â&#x20AC;&#x201C; 90%.

Norms and standards

The use of solar water heaters and their testing is governed through a number of SANS standards, which look into the solar water heater as a system and how they should be integrated into a building.

Table 10.3 given an overview of the applicable standards.

Herewith it should be noted that in South Africa solar water heaters are tested and certified on a systems level, i.e. a SABS mark does apply to a combination of collector(s) and storage tank.

Types of Solar Water Heaters

From the basic black pipe or bag, solar water heaters have developed into a number of distinct different types related to the way water is being heated and the type of collector being used.

Direct versus indirect systems

Direct solar water heaters circulate the water directly from the storage tank through the collector. As water is being used in the collector, direct systems are very vulnerable to overnight frost conditions that can freeze the collector and associated pipes, resulting in bursts. Although limited frost protection can be achieved through drain back valves that drain the system in case of frost, direct systems should only be used in frost-free areas. Also the quality of the water being used in the system should be monitored closely as scaling by hard water can clog the system.

Indirect, or closed systems, utilise a heat transfer fluid in the primary circuit of the collectors and a heat exchanger to transfer heat from the collector circuit to water in the storage tank. Indirect systems can be used under all circumstances as they only use the heat transfer fluid in the collector and not the potable water. Flat plate collectors are therefore popular in areas subject to extended freezing temperatures and in areas with hard water.

Flat plate versus vacuum tube collectors

The collector used to convert the solar radiation into heated water can be grouped in two distinctive categories: 1. Flat plate collectors consisting of a dark flat absorber of solar energy covered by a transparent cover that allows solar energy to pass through but reduces heat losses. The absorber consists of a thin absorber sheet often backed by a grid or coil of fluid tubing placed in an insulated casing with a glass or polycarbonate cover. See Figure 10.2.

1 A timer is mandatory when the solar water heater is installed under the DSM programme of ESKOM to avoid electricity usage during peak times

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1. Vacuum tube collectors use heat pipes for their core instead of passing liquid directly through them. Evacuated heat pipe tubes are composed of multiple evacuated glass tubes each containing an absorber plate fused to a heat pipe. The heat from the hot end of the heat pipes is transferred to the transfer fluid. See Figure 10.3.

The debate on whether vacuum tubes or flat plat collectors are the preferred option is an ongoing debate in the industry, without a very clear answer as local circumstances can influence the comparison considerably. The flat plate has the advantage of having stood the test of time – it is a mature technology and has benefitted from years of improvements. On the other hand, evacuated tubes perform better when the ambient temperature is low (e.g. during winter) or when the sky is overcast for long periods.

In general it can be said that performance of collectors decrease as the temperature differential increases (difference between ambient and collector inlet temperatures). Flat plate collectors start out with a higher efficiency, but once ambient temperatures drop to close to freezing point a cross over takes place and vacuum tubes become more efficient due to the reduced radiation losses, which is important in cold temperatures, but is not a factor in a South African climate. Several research studies have been done on this topic and the cross over point on efficiency gain of the one type over the other is depending on solar radiation, type of collectors used, etc.

It is important to note that flat plate collectors will raise water temperature to 60°C at a faster rate than vacuum tubes, after this point flat plates will slow as their efficiency drops. This in and of itself is an advantage as it limits the system’s ability to overheat, which will lead to water wastage and system damage.

Flat Plates

Vacuum Tubes

Advantages • Long life expectancy • High efficiency in sunny to moderate climates • Suitable for domestic and industrial applications • Freeze protection is available • Long and proven track record in SA conditions • Robust / hard wearing • Less strain on the primary circuit pipe field • Glycol in the collector loop has a longer service life • More resistant to hail than vacuum tubes Disadvantages • Performance reduced in freezing conditions and at low light levels • Larger roof area required in large scale systems • Greater single lifting weight during installation

Advantages • Useful where orientation to north is a problem • Perform efficiently in very cold climates • Suitable for high heat and steam generation in industrial applications Disadvantages • Limited local track record • Less robust and susceptible to hail damage • Good quality tubes are more expensive / longer pay backs • Greater overheating potential in warm climates • High stagnation temperatures with corresponding demands on all the materials within the collector field including the solar fluid • Safety valves and expansion vessels are required to deal with overheating more frequently • Risk of reduced efficiency over time as vacuum could disappear

Heat pumps as an alternative

SANS 10400 offers the option to use any other technology than electrical resistance heaters. Besides solar water heaters, heat pumps are becoming a viable alternative for hot water requirements.

Heat pumps use the reverse cycle of a refrigeration plant to heat water. In effect, it transfers heat from a source such as air or water to the water which is to be heated. As in other refrigeration equipment, the heat pump system employs an evaporator, a compressor, a condenser, refrigerant gas, and an expansion valve within a closed circuit. Latent heat is given off when the refrigerant gas is liquefied through the condenser and transferred to the surrounding water together with further “sensible” heat loss, effectively raising the temperature of water to a higher temperature.

Heat pumps can operate independently from the ambient circumstances, but do require electricity to operate. They are able to reduce electricity consumption for hot water production, but cannot, contrary to solar water heaters, eliminate the use of electricity., like solar water heaters can. the green building HANDBOOK

169

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chapter 10: SANS 10400:-XA 2001: Application of the National Building Regulations Part XA

Conclusions

Solar water heaters are a viable alternative to electric resistance water heating, with different technical options. Systems can be installed on north facing roofs with the storage vessel either above the collectors (thermosyphon systems), or hidden inside the roof when a pumped system is used.

If placing solar collectors on the roof is not feasible or not desired, heat pumps can be used instead.

Figure 10.1 Representation of the thermosyphon principle. Water can be taken out of the system at 1, while 2 represents the hot water storage tank which is filled with hot water from the collector (4) at inlet 3, while new, cold water is introduced at 5.

Figure 10.2 Schematic view of a flat plate collector

Figure 10.3 Schematic view of evacuated tubes

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Table 10.1 Average water consumption (hot and cold) of appliances (table 2 of SANS 10252-1:2004)

Domestic and commercial appliances L/operation Bath

80 – 90

Bidet

6–8

Clothes washing machine

60 – 180

Dishwashing machine

3 – 70

Domestic waste disposal unit

10 – 15 (per minute)

Shower

3 – 6 (per minute)

Wash-hand basin

4–8

WC flushing valve (normal flush)

8 – 10

Domestic appliances L/day/person served Car washing and garden use

3–6

Drinking, food preparation and cooking

18 – 22

Laundry

10 – 15

Personal washing and bathing

20 – 30

Washing dishes

8 – 12

WC flushing

32 – 40

Office installation appliances L/day/person served Hand washing: normal taps

8 – 15

Hand washing: spray taps

3–7

Urinal flushing - 24 h day

10 – 18

Urinal flushing - 8 h day

4–6

WC flushing - no urinals provided

12 – 18

WC flushing - urinals provided

4–6

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Table 10.2 Hot water demand, storage and heater power requirements (table 5 of SANS 10252-1:2004)

Premises

Total hot water demand

Storage volume at 60 °C

Heater powera

Day school

(10-12) L/capita/d

(5-6) L/capita

0,1 kW/capita

Boarding schoolb

(50-115) L/capita/d

(25-50) L/capita

0,5-0,8 kW/capita

Low rental

(80-115) L/capita/d

(100-150) L/unit

2-3 kW/unit

Medium to high rental

(115-140) L/capita/d

(40-50) L/capita

2-5 kW/unit

Staff

(10-20) L/capita/d

(5-7) L/capita/d

0,1 kW/capita

Ablutions

(30-60) L/capita/d

(30-60) L/capita/d

1,5-2 kW/capita

Low rental

(65-75) L/capita/d

(20-25) L/capita

2-3 kW/unit

Medium to high rental

(115-140) L/capita/d

(25-35) L/capita

2-5 kW/unit

General

(130-140) L/bed/d

(25-30) L/bed/d

1-1,5 kW/bed

Clinics

(120-150) L/bed/d

(30-35) L/bed/d

1,5 kW/bed/d

Infectious

(220-230) L/bed/d

(40-50) L/bed/d

1,5-2 kW/capita

Infirmaries

(65-75) L/capita/d

(20-25) L/capita/d

0,9-1,2 kW/capita/d

Infirmaries with laundry

(85-95) L/capita/d

(25-30) L/capita/d

1-1,4 kW/capita/d

Maternity

(220-230) L/bed/d

(30-35) L/bed/d

1,5-2 kW/bed

Mental

(85-95) L/capita/d

(20-25) L/capita/d

1-1,4 kW/capita/d

Nursesâ&#x20AC;&#x2122; homes

(120-130) L/capita/d

(40-50) L/capita/d

1-1,5 kW/bed

Hostels

(80-120) L/capita/d

(30-35) L/capita/d

0,8-1,1 kW/capita/d

Hotels (with resident staff)

(120-140) L/bed/d

(50-70) L/bed/d

0,9-1,2 kW/bed

Hotels (without resident staff)

(100-120) L/bed/d

(40-60) L/bed/d

0,8-1,1 kW/bed

(5-7) L/meal

(5-6) L/meal

0,1 kW/meal

Offices with canteens

(25-28) L/capita/d

(20-25) L/capita/d

0,5 kW/capita

Offices without canteens

(10-12) L/capita/d

(5-7) L/capita/d

0,1 kW/capita

Shops (staff only)

(10-12) L/capita/d

(5-6) L/capita

0,1 kW/capita

Sports pavilions(participants only)

(30-40) L/capita/d

(30-40) L/capita/d

1,5-2 kW/capita

Colleges and schools

Dwelling housesc

Factories

Flats (blocks)

Hospitals

Hotels

Kitchens Full meal preparation Offices

a Refers to direct electrical heating elements only. b Excluding kitchen but including laundry. c Storage normally a minimum of 115 L with a 4 h heat-up period.

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Table 10.3 SANS standards applicable to solar water heaters

SANS standard

Area of coverage

SANS 10106

Covers requirements for the installation, maintenance and repair of solar water heating systems for domestic use.

Excludes the installation of solar water heaters for swimming pools and commercial buildings.

SANS 1307

Specifies the requirements of domestic solar water heating systems. Does not apply to solar water heaters for swimming pools or to industrial and commercial solar water heaters, or to push-through type domestic solar water heaters.

SANS 6210

Specifies test methods for the mechanical qualification of domestic solar water heaters.

SANS 6211-1

Describes an outdoor test method for the determination of the thermal performance of domestic solar water heaters.

References

Tudor Jones, D. (2004). Solar water heating. SA plumbersâ&#x20AC;&#x2122; handbook (2004th ed., pp. 106). Edenvale: Pipe Trades Media Group.

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advertorial

Energy management for the future

Contact details For further information, visit http://www.dimensiondata. com/rgn/za/Solutions/ AdvancedInfrastructure or contact Dimension Data Advanced Infrastructure on 011-575-0000 or via e-mail at ai.information@dimensiondata.com

Energy Management is a term that has a number of definitions and a vast application.

Dimension Data is primarily concerned with how energy management relates to saving energy in businesses. When it comes to energy saving, energy management is the process of monitoring, controlling and conserving energy in a building or organisation.

Energy management is the sum of measures planned and carried out to achieve the objective of using the minimum possible energy while workplace comfort levels and production rates are maintained.

Before considering investing in an energy management solution, ask yourself the following questions: • Are you building a new office or development?

• Are you coping with current utility price increases?

• Do you have an energy efficiency policy or procedure in place?

• Do you plan to manage your energy consumption?

• Are you getting the most out of your energy utilisation?

Energy management is an ongoing cycle that follows a four-step process: etering energy consumption 1. M and collecting data from all

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2. Identifying opportunities to save energy, and estimating how much energy each opportunity could save. This would usually involve the analysis of meter data to find and quantify routine energy waste, and perhaps an investigation into the energy savings that could be achieved by taking various actions, such as replacing equipment (e.g. lighting) or by upgrading building insulation.

3. Taking action to target the opportunities to save energy (i.e. tackling the routine waste and replacing or upgrading inefficient equipment). Ideally, one would begin with the most impactful opportunities first.

4. Tracking progress by analysing meter data to see how well energy-saving efforts have worked, and then revisiting the second step to continue the process.

Energy management becomes relevant The current generation capacity crisis and associated rise in the price of power will continue to be the main drivers of growth in the South African building management systems market.

South African electricity is fast becoming an expensive commodity, accounting for a far

© Copyright Dimension Data 2011

20518_DPS_A5_R2.indd 1

16/01/2012 16:02

greater portion of a company’s operating costs than it did two or three years ago.

• Occupancy-based environmental controls;

Over the past two years and the current year, Eskom has implemented a 27 percent price hike for electricity usage, with a further 12 percent increase scheduled in the fourth and fifth years. Business cases for energyefficient projects, deemed too expensive and unnecessary a few years ago, are now being approved.

• Night setback, night ventilation purge;

This is spurring the demand for the installation of energy management systems to monitor, control and optimise building functions and equipment, thereby minimising energy and operational costs.

• Outside air reduction;

However, while systems for controlling various building equipment have been in use as long as commercial buildings have existed, the concept of an integrated energy management system to control and optimise building functions is relatively new in South Africa. A large majority of building owners and tenants are unable to fully understand the benefits of these systems and are often discouraged by the capital outlay involved. This low level of awareness is a significant challenge for the South African energy management systems market.

As a fully-fledged and active member of the Green Buildings Council of South Africa, Dimension Data has access to the latest trends and leading technologies available, ensuring we deliver unsurpassed energy management systems for each individual client’s needs.

Currently, only the largest and most complex buildings consider the installation of energy management systems.

The concept of a building management system is largely misunderstood or misinterpreted to imply a large capital outlay, with no realistic return on investment (ROI).

Dimension Data’s Building Energy Management Solution enables significant energy efficiency through a combination of: • Scheduled heating, ventilation, cooling and lighting control;

20518_DPS_A5_R2.indd 2

• Customisable energy reports;

• Optimal start/stop; • Chiller/boiler plant optimisation; • Heating/cooling equipment lockout; • Supply air temperature reset; • Variable Air Volume pressure and flow control; • Economiser control; • Electrical demand limiting; and • Domestic hot water control

Why Dimension Data?

Dimension Data offers a comprehensive carbon footprint evaluation as a service. This includes a full complement of consulting, professional and management services geared to help you accelerate your business ambitions around energy management. We also support clients throughout the entire lifecycle of buildings – providing training, technical help desk, regular inspection and function testing or call-out maintenance, remote monitoring and spare parts.

Dimension Data offers a scalable and user-friendly energy management system, with measurable ROI and energy savings. This is not only important for your own company, but also critical in fostering client loyalty and awareness.

Despite a low awareness from end-users, the demand for building management systems in response to the energy crisis is expected to accelerate the maturity of the industry in South Africa. Dimension Data offers best-of-brand solutions to suit client demands, with the ultimate goal of educating and offering customised solutions to improve comfort and productivity while eliminating energy wastage.

Key business benefits As evidenced by various energy management projects already implemented by Dimension Data, numerous benefits have emerged: • Energy cost savings: generally between 25 and 30 percent of the original energy expenses • Reduction in Green House Gas emissions: lower energy consumption helps reduce emissions • Financing: measured energy reductions help obtain grants for energy efficiency projects • Improved product and service costing: sub-metering allows the division of the energy bill between the different processes of an industry, and can be calculated as a production cost • Improved budgeting: Techniques can help forecast energy expenses in the case of changes in the business • Waste avoidance: helps diagnose energy waste in any process Energy management is truly an investment and not merely an expense. An organisation that practises energy management effectively stands to benefit not only from reduced costs based on reduced energy consumption, but also an improved public image and a more efficient workplace.

16/01/2012 16:02

greater portion of a company’s operating costs than it did two or three years ago.

• Occupancy-based environmental controls;

Over the past two years and the current year, Eskom has implemented a 27 percent price hike for electricity usage, with a further 12 percent increase scheduled in the fourth and fifth years. Business cases for energyefficient projects, deemed too expensive and unnecessary a few years ago, are now being approved.

• Night setback, night ventilation purge;

This is spurring the demand for the installation of energy management systems to monitor, control and optimise building functions and equipment, thereby minimising energy and operational costs.

• Outside air reduction;

However, while systems for controlling various building equipment have been in use as long as commercial buildings have existed, the concept of an integrated energy management system to control and optimise building functions is relatively new in South Africa. A large majority of building owners and tenants are unable to fully understand the benefits of these systems and are often discouraged by the capital outlay involved. This low level of awareness is a significant challenge for the South African energy management systems market.

As a fully-fledged and active member of the Green Buildings Council of South Africa, Dimension Data has access to the latest trends and leading technologies available, ensuring we deliver unsurpassed energy management systems for each individual client’s needs.

Currently, only the largest and most complex buildings consider the installation of energy management systems.

The concept of a building management system is largely misunderstood or misinterpreted to imply a large capital outlay, with no realistic return on investment (ROI).

Dimension Data’s Building Energy Management Solution enables significant energy efficiency through a combination of: • Scheduled heating, ventilation, cooling and lighting control;

20518_DPS_A5_R2.indd 2

• Customisable energy reports;

• Optimal start/stop; • Chiller/boiler plant optimisation; • Heating/cooling equipment lockout; • Supply air temperature reset; • Variable Air Volume pressure and flow control; • Economiser control; • Electrical demand limiting; and • Domestic hot water control

Why Dimension Data?

Dimension Data offers a comprehensive carbon footprint evaluation as a service. This includes a full complement of consulting, professional and management services geared to help you accelerate your business ambitions around energy management. We also support clients throughout the entire lifecycle of buildings – providing training, technical help desk, regular inspection and function testing or call-out maintenance, remote monitoring and spare parts.

Dimension Data offers a scalable and user-friendly energy management system, with measurable ROI and energy savings. This is not only important for your own company, but also critical in fostering client loyalty and awareness.

Despite a low awareness from end-users, the demand for building management systems in response to the energy crisis is expected to accelerate the maturity of the industry in South Africa. Dimension Data offers best-of-brand solutions to suit client demands, with the ultimate goal of educating and offering customised solutions to improve comfort and productivity while eliminating energy wastage.

Key business benefits As evidenced by various energy management projects already implemented by Dimension Data, numerous benefits have emerged: • Energy cost savings: generally between 25 and 30 percent of the original energy expenses • Reduction in Green House Gas emissions: lower energy consumption helps reduce emissions • Financing: measured energy reductions help obtain grants for energy efficiency projects • Improved product and service costing: sub-metering allows the division of the energy bill between the different processes of an industry, and can be calculated as a production cost • Improved budgeting: Techniques can help forecast energy expenses in the case of changes in the business • Waste avoidance: helps diagnose energy waste in any process Energy management is truly an investment and not merely an expense. An organisation that practises energy management effectively stands to benefit not only from reduced costs based on reduced energy consumption, but also an improved public image and a more efficient workplace.

16/01/2012 16:02

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chapter 11: Designing for South African Climate and Weather

Designing for South African Climate and Weather Dr Dirk Conradie Senior Researcher Built Environment CSIR

Introduction

To design energy efficient buildings using the correct combination of passive design strategies such as insulation, thermal mass and natural ventilation it is necessary to understand the particular climate very well. To perform a quantified building performance analysis by means of simulation software a detailed set of quantified climatic data is required.

The climate of an area is the averaging effect of weather conditions that have prevailed there over a long period of time such as 30 years. Due to the fact that earlier researchers did not have computers and electronic databases to research the gradual changes in climate Wladimir Köppen and Rudolf Geiger inter alia regarded climate as constant and used all of the sparse climate information available to compile a single climatic map1 (Rubel et al., 2010). Today we know that the climate is constantly changing over time due to a complex interaction of factors.

Climatic classification is an attempt to formalize the process of recognizing climatic similarity (Kruger, 2004). Some of the benefits of climatic classification are: • To indentify areas of influence of various climatic factors • To stimulate research to identify the controlling processes of climate • To inform an appropriate scientific response to building design

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Climatic classification

The climate regions of South Africa

Figure 11.1: Northern Arid bushveld 2. Central Bushveld 3. Lowveld Bushveld 4. South-Eastern Thornveld 5. Lowveld Mountain Bushveld 6. Eastern Coastal Bushveld 7. KwaZulu-Natal Central Bushveld 8. Kalahari Bushveld 9. Kalahari Hardveld Bushveld 10. Dry Highveld Grassland 11. Moist Highveld Grassland 12. Eastern Grassland 13. South-Eastern Cost Grassland 14. Eastern Mountain grassland 15. Alpine Heathland 16. Great and Upper Karoo 17. Eastern Karoo 18. Little karoo 19. Western Karoo 20. West Coast 21. north-Western Desert 22. Southern Cape Forest 23. South Grassland 15. Alpine Healthland 16. Great and Upper Karoo 17. Eastern karoo 18. little karoo 19. Western Karoo 20. West Coast 21. North-Western desert 22. Southern Cape forest 23. South Western Cape 24. Southern Cape

Low and Rebelo subdivided the seven vegetation biomes in South Africa into 68 vegetation types which consist of different concentrations of vegetation species. These types are mainly determined by climate, but sheltering, soil type, occurrence of veld fires, browsers such as goats and wild life, elevation and inclination and other minor factors also play a role. The boundaries for climatic regions were determined by making use of these vegetation types. Combinations of smaller vegetation type areas into larger regions that are easier to map and described from a climatic point of view, were made (Kruger, 2004).

Figure 11.1 illustrates these climatic regions. Nine Savanna-type climatic regions have been identified, six Grassland-type regions, five Karoo-type regions, two Fynbos-type regions, one Forest-type region and one Desert-type region.

SANS 204-2

The SANS 204-2 (2008) standard recognizes six main climatic regions in South Africa (Figure 11.2). It is an attempt to introduce a quantified view of climate into the National Building Standards. If this classification is compared with more detailed research work it is clear that much refinement would be required to support designers within the built environment. The chapter about fenestration in said document provides a detailed description of the calculation of conductance and solar heat gain for glazing elements supported by extensive look-up tables and diagrams.

For each of the six climatic zones tables are provided that gives the solar exposure factors and coefficients (SHGC) for various overhang/ height (P/H) factors for eight main orientation sectors. The standard is useful for initial desktop calculations. It is clear from SANS 204-2 (2008) what the beneficial impact of fenestration design in combination with appropriate sun protection could be. This should be quantified with more detailed calculations preferably with simulation software once the designer has determined the sun protection devices that will be used.

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Figure 11.2: Climatic zone map (SANS 204-2, 2008)

Table 11.1 below is a composite table that combines the description of SANS 204 climatic regions with the latest CSIR Kรถppen map and also some illustrative temperature characteristics of some cities that were obtained from Meteonorm2. It is interesting to note that the suggested Kรถppen classifications of the Table 11.1: Description of climatic zones (Colours correspond to those on the relevant climatic map)

Kรถppen CSIR, 2011

3

SANS 204-2 climatic zones Zone

1

Description

Major centre

Classification

Johannesburg

Cwb

Bloemfontein

BSk

Monthly and annual temperature ranges Climatic characteristics (Red = max, orange = normal highest, cyan = normal minimum, blue = minimum)

4

Cold interior

Cwa Pretoria 2

Cwb Bsh

Temperate interior Polokwane/ Pietersburg

BSk BSh

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3

4

Makhado/ Louis Trichardt

Cwa

Mbombela/ Nelspruit

Cwa

Cape Town

Csb

Hot interior

Temperate coastal

BSh Port Elizabeth Cfa

5

Sub-tropical coastal

East London

Cfa

Durban

Cfa

Richards Bay

Upington 6

Aw Cfa

BWh

Arid interior BSk Kimberley BSh

Meteonorm is a comprehensive climatological database for solar energy and climatological calculations applications. The Southern African data is base on 45 weather stations, that is enough to base fairly accurate building performance calculations on.

3 If more than one Kรถppen classification is shown it indicates that the particular City or Town has more than one climate type. For example due to the unique topography of Pretoria three distinct climatic zone scan be distinguished.

4 The illustrative temperature graphs were produced by using Meteonorm (.epw format) data in the Solar Advisor Model (SAM) provided by the National Renewable Energy Laboratory (NREL).

2

Meteonorm files differ slightly from the CSIR classification. The reason is that the CSIR Kรถppen map is based on a very high resolution 1 km x 1 km grid using 20 years worth of monthly temperature and precipitation data ranging from 1985 to 2005. Although the Kรถppen map is only based on

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precipitation and temperature it is a convenient way to check the validity of weather files used in more detailed building performance simulations. The reason for this is that if a particular weather file’s Köppen classification differs then it very likely used different data for precipitation and temperature.

The first three columns of Table 11.2 illustrate the SANS 204-2 climatic classification. The colours are as used in the SANS-204 norm. Columns four to six contains additional information. Column four contains the CSIR Köppen- Geiger classification that was derived from 20 years of monthly precipitation and temperature data on a 1 km x 1 km grid. The colours used here is identical to those used in the CSIR Köppen map. The formulae as described in detail by Kottek (2006) were used to calculate the classifications. It is clear that the SANS-204 classification is very coarse and an over simplification of the real situation. In the right hand columns some temperature graphs are shown that give an indication of the monthly and annual maximum, minimum and average temperature profiles.

Weather files

To calculate or simulate the expected building performance by means of desktop, spreadsheet or advanced software such as EnergyPlus or Ecotect reliable weather files are required. Weather files are normally created for different purposes as discussed below. Weather files typically contain seven main climatic aspects with an hourly interval. These aspects are dry bulb temperature, humidity, direct solar radiation, indirect solar radiation, wind strength/ direction, amount of cloud and precipitation.

Typical Meteorological Year (TMY)

A TMY is a set of hourly values of solar radiation and meteorological elements for a one year period. It consists of typical months selected from actual observed weather files from different years to form a complete year. The TMY weather files are intended for simulations of energy conversion and building systems. Due to the selection criteria, TMYs are not appropriate for simulations of wind energy conversion systems. (NREL, 1995) A TMY weather file provides a standard for hourly data for solar radiation and other meteorological elements that permit performance comparisons of system types and configurations for one or more locations. A TMY is not necessarily a good indicator of conditions over the next year, or even the next 5 years. It represents typical conditions over a long period of time, such as 30 years. This fact means that they are not suitable for designing systems and their components to meet worst-case conditions occurring at a location. (NREL, 1995) Both the original TMY and improved TMY2 data sets were created using similar procedures that were developed by Sandia National Laboratories. The Sandia method is an empirical approach that selects individual months from different years from the period of record. For example, in the case of the NSRDB that contains 30 years of data, all 30 Months of January are examined and the one judged most typical is selected to be included in the TMY. The other months of the year are treated likewise. The 12 selected typical months are then concatenated to form a complete typical year. (NREL, 1995) The 12 selected typical months for each station were chosen from statistics determined by using the five elements global horizontal radiation, direct normal radiation, dry bulb temperature, dew point temperature, and wind speed. These elements are considered the most important for simulation of solar energy conversion systems and building systems. For other elements in the TMY2 format the selected months may or may not be typical. Cloud cover, which correlates well with solar radiation, is probably reasonably typical. Other elements, such as snow depth, are not related to the elements used for selection; consequently, their values may not be typical. Even though wind speed was used in the selection of the typical months, its relatively low weighting with respect to the other weighted elements prevents it from being sufficiently typical for simulation of wind energy conversion systems and hence architectural designs where wind direction and speed is critical. (NREL, 1995) 186

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chapter 11: Designing for South African Climate and Weather

International Weather for Energy Calculations (IWEC)

The IWEC weather files are the result of ASHRAE Research Project 1015 by Numerical Logics and Bodycote Materials Testing Canada for ASHRAE Technical Committee 4.2 Weather Information. The IWEC weather files are described as “typical” weather files suitable for use with building energy simulation programs. IWEC weather data for more than 2100 locations are now available in EnergyPlus weather format This include 1042 locations in the USA, 71 locations in Canada, and more than 1000 locations in 100 other countries throughout the world. The weather data are arranged by World Meteorological Organization region and Country.

The files are derived from up to 18 years of DATSAV3 hourly weather data originally archived at the U.S. National Climatic Data Center. The weather data is supplemented by solar radiation estimated on an hourly basis from earth-sun geometry and hourly weather elements, particularly cloud amount information. An IWEC CD-ROM is available from ASHRAE. (ASHRAE, 2001) The Department of Energy has licensed the IWEC data from ASHRAE. The license with ASHRAE allows the U.S.A. Department of Energy to: • Distribute versions of the individual IWEC files in converted format suitable for EnergyPlus (EPW).

• Make the EnergyPlus versions of the IWEC files available to users at no cost via the EnergyPlus web site.

There are unfortunately only two IWEC weather files available for South Africa, i.e. Cape Town 688160 and Johannesburg 683680 obtainable from the EnergyPlus website.

Köppen-Geiger classification

While there are many different approaches to climatic classification empirical classifications such as the Köppen-Geiger classification is the most widely used. The first quantitative classification of world climates was presented by the German scientist Wladimir Köppen (1846 – 1940) in 1900. It has been available as a world map updated in 1954 and 1961 by Rudolf Geiger. Köppen was a trained plant physiologist and realised that plants are indicators for many climatic elements. His effective classification was constructed on the basis of five main vegetation groups determined by the French botanist De Candolle that referred to the climate zones of the ancient Greeks (Kottek, 2006). The five vegetation groups of Köppen distinguish between plants of the equatorial zone (A), the arid zone (B), the warm temperate zone (C), the snow zone (D) and the polar zone (E). A second letter in the classification considers the precipitation and a third letter the air temperature.

The CSIR created a new Köppen-Geiger map to quantify the current climatic conditions accurately as illustrated in Figure 11.3. This classification uses a concatenation of a maximum of three alphabetic characters that describe the main climatic category, amount of precipitation and temperature characteristics. (Table 11.2)

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PROFILE

Bethesda Omheining t/a Fence It Manufacturer We are a black owned enterprise established in 2003, aimed at supplying excellent products and service to the corporate, Government and the public with the security solution, we found our slogan that says â&#x20AC;&#x2DC;if you love it fence itâ&#x20AC;&#x2122;, the directors of the organisation decided to embark on business improvement which amongst others was to establish a manufacturing plant which is situated in the industrial hub of Middelburg Mpumalanga. We have also established young branches in Witbank, Polokwane, Manganeng in Sekhukhune and Mbombela which we hope to grow them to the sizable branches to handle the demands they will be faced with. Our company have professional staff that take every client serious and as important as our business since we value them as part of our business.

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chapter 11: Designing for South African Climate and Weather

Table 11.2: Köppen-Geiger categories (Kottek, 2006)

Main climates

Precipitation

Symbol

Description

Symbol

Description

Temperature Symbol

Description

A

equatorial

W

desert

h

hot arid

B

arid

S

steppe

k

cold arid

C

warm temperate

f

fully humid

a

hot summer

D

snow

s

summer dry

b

warm summer

E

polar

w

winter dry

c

cool summer

m

monsoonal

d

extremely continental

F

polar frost

T

polar tundra

Climate change

All indications are that we can expect a significant amount of climate change in South Africa. This will have a profound impact on the built environment and how buildings should be designed in the future.

Table 11.3: Current percentage of various Köppen categories in South Africa (Author)

Description

Köppen-Geiger Classification

Equatorial climates (0.2% of area)

Aw

Arid climates (70.89% of area)

Bsh

Area in km²

Percentage (%)

Cwc

2296.00 192269.00 275927.00 188784.00 164629.00 42918.00 93405.00 84.00 5120.00 18395.00 31162.00 140405.00 3564.00

0.20 16.59 23.81 16.29 14.20 3.70 8.06 0.01 0.44 1.59 2.69 12.11 0.31

Total

1158958

100.00

Bsk Bwh Bwk Warm temperate climates (28.91% of area)

Cfa Cfb Cfc Csa Csb Cwa Cwb

At the moment many research organizations are working on virtual advanced climate models known as General Circulation Models (GCM) in an attempt to quantify the likely effect. Table 11.3 illustrates the current percentage distribution of Köppen categories in South Africa. This is slowly changing.

In 1956 Norman Phillips developed the first successful climate model which could realistically depict monthly and seasonal patterns in the troposphere. Following Phillips’s work, several groups began to create their own GCMs. The first GCM that combined both oceanic and atmospheric processes was developed in the late 1960s at the North American Oceanic and Atmospheric (NOAA) Geophysical Fluid Dynamics Laboratory. By the early 1980s, the United States National Center for Atmospheric the green building HANDBOOK

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Research developed the Community Atmosphere Model. This model has been continuously refined into the 2000s. In a quest for more realistic forecasts efforts began in 1996 to factor in the effect of different soil and vegetation types. Advanced coupled ocean-atmosphere climate models such as the Hadley Centre for Climate Prediction and Researchâ&#x20AC;&#x2122;s HadCM3 are currently being used in climate change studies. (Wikipedia, 2011).

A good example of one such climate study is a study by Rubel (2010). In this study two global datasets of climate observations were selected to calculate future world maps of KĂśppen-Geiger climate classes. The first dataset was provided by the Climatic Research Unit (CRU) of the University of East Anglia. From this data only temperature was used. The temperature fields have been analyzed from time series observations which were checked for inconsistencies in the station records by means of an automated method. (Rubel et al., 2010) The second dataset was provided by the Global Precipitation Climatology Centre (GPCC) located at the German Weather Service. All observations in this station data base are subject to a multistage quality control to minimize the risk of generating temporal inconsistencies in the gridded data due to varying station densities.

Global temperature and precipitation projections for the period 2003-2100 were taken from the Tyndall Centre for Climate Change Research dataset. It comprised a total of 20 GCM runs that combines four possible future worlds of emission scenarios with five state-of-the-art climate models.

The emission scenarios were developed in the mid 1990s and are based on four different storylines.

Each storyline represents a different view of how the future world might look. Scenario A1 is a world with quick economic growth and with a quick launch of new and efficient technologies. A2 is a very heterogeneous world with a focus on family values and local traditions. B1 is a world without materialism and the launch of clean technologies. B2 is a world with a focus on local solutions for economic and ecological sustainability. (Rubel, 2010) The main variables in each model include population growth, economic development, energy use, efficiency of energy use and mix of energy technologies Rubel (2010).

Five general circulation models were used to simulate climatic changes, i.e. the Hadley Centre Coupled Model Version 3 (hadCM3), the National Center for Atmospheric Research-Parallel Climate Model (NCAR-PCM), the second Generation Coupled Global Climate Model (CGCM2), the Industrial Research Organization climate Model Version 2 (CSIRO2) and the European Centre Model Hamburg Version 4 (ECHam4).

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Figure 11.3 : CSIR Köppen-Geiger map based on 1985 to 2005 South African Weather Services data on a fine 1 km x 1 km grid (Author)

Figure 11.4: Predicted climate change for a A1FI scenario by the year 2100 (Heterogeneous world that is fossil fuel intensive) after Rubel (2010)

Figure 11.5: Predicted climate change for a B1 scenario by the year 2100 (World without materialism and clean technologies) after Rubel (2010)

The current climatic conditions in South Africa are illustrated in Figure 11.3. This accurate Köppen map was recently created by the CSIR from 20 years of temperature and precipitation data (1985 – 2005) based on a 1 km x 1 km grid. The algorithms as described by Kottek (2006) were used to compile the map. Table 11.1 relates the SANS-204 climatic classification to the CSIR Köppen classification. On the right of the table graphs obtained by post processing Meteonorm climatic data illustrate the temperature characteristics of some towns and cities.

Figure 11.4 and 11.5 illustrate the predicted climate change for an A1FI (fossil fuel intensive) and a B1 scenario by the year 2100 using the methods described above over the next century. It is clear that even with a change to clean technologies the country will become much dryer and hotter than the green building HANDBOOK

191

PROFILE

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chapter 11: Designing for South African Climate and Weather

present especially with regards to the current BWh (arid, desert, hot arid) and other arid regions. In all maps the same key applies as illustrated in Figure 11.3 or Table 11.1.

Conclusions

From the above it is clear that South Africa is a water stressed country and will become more so in future. Currently 0.2% of the country’s area is equatorial, 70.89% arid and 28.91% has a warm temperate climate. The climate change section suggests that water will become much scarcer and therefore designers will have to seriously consider rainwater harvesting and the use of permeable surfaces to reduce runoff so that the underground water sources can be replenished and also to avoid the destructive effect of large amounts of runoff during thunderstorms.

In previous chapters it was indicated that in general South Africa and cities such as Pretoria has high quality sunshine and solar radiation as well as a good climate. Many exciting opportunities exist to use the sun in the design of energy efficient buildings using the leitmotiv of the past in a modern context and supported by modern simulation software.

A photographic excursion indicated that architects are aware of sun protection measures, but are in many cases did not pay enough attention to the design not using it correctly. One of the elementary design mistakes, informed more by fashion than by reason, is architects’ infatuation with over-glazing.

This could lead to both overheating in summer and undercooling in winter or unwarranted airconditioning.

From other studies and publications it is clear that depending on the climatic region designers can go much further in using thermal mass, insulation, ventilation and solar penetration better.

Holm (1996) provides a detailed discussion of the possible measures that should be taken when designing for the different climatic zones in South Africa. There are a number of common misperceptions that some designers believe will be the solution to all problems (Holm, 1996). Examples of these misconceptions are: • Insulation is the answer to all thermal problems.

• Lots of mass is the answer.

• Ventilation is the answer.

• The larger north windows are, the better.

Advanced software products make it now far easier to qualify and quantify the effect of a particular building design before construction. Simulation makes it feasible to test various design scenarios or research hypotheses. A good understanding of the basic principles will lead to far better “climate aware” and environmentally conscious energy efficient architecture.

One of the accessible methods is to use a bioclimatic chart. “Bioclimatic” design is used to define potential building design strategies that utilize natural energy resources and minimize conventional energy use. (Visitsak, 2004). This approach to building design for maintaining indoor comfort conditions was first developed by Olgyay (1963). In 1969 the bioclimatic chart was significantly improved by Givoni (Givoni, 1969). To address the problems of the original Olgyay chart, Givoni developed a chart for “envelop-dominated buildings” based on indoor conditions. In 1979, Milne and Givoni combined the different design strategies of the previous study of Givoni (1969) on the same chart. The GivoniMilne bioclimatic chart (Milne and Givoni, 1979) is currently used by many architects in the U.S.A. Software such as Ecotect has a psychometric chart with Givoni-Milne overlays.

Table 11.4 below suggests some passive design strategies using the principles of the Givoni-Milne approach that could be used to improve the comfort of buildings in the context of various different climatic regions in South Africa. the green building HANDBOOK

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chapter 11: Designing for South African Climate and Weather

Percentage (%)

Passive design Strategy

Table 11.4: Some suggested passive design strategies for the different climatic regions of South Africa (Author)

Climatic Characteristics Area in km²

Description

Natural Ventilation

Indirect Evaporative Cooling

Thermal Mass

Exposed Mass and Night purge Ventilation

Direct Evaporative Cooling

Passive Solar Heating

KöppenGeiger Classification

0.2



2296



Aw



Equatorial climates (0.2%)



16.59 

192269

23.81



Bsh 275927

16.29



 





Bsk 188784

14.2













Arid climates (70.89%)

Bwh

164629

3.7





Bwk

42918

8.06







Cfa

93405

0.01





Cfb

84

0.44







Cfc

5120

1.59









Csa

18395

2.69







Csb

31162

12.11



Warm temperate climates (28.91%)

Cwa

140405

0.31

Cwb

3564



Cwc

100

1158958

Total

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References

ASHRAE. 2001. International Weather for Energy Calculations (IWEC Weather Files) Users Manual and CD-ROM, Atlanta: ASHRAE Givoni, B. 1969. Man, Climate and Architecture. Elsevier Publishing Co. Ltd., New York, NY. Holm, D. 1996. Manual for Energy Conscious Design. Department of Minerals and Energy Directorate Energy for Development.

Kottek, M., Grieser, J., Beck, C., Rudolf, B. Rubel, F. 2006. World Map of the Köppen-Geiger climate classification updated. Meteorologische Zeitschrift, Vol. 15, No. 3, 259-263 (June 2006).

Kruger, A.C. 2004. Climate Regions – Climate of South Africa. South African Weather Service.

Marion, W., Urban, K. 1995. User’s manual for TMY2s Typical Metheorological Years. National Renewable Energy Laboratory (NREL), Colorado.

Milne, M., and Givoni, B. 1979. Architectural Design Based on Climate, in D. Watson (Ed.), Energy Conservation Through Building Design, McGraw-Hill, Inc. New York, NY: 96-113.

Olgyay, V. 1963. Design With Climate: Bioclimatic Approach to Architectural Regionalism. Princeton University Press, Princeton, NJ: 14-32.

Rubel, F., Kottek, M. 2010. Observed and projected climate shifts 1901 – 2100 depicted by world maps of the Köppen-Geiger climate classification. In Meteorologische Zeitschrift, Vol 19, No. 2, 135-141.

SANS 204. 2008. South African National Standard. Energy efficiency in buildings, Part 1: General requirements. SABS Standards Division.

SANS 204. 2008. South African National Standard. Energy efficiency in buildings, Part 2: The application of the energy efficiency requirements for buildings with natural environmental control. SABS Standards Division.

Wikipedia. 2011. Global Climate Model. http://en.wikipedia.org/wiki/Global_climate_model. Accessed 20 October 2011.

U.S. Department of Energy. 2011. EnergyPlus Energy Simulation Software. http://apps1.eere.energy.gov/buildings/energyplus/weatherdata_about.cfm .

Accessed 3 October 2011.

Visitsak, S. Haberl, J.S. 2004. An Analysis of Design Strategies for Climate-Controlled Residences in Selected Climates. In proceedings of SimBuild 2004, IBPSAUSA National Conference, Boulder, CO, August 4-6, 2004.

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PROFILE

Vrede Textiles VREDE TEXTILES, a manufacturer of fabrics for roller blinds and vertical blinds, was established in 1975 and is situated in the Western Cape of South Africa.

Vrede Textiles, prides itself in being a success story wherein Vivian and Susan Jacobs, former employees of the company, diligently and with persistent labour, became owners and shareholders of the company. Being a member of the Proudly South African® campaign, a member organization of the Green Building Council of South Africa and a verified Level 1 BEE company (102.33%) makes this company a fine example of what many South African entities can become.

Vivian believes that their most valuable asset is the labour force of 60 loyal employees representing hundreds of years in experience, all from the Atlantis area and surrounds, and who, at every level, contributes to the success of the business.

The company’s mission is to produce modern, trend setting fabrics manufactured to a consistent high quality and distributed through reliable, easily accessible sales channels which deliver the best possible buying experience and actively encourage two-way communication and client feedback.

Our vision is to build a socially responsible company of which every employee is justifiably proud. A company which not only delivers the best possible returns to its shareholders but also makes a meaningful contribution to the upliftment of its local community by providing stable, reliable job opportunities that encourage and motivate every employee to develop to their full potential.

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Dulux is a proud level five B-BBEE contributor.

chapter 12: Thermal mass vs. insulation building envelope design in six climatic regions of South Africa

Thermal mass vs. insulation building envelope design in six climatic regions of South Africa Tichaona Kumarai Researcher (Building Performance Analysis) Built Environment CSIR

Dr Dirk Conradie Senior Researcher Built Environment CSIR

Introduction

Experience shows that there are a number of building design traps that are very tempting for designers. A typical example of this is that insulation is the answer to all thermal problems. The addition of insulation without attention to thermal mass and air infiltration will not only cause additional expenditure but also worsen indoor conditions. Quite often a lot of thermal mass is seen as the answer. Lots of mass reduces the temperature swing towards the average temperature which may be either too high or too low for comfort. This implies that mass must be considered together with night cooling or solar heating (Holm, 1996).

Heating, ventilation and air-conditioning (HVAC), contribute an estimated 5 400 MW to electricity demand in peak periods in South Africa. This is approximately 15% of South Africa’s current peak demand consumption. On an annual basis, HVAC accounts for some 4 000 gigawatt hours of electricity consumption in South Africa (ESKOM, 2010).

Buildings’ air conditioning loads arise from energy that flows into a building through its envelope, solar gains through windows, infiltration, and ventilation bringing in outside air that needs to be cooled and or dried, plus heat and moisture that are generated within the building (Duffie et al., 1980).

Better design of new buildings could result in a 50-75% reduction in their energy consumption (Clarke, 2001). Appropriate interventions in the existing building stock would reduce energy use significantly.

Added together, this could significantly reduce the nation’s energy bill and positively contribute to environmental impact and climate change mitigation. This would also help to alleviate the stressful indoor conditions experienced by many citizens. Indeed energy efficiency may be likened to an untapped, clean energy resource of vast potential (Clarke, 2001).

This chapter aims to evaluate the impact of thermal mass and high insulation (R- value) building envelope on energy consumption (space heating and space cooling) in six South African major cities using a building thermal simulation programme (EcotectTM V 5.6).

Thermal mass and insulation

Insulation and thermal mass are similar in that they both slow down the movement of heat between exterior and interior spaces, but they are also different with respect to other characteristics.

High density materials such as concrete, brick, tiles, earth and water require a significant amount of heat to increase their temperature. They also lose heat slowly and are referred to as having a high thermal mass. In contrast low density, lightweight materials such as insulators (high Rvalue materials) require little heat to increase their temperature but also lose heat rapidly. The latter are referred to as low thermal mass materials. A material suitable for thermal mass must have: • high heat capacity • high density • low reflectivity (i.e. a dark, or textured finish). the green building HANDBOOK

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It is clear that thermal mass is not the same as insulation, which, in building terms, describes a building’s ability to reduce the conduction (or flow) of heat between indoors and outdoors. The term thermal mass is used by Goulart (2004) to describe a building’s overall capacity to store and release heat. In general, it is contained in walls, partitions, ceilings and floors of the building, which are constructed of materials of high heat capacity.

3 Methodology The methodology adopted to investigate aforementioned included inter alia infiltration rate measurements, development of the Ecotect simulation model and simulation of houses with base case characteristics and energy efficient measures in six South African cities.

Building infiltration rate measurements

High infiltration rates means a leaky building meaning the beneficial effects of insulation are destroyed.

Tracer gas tests were used to measure the infiltration rate for a light steel frame (LSF) house which was built on the CSIR building performance laboratory test site. Carbon dioxide was injected into the house with windows and doors closed during the tracer gas tests. The dilution was monitored over time (See Figure 12.1) to determine how quickly the gas dissipates through the house’s leaky envelope.

A non-dispersive infra-red absorbance (NDIR) gas sensor was used to monitor indoor carbon dioxide concentration. The carbon dioxide sensor was placed at height of about 0.45 m above the finished floor level. This height was used to take account of infiltration underneath doors as well.

Figure 12.1:Tracer gas concentration decay for the whole 40 m2 LSF house at the CSIR building performance laboratory

Figure 12.2: logarithmic graph of CO2 concentration versus time

According to the ASHRAE (1997) fundamentals Handbook the carbon dioxide decays exponentially (assuming perfect mixing) and at any time t is given by the following expression: .......... (1) Where I is the air change rate per hour C is the concentration of carbon dioxide is time Co is the concentration of carbon dioxide at

= 0.

Taking logarithms both sides of Eq. (1), the equation becomes: , and differentiating with respect to time ( q ) the air exchange rate (in minutes) can be approximated by the gradient of the linear regression straight line of best fit as illustrated in Figure 12.2.

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From Figure 12.2 the gradient from the linear equation is 0.0095 Air Changes (AC) per minute. To calculate the numbers of air changes per hour this gradient was multiplied by 60 (since the time record was in minutes) and this gives 0.57 Air Changes per Hour (ACH).

Building modelling

The construction details for each of the two houses were modelled using Ecotect. Weather files for Pretoria, Bloemfontein, Cape Town, Durban, Musina and Kimberley South Africa were uploaded in the software model. These cities were chosen because they represent different climatic regions as shown on the Köppen Geiger map (Green building Handbook, Volume 4, 2011. Chapter 12). Two models (virtual scientific representation of the two construction methods used to run comparative predictive simulations) were prepared for the two houses detailed in Figures 12.3 and 12.4, using the plan measurements detailed in Figure 12.5. The two base case models used different structural construction technologies for their walls. The masonry house used clay bricks for heavy weight and consequently high thermal mass. The LSF house used light steel frames in combination with glass wool for a light weight or high R-value type model in accordance with SANS 517 (see detail of construction detail in Table 12.2). All parameters such as floor area, ceiling height, arrangement for zones and orientation for the two models were identical. Some new material composites were introduced in the materials database to represent typical building materials used in the construction of heavy weight and light weight buildings in South Africa. The thermal property values (U-values, thermal decrement, admittance, solar absorption and visible transmittance) for these composites materials were calculated. One of the shortcomings of Ecotect when creating new material composites is that it is not able to calculate thermal lag for user defined materials. To address this shortcoming Ecomat™ v1.0 software was acquired and used for this purpose. Ecomat calculates thermal lag according to the EN ISO 13786:2007 standard. The standard is termed “Thermal performance of building components - Dynamic thermal characteristics - Calculation method (ISO 13786:2007).” This method corresponds with CIBSE Admittance Method, which is the method used by Ecotect for its thermal calculations.

Figure 12.3: 3-Dimensional perspective view of the Thermal model, with individual colour for each zone developed in Ecotect V 5.6.

Figure 12.4: Visual 3-Dimensional thermal model showing Southern & Eastern facades developed in Ecotect V 5.6.

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RADIANT HEAT BARRIER

AFRICA THERMAL INSULATIONS

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chapter 12: Thermal mass vs. insulation building envelope design in six climatic regions of South Africa

Figure 12.5: Residential building plan used in thermal analysis.

Considerations in the model

Building material thermo physical properties Due to the large differences in the thermal conductivity of the steel used in combination with glass wool thermal insulation within the wall structure of the light steel house a limited amount of unavoidable thermal bridging occurs. In this study the BS EN ISO 6946:1997 Uvalue calculations procedure (Doran and Kosmina, 1999) was used to calculate the U-value of the light weight house internal and external walls taking the thermal bridging into account. Other building material thermal properties such as density, specific heat capacity and conductivity were obtained from the Ecotect materials library, South African Light Steel Association and from Clarke et al., 1990.

Zones A thermal zone is defined in Ecotect as a homogenous enclosed volume of air. In most cases this corresponds to a single room. It is assumed that the air within a zone is able to mix freely. Every room in the simulation model was defined as distinct thermal zone. This was done to simulate and quantify the thermal exchanges between the rooms. Table 12.1 shows the total area that includes surface areas, floor areas and volumes for all the thermal zones of both houses. These values were calculated with Ecotect. These values are important because the volume of air circulating within each of the thermal zones will have a large impact on the resultant indoor temperature. The total area (second column Table 12.1) represent the total surface areas through which heat transfer occurs. Row 12 of Table 12.1 shows that the total floor area for each of the houses is 119.545 m2 and the total volume of air that can be enclosed within all the Zones is 286.983 m3, excluding the roof.

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Table 12.1: Zone areas and zone volumes for the LSF and masonry houses as calculated in Ecotect.

Zone

Total area (m2)

Floor area (m2)

Volume (m3)

Dining / lounge

124.217

32.229

77.521

Passage

89.093

13.088

31.169

Bedroom 1

60.365

12.902

30.966

Bedroom 2

57.715

12.130

29.143

Bedroom 3

73.018

16.619

39.875

Bathroom en-suite

42.244

7.754

18.651

Bathroom

35.871

6.055

14.565

Toilet

29.908

4.466

10.743

Laundry

29.703

4.411

10.611

Kitchen

50.263

9.891

23.739

Sub total

592.397

119.545

286.983

Roof Zone

299.158

121.380

88.165

Total

891.555

240.925

375.148

Internal gains Internal heat gains occur due to occupancy, lighting and equipment. In order to assess and compare the passive thermal performance of the light weight and heavy weight houses, the value for internal gains was assigned as zero in each of the thermal zones for both houses. This was done in order to assess the pure comparative passive thermal performance of the envelope of the two houses without interference from other complicating factors.

Infiltration Infiltration rate is measured in ACH and specifies air leakage within the zone through cracks and gaps.

The quality of the workmanship during construction greatly influences this. This rate ranges from 0.25 ACH for air tight buildings to 2.0 for leaky ones in the Ecotect software. Carbon dioxide tracer gas tests carried out at the CSIR Building Performance Laboratory yielded 0.57 ACH (infiltration rate) for a light weight 40 m2 test house. In this analysis an infiltration value of 0.57 ACH for all the thermal zones of the light weight and heavy weight houses was assumed.

The infiltration value (0.57 ACH) was assumed to be the same for the two simulations mainly for strict comparative purposes. In practice infiltration rate is dependent on workmanship and building quality and would be different for each housing unit.

It is important to specify wind sensitivity, which means sensitivity of the zone to wind speed according to a specified sheltering level. This is an additional air change rate value, over and above the base infiltration rate. Ecotectâ&#x201E;˘ sets wind sensitivity to 0.1 ACH when the building is wind-sheltered and 1.5 ACH when building is exposed to wind. In this study a wind sensitivity of 0.1 ACH was assumed in all the thermal zones for both the light weight and heavy weight houses. It was assumed that surrounding buildings provide some sheltering as is the case on the CSIR test site.

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Comfort band The temperature comfort band for an air conditioned building used in this study is (20Ë&#x161;C - 24Ë&#x161;C) as recommended in SANS 204:201 (2011). For this study, this band was assumed for all the thermal zones.

The zones are artificially assumed to be air conditioned for the software to be able to calculate heating and cooling loads. The acceptable range of humidity levels in buildings is between 30% - 60% for an energy efficient building SANS 204:201 (2011). For this study a design relative humidity of 60% was assigned to all the thermal zones. The design average air velocity must not be higher than 0.8 m/s (ANSI/ ASHRAE. 2004). For this study a design air velocity of 0.7 m/s was assumed for all the thermal zones to avoid un comfortable draughty conditions.

Occupancy To compare the thermal performance of the two houses, operational schedules and occupancy were assumed to be identical. Both cases were assumed to be operating for 24 hours in order to assess the diurnal thermal performance. Zero occupancy was assumed in each case in order to simplify the analysis.

Detailed description of the high thermal mass and light weight (insulated) reference house Table 12.2: Detailed description of the high thermal mass (Case A) and light weight (insulated) (Case B) reference houses

Element

Low mass ( high insulation/ R- value house)

High thermal mass house

Roof

30 mm concrete tiles , 38 mm Air gap, 0.2 mm polyethylene (high density). Uvalue = 2.59 W/m2.K, Thermal lag = 0.82 hrs

30 mm concrete tiles, 38 mm Air gap, 0.2 mm polyethylene (high density). Uvalue = 2.59 W/m2.K, Thermal lag = 0.82 hrs

External walls

9 mm fibre cement sheet, 0.2 mm vapour membrane, 30 mm OSB board, 102 mm glass wool insulation in combination with 0.8 mm steel studs, 15 mm gypsum board.

Uvalue = 0.5402 W/m2.K, Thermal lag = 2.6 hrs

15 mm Cement plaster, 220 mm Brick normal fire Clay, 15 mm Cement plaster. Uvalue = 2.72 W/m2.K, Thermal lag = 6.05 hrs

Internal walls

9 mm fibre cement sheet, 0.2 mm vapour membrane, 30 mm OSB board, 102 mm glass wool insulation in combination with 0.8 mm steel studs, 15 mm gypsum board.

Uvalue = 0.5402 W/m2.K, Thermal lag = 2.6 hrs

15 mm Cement plaster, 110 mm Brick normal fire Clay, 15 mm Cement plaster. Uvalue = 3.54 W/m2.K, Thermal lag = 3.24 hrs

ceiling

6.4 mm gypsum board. Uvalue = 5.58 W/m2.K, Thermal lag = 0.06 hrs

6.4 mm gypsum board. Uvalue = 5.58 W/m2.K, Thermal lag = 0.06 hrs

Floor

75 mm Concrete 1-4 dry, 10mm cement screed. Uvalue = 3.51 W/m2.K, Thermal lag = 2.15 hrs

75 mm Concrete 1-4 dry, 10mm cement screed. Uvalue = 3.51 W/m2.K, Thermal lag = 2.15 hrs

1

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PROFILE

Italdoor Define your taste â&#x20AC;&#x201C; the complete door kit solution promises cutting-edge standards in terms of quality, design and door installation.

Italdoors is a company known for its variety in doors and its complete excellence and longstanding commitment to residential, corporate, educational and civic institutes with projects being completed all over Africa.

Italdoors have been operating in South Africa since 2006 and have completed projects with prestigious contractors such as Basil Read and Murray & Roberts. It provides a range of imported and complete pre-finished and assembled eco friendly green Italian door kits. Its range of doors is courtesy of world famous designers such as Ettore Sottsass, artists like Tonino Guerra and internationally renowned architects such as Gae Aulenti.

Italdoors offer an innovative solution to hospitals, hotels and the domestic market making them socially, economically and environmentally responsible. The doors help create a healthy and more productive environment for people to live and work in. Its doors are not harmful to the environment or to its inhabitants thereby minimizing harm to the natural world.

The complete door kit range consists of the Basic, Hotel, Gae Aulenti, Halley, Hospital, Linear, Miti, Rubicone, Sottsass associate and the Wellness door range.

Italdoors have a FSC Chain of Custody seal (recognized at world level). This seal is only applied to doors and windows if the ability to track backwardly the timbers used in manufacture of the products to be sealed can be guaranteed, through separation/identification of the raw materials at both warehouse and woodworking level.

Therefore, it must be proven that the products to be FSC sealed are made from materials originating from suppliers who adhere to FSC protocol, which requires forestry management according to strict environmental, social and economic standards.

It has the PEFC Chain of Custody seal (recognized at European level). Similarly to the FSC, this organisation promotes sustainable forestry management and uses similar methods. Italdoors are PEFC Chain of Custody certified and are certified for forestry management. At a European and British level, however, many sawmills used by Italdoors have already obtained this certification, such as the Swedish companies Skogsägarna and Moelven, and the Finnish companies Finnforest, Luvian, Stora Enso.

120 Design quarter, Cnr William Nicol & Leslie Ave, Fourways Tel : 087 940 0560 Fax : 086 716 3843 Email: vitto@italdoors.co.za www.italdoors.co.za

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Table 12.3: Detailed description of high thermal mass and light weight (high R-value) alternative building envelope materials for energy evaluation. (The colour codes matches the bar graphs colours in Figures 6 and 7 below)

Case

Roof

External wall

Internal wall

Ceiling

Floor

Same as in Table 12.2

Same as in Table 12.2 under low mass (high R-value house)

Same as in Table 12.2 under low mass (high R-value house)

140mm glass wool insulation, 6.4 mm gypsum board.

Uvalue = 0.26 W/ m2.K, Thermal lag = 0.44 hrs

Same as in Table 12.2

30 mm concrete tiles, 0.2 mm polyethylene (high density) and 40 mm isotherm insulation. Uvalue = 0.93 W/m2.K, Thermal lag = 0.96 hrs

Same as in Table 12.2 under low mass (high R-value house)

Same as in Table 12.2 under low mass (high R-value house)

140mm glass wool insulation, 6.4 mm gypsum board.

Uvalue = 0.26 W/ m2.K, Thermal lag = 0.44 hrs

Same as in Table 12.2

Same as in Table 12.2

15 mm plaster, 220 mm dense concrete and 15 mm plaster.

Uvalue = 3.05 W/ m2.K, Thermal lag = 6.3 hrs

Same as in Table 12.2 under high thermal mass house

140mm glass wool insulation, 6.4 mm gypsum board.

Uvalue = 0.26 W/ m2.K, Thermal lag = 0.44 hrs

Same as in Table 12.2

Same as in Table 12.2

15 mm cement plaster, 110 mm brick normal fire clay, 50 mm mineral wool insulation, 110 mm brick normal fire and 15 mm cement plaster.

Uvalue = 0.59 W/ m2.K, Thermal lag = 9.08 hrs

Same as in Table 12.2 under high thermal mass house

140mm glass wool insulation, 6.4 mm gypsum board.

Uvalue = 0.26 W/ m2.K, Thermal lag = 0.44 hrs

Same as in Table 12.2

C

D

E

F

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Table 12.4: Continuation of Table 12.3

Same as in Table 12.2

15 mm cement plaster, 50 mm mineral wool insulation, 220 mm brick normal fire clay, 50 mm mineral wool insulation and 15 mm cement plaster. Uvalue = 0.33 W/m2.K, Thermal lag = 10.16 hrs

Same as in Table 12.2 under high thermal mass house

140mm glass wool insulation, 6.4 mm gypsum board.

Uvalue = 0.26 W/ m2.K, Thermal lag = 0.44 hrs

Same as in Table 12.2

Same as in Table 12.2

15 mm plaster, 220 mm dense concrete and 15 mm plaster. Uvalue = 3.05 W/m2.K, Thermal lag = 6.3 hrs

Same as in Table 12.2 under high thermal mass house

Same as in Table 12.2

Same as in Table 12.2

Same as in Table 12.2

15 mm cement plaster, 110 mm brick normal fire clay, 50 mm mineral wool insulation, 110 mm brick normal fire and 15 mm cement plaster. Uvalue = 0.59 W/m2.K, Thermal lag = 9.08 hrs

Same as in Table 12.2 under high thermal mass house

Same as in Table 12.2

Same as in Table 12.2

G

H

I

Results

Table 12.5 and 12.6 below show the annual heating and cooling loads for the six cities representing the Koppen Geiger climatic classifications shown in column one of said Tables.

Table 12.5: Annual cooling demand in six cities

K2 Cwa BSk Csb Cfa BWh BSk

 CASE Pretoria Cooling load (KWh) Bloemfontein Cooling load (KWh) Cape Town Cooling load (KWh) Durban Cooling load (KWh) Musina Cooling load (KWh) Kimberly Cooling load (KWh)

A

B

C

D

E

F

G

H

I

6 046.91

4 439.42

525.13

478.87

798.92

471.09

590.87

5 813.95

5 186.31

4 995.50

3 771.85

280.88

250.87

593.55

341.90

411.86

4 797.00

4 335.69

1 117.51

991.46

69.85

61.30

80.73

36.61

61.77

1 035.62

900.22

9 391.59

6 442.18

1 360.80

1 293.25

1 970.85

1 293.18

1 493.28

9 145.24

8 164.67

41 147.68

31 139.10

10 643.75

10 484.29

15 259.71

11 892.62

12 187.56

40 645.81

37 538.19

15 642.28

10 332.86

1 728.77

1 637.92

3 038.71

2 018.94

2 243.11

15 334.23

13 933.13

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Figure 12.6: Annual space cooling demand in six cities Table 12.6: Annual heating demand in six cities

K Cwa BSk Csb Cfa BWh BSk

 CASE Pretoria heating load (KWh) Bloemfontein heating load (KWh) Cape Town heating load (KWh) Durban heating load (KWh) Musina heating load (KWh) Kimberly heating load (KWh)

A

B

C

D

E

F

G

H

I

21 600.29

20 307.96

11 196.06

11 177.17

14 804.75

13 327.23

13 146.98

21 427.15

19 649.06

47 299.20

43 551.14

23 848.02

23 831.99

31 361.26

27 962.45

27 381.19

46 980.13

43 211.90

35 596.66

33 405.28

20 007.02

20 020.35

25 679.62

23 284.22

22 787.06

35 375.53

32 516.32

6 832.69

6 408.08

3 336.42

3 318.52

4 774.33

4 145.06

4 126.92

6 761.17

6 087.11

2 328.40

2 102.31

921.17

906.54

1 774.83

1 379.41

1 379.73

2 293.03

1 887.30

25 118.54

22 559.33

10 823.55

10 812.93

15 328.35

13 260.13

12 937.77

24 943.25

22 614.46

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Figure 12.7: Annual space heating demand in six cities

Analysis of results

Figures 6 and 7 indicate that some cities require far more space heating and cooling than others. This correlates to the intensity of winter and summer months in these cities. Bloemfontein has the highest space heating energy requirements and Musina has the least space heating energy requirement.

Cape Town has the least space cooling energy requirement and Musina has the highest space cooling energy requirement.

In cases C, D, E, F and G the lengths of the bar graphs for both heating (Figure 12.7, Table 12.6) and cooling (Figure 12.6, Table 12.5) are shorter in all six cities when compared to lengths of bar graphs for cases A, B, H and I (See Tables 12.2 , 12.3 and 12.4). The difference between cases C, D, E, F and G and A, B, H and I is that C, D, E, F and G has 140 mm glass wool on the 6.4 mm gypsum ceiling board whereas cases A, B, H and I has only 6.4 mm gypsum board as ceiling. This result indicate the importance of ceiling insulation. This is a passive intervention that is effective for both heating in winter and cooling in summer in all the six South African climatic regions investigated.

In cases C and D, the lengths of bar graphs for both heating and cooling are similar for both cases (C and D) in the six cities. The difference between construction C and D is that D has 40 mm isotherm roof insulation. The fact that the heating and cooling loads remain similar even after adding roof insulation on top of ceiling insulation indicates that adding roof insulation on top of an insulated ceiling does not change the heating and cooling loads in all the six cities.

The bar graphs for cases C and D are the shortest for both space heating and space cooling in all the six cities when compared to lengths of bar graphs for cases A, E, F, G, H and I. Cases C and D are constructed from high Rvalue and low thermal mass building envelope materials when compared to cases A, E, F, G, H and I. Therefore high Rvalue and low thermal mass building envelope materials are much more energy efficient when compared to low Rvalue and high thermal mass building envelope materials in the six cities.

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Conclusions

When designing buildings in the six cities that represent a cross section of climatic conditions in South Africa, ceiling insulation (below the roof ) is beneficial.

Given the materials stated in detail above, highly insulated walls and ceilings results in lowest heating and cooling requirements in all six cities.

This Chapter analysed heating and cooling requirements only. However there are other factors as well that are not addressed in this Chapter such as indoor temperature variation and thermal comfort.

From simulations that are not shown in this Chapter, thermal mass has been shown to decrease temperature swings and light weight steel has high temperature variations.

As already discussed above, a highly insulated building saves space conditioning energy. For a high thermal mass building to match the insulating capacity of a highly insulated building, it requires quite a substantial structure. A combination of both insulation and thermal mass will be more beneficial (refer to cases F and G).

Simulation aimed at investigating different combinations of thermal mass and insulation was also undertaken. In this case 100 mm polystyrene insulative layer was put under the floor slab. A surprising result was that number of thermal discomfort hours (too hot hours) increased by a factor of 158% (Kumirai, et al. 2011, Willrath). From this it was concluded that the insulation under the floor increasingly isolates the room from the thermal mass of the ground.

References

ANSI/ASHRAE. 2004. Standard 55-2004. Thermal Environmental Conditions for Human Occupancy.

ASHRAE. 1997. Heating Ventilation & Air Conditioning fundamentals Handbook.

Clarke, J.A. 2001. Energy Simulation in Building Design. Butterworth-Heinemann Linacre House, Jordan Hill, Oxford OX2 8DP, 225 Wildwood Avenue, Woburn, MA 01801-2041. A division of Reed Educational and Professional Publishing Ltd. Clarke, J.A., Yaneske, P.P., Pinney, A.A. 1990. The Harmonisation of Thermal Properties of Building Materials. BRE Publication, BEPAC Research Report.

Doran S M and Kosmina L. 1999.Examples of U-value calculations using BS EN ISO 6946:1997. December 1999 Report No 78129.

Duffie J.A. & Beckman W.A. 1980. Solar Engineering of thermal processes. Second edition a wiley-interscience publication John Wiley & sons Inc. New York Chichester Brisbane Toronto Singapore.

ESKOM. 2010. Demand side management – air-conditioning facts. http://www.eskom.co.za/content/dsm_0002airconfactsrev2~1.pdf ..Accessed 4 November 2011.

Goulart S.V. G. 2004. Thermal Inertia and Natural Ventilation – Optimisation of thermal storage as a cooling technique for residential buildings in Southern Brazil.

A thesis submitted in partial fulfilment of the requirements of the Open University for the degree of Doctor of Philosophy Holm, D. 1996. Manual for Energy Conscious Design. Department of Minerals and Energy. http://www.ecoeficiente.es/ecomatHelp/index.htm?Features.html, accessed 25 November 2009.

Kumirai, T., and Conradie, D.C.U. 2011. A predictive comparative thermal performance analysis for light steel frame and masonry residential buildings: indoor temperatures, loads and thermal comfort. Unpublished report CSIR, Built Environment, Pretoria.

SANS 204:201. 2011. Edition 1. SOUTH AFRICAN NATIONAL STANDARD. Energy efficiency in buildings. Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001 Willrath H. Comparison of the Thermal Performance of Free Running and Conditioned Houses in the Brisbane Climate. Department of Architecture University of Queensland

(Footnotes)

1 Order of material layers is from outside to inside 2 K refers to Köppen-Geiger climatic map published in Green Building Handbook Volume 4, 2011, Chapter 12.

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PROFESSIONAL PROJECT PROFILE

Integrated environmentally sustainable design The current economic situation has meant that large project owners are starting to question the possibility of prioritising their overall spend in order to ensure they occupy a ‘sustainable’ building.

By managing a building’s energy and water usage, amongst others, it is possible to ensure buildings make a positive contribution to the environment in which they operate.

Project 1: Aurecon Centre, Century City, Cape Town South Africa’s first ever 5 Star Green Star SA building

Aurecon’s office building in Century City, Cape Town, which was completed in August 2011, is the first building in South Africa to be awarded a 5 Star Green Star SA – Office Design v1 rating by the Green Building Council of South Africa (GBCSA).

Developed by the Rabie Property Group at a cost of around R130 million, the 7000 square metre office block is also the first building in Cape Town and only the fifth country-wide to achieve Green Star accreditation from the GBCSA. Aurecon was responsible for the design of all the engineering services on the project.

Albert Geldenhuys, Aurecon’s General Manager: South Africa, said that: “Increasingly, it has become important to demonstrate that our own buildings and facilities have been built in a sustainable manner. The group is committed to ensuring that we design and execute sustainable and environmentally responsible infrastructure projects and we have ensured that our teams include suitably trained and registered professionals, including environmentalists and Green Star SA Accredited Professionals.”

The four storey building, designed by MaC Architects, has been constructed on a podium covering a naturally-ventilated semi-basement of covered parking, with its orientation ensuring maximum indirect sunlight and reduced east and west direct sunlight.

Other green measures undertaken include: - A state-of-the-art air-conditioning system with a full economy cycle to provide free cooling when outside conditions are favourable - A state-of-the-art Building Management System which monitors and controls the energy consumption - Treated effluent irrigation and the harvesting of rain water for the flushing of toilets - High-performance glazing on the windows to reduce glare and radiant heat - The implementation of a “Green Lease”, believed to be the first in the country, in terms of which both the landlord and the tenant have undertaken to run the building as it was designed in terms of green building principles

Project 2: Aurecon Centre, Lynnwood Bridge Office Park, Tshwane A celebration of green-minded design and construction

Aurecon’s Lynnwood Bridge Office Park building, situated just off of the N1 highway, houses approximately 1 000 of its Tshwane staff and is a celebration of green-minded design and construction. These offices have recently been awarded a 4 Star Green Star SA - Office Design v1 rating by the GBCSA. Aurecon was responsible for all the engineering design disciplines on the project. Having gained vast

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PROFESSIONAL PROJECT PROFILE experience on similar projects, including Phase II of Nedbank’s head office in Sandton, which was certified as South Africa’s first Green Star SA building, Aurecon’s new offices in Lynnwood Bridge quest for green-minded design and construction resulted in a number of innovative green building initiatives being applied.

“From the onset, we knew it wouldn’t be an easy task,” comments Aurecon’s national green building expert, Martin Smith.

Conventionally, green buildings aren’t allowed to be built within 100 m of a wetland, yet the site allocated to Aurecon fell within 100 m of a tributary to the Moreleta Spruit, which is classified as a wetland of low ecological value. This led the entire project team to explore novel ways of ensuring storm water run-off from their building wouldn’t in any way harm the nearby spruit. The solution, consisting of various species of plants affixed to the building’s northern car park façade to act as a natural filtration system, is a first in South Africa.

Additional green innovations include: • Reducing the consumption of electricity – the building was designed with an energy efficient façade (consisting of high performance glazing, extensive external shading, and insulated wall panels and an insulted roof ) • Installing energy efficient light fittings with motion sensors • Reducing the amount of potable water supplied to and consumed by the building through water efficient plumbing fixtures, xeriscaping (making use of plants which require no water) and a rainwater harvesting system • Selecting building materials that minimise possible negative impacts on the environment • Improving the indoor environment quality for Aurecon staff by carefully monitoring CO² levels • Improving building design and management by monthly monitoring • Encouraging alternate forms of transport

Project 3: Shepstone & Wylie Office Development, Ridgeside Office Park, Umhlanga A sustainable building envelope

The Shepstone & Wylie Office Development situated in the prestigious Ridgeside Office Park in Umhlanga, KwaZulu-Natal, is the new head office for this prestigious firm of attorneys and was awarded a 4 Star Green Star SA ‘By Design’ accreditation by the GBCSA. This building has also recently been awarded a 4 Star Green Star SA ‘As Built’ rating.

As the green building consultant and mechanical engineer, Aurecon worked closely with the building architect to design sustainable climatic control elements. Energy saving designs have been implemented where possible, while the building also features a variety of ecologyconscious considerations, including waste recycling, the efficient use and recycling of water, irrigation and energy management.

Integration of ESD concepts from the inception of a project, through to design, construction, operation and decommissioning offer an opportunity to demonstrate whole life benefits for users of a facility and the wider community. Aurecon’s holistic approach to buildings facilitates the integration of sustainable development, civil and mechanical engineering, building planning and more efficient design to produce better building.

Contact Details:

Tel: +27 12 427 2000 Email: property@aurecongroup.com www.aurecongroup.com

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PROFESSIONAL PROJECT PROFILE

Riaan Steyn Architects House Van Huyssteen – Nautilus Bay, Western Cape Riaan Steyn Architects were approached to design and develop a new house inside the Nautilus Bay Coastal Nature Reserve. The development is just outside Mossel Bay in the Garden Route of the Western Cape.

The client, already owning a house inside the estate, needed the second house to push the boundaries of the estate’s contemporary Cape architectural style whilst still respecting the endangered fauna and flora. The latter emphasizing the importance for this house to be environmentally responsible.

The brief called for a house with a limited floor area combining large, comfortable open spaces with as much of the building’s external skin being able to open up and be flooded by southern views of the sites natural vegetation, dunes and sea front.

To achieve the most suitable sustainable objectives, identified throughout the planning phase of the project, the influence due to the site context, site location and project budget had to be kept in mind at all times.

Heat pumps for hot water requirements, underfloor heating and heating for the Jacuzzi were used, as opposed to solar geysers and solar collectors. The reason being the new house is mostly to be used as a holiday home, and the risk was too great for the solar collectors overheating the geysers due to long durations of not using it.

Due to the steep slope of the site this allowed for the position of a rainwater harvesting tank to be at the lowest point of the house, stormwater is then directed from all the different roofs and stormwater surface grids to the rainwater harvesting tank.

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PROFESSIONAL PROJECT PROFILE

Tasol Solar Solar Energy in Your Home

By Solar Academy of Sub-Saharan Africa (PTY) Ltd. Planning and building your new home or warehouse is the perfect opportunity for you to invest in a long term energy efficient solution which will not only save you money but allow you to generate free energy and contribute to a greener environment. By determining what your specific energy needs are, is your first step. There are energy consultants, such as TASOL SOLAR, who can assist you in sizing the correct systems to suit your requirements.

From basic domestic hot water systems to industrial grid-feed Photovoltaic systems, requires consulting your developer and energy consultant to discuss all the different elements which could play an important role. TASOL illustrates below some basic systems as well as niche applications to implement in todayâ&#x20AC;&#x2122;s domestic and industrial buildings. TASOL believes that energy savings in SA will be optimized in this way in the near the future.

Domestic Thermosiphon System - Small Scale

These systems work on the principle that when water is heated it gets less dense and rises to the top of the container. Colder, denser, water then moves in to the bottom of the container to replace the hot water. This process will continue as long as there is a sufficient temperature rise of the water to maintain this artificial pressure difference. There is no electrical circulation pump involved. These systems are very efficient andnormally cheaper than other systems. It is suggested to use a domestic heat pump as a back-up energy source rather than conventional elements, thus forming a hybrid solar system, which could save up to 90% of your hot water electricity bill.

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PROFESSIONAL PROJECT PROFILE

Approach to Sustainable Architecture and Urban Design Stauch Vorster Architects & Urban Designers encourages design as a collaborative process. Throughout the companyâ&#x20AC;&#x2122;s history numerous projects, characterized by their appropriate response to the environment, fulfilled the requirements of our clients and the public at large.

Stauch Vorster is committed to the imperative of sustainable urbanism and building design, taking into account the proven impact that urban systems and buildings have on local and global ecologies.

We aim to design healthy and low energyconsuming environments and buildings which respond to the environmental characteristics of the site. Our capacity to deliver in this regard is complimented by our competency in terms of SANS 10400Part XA : Energy Efficiency in Buildings, SANS 204 and our in-house accredited Green Building Professionals.

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PROFESSIONAL PROJECT PROFILE

We are committed to quality design which evolves out of establishing mutually beneficial relationships with each of our clients and to a continuous consideration for the impact of new projects on the environment, end-user and the public in general.

Through design excellence and dialogue we endeavour to develop appropriate and unique solutions for each project requirement. Understanding design as a people-focused endeavour, it is Stauch Vorsterâ&#x20AC;&#x2122;s mission to produce value, quality, and design excellence within the built environment.

Contact Details:

The Cape Waters Building 2nd Floor - Stauch Vorster Architects 71 Waterkant St (on the Fan Walk) Cape Town 8001 Tel: +27 (0)21 421 4276 Fax: +27 (0)21 425 1119 Email: capetown@svarchitects.com Website: www.svarchitects.com

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PROFESSIONAL PROJECT PROFILE

Nicholas Plewman Architects Project 1: Marataba Safari Lodge

The client required a predominantly tented but unique design to flagship the extension of a hitherto smaller luxury hotel brand. The site itself was unpromising but the views of the Waterberg are quite spectacular & the design evolved from the need to not only maximize but celebrate these views.

Project 2: Makanyi Lodge

The design departs from the practice’s current oeuvre to satisfy client requirements for a traditional “Zimbabwe” style organic plan. In doing so it indulges itself fully in a typical low veld lodge vernacular while providing an uncompromising level of luxury.

We delivered a full “turnkey ” ser vice including project management on demolition and remodeling of existing infrastructure, a new 16 bed lodge, power, water and fire reticulation and a DWAF approved sewerage system.

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PROFESSIONAL PROJECT PROFILE

Project 3: African Homestead In many ways this project exemplifies our work. It is both a homage to and critique of traditional South African architecture. The overall form and the materials used are familiar to almost all lodges but where the vernacular often seeks to insulate its inhabitants from harshness outside, the homestead embraces the surrounding bush and invites it in. Where in the vernacular materials are often, even deliberately, rough and ready; here these same materials have been finely wrought and applied with delicacy and finesse. As always our intention is make the relationship between the inhabitant and the surrounding bush as intimate as possible. This is achieved through glass, openness, a lateral plan form with courtyards and ponds that invite the bush to intrude into the hear t of the house and small “tricks” such as narrow decks and placing beds forward in the rooms, embracing the view. The lounge and dining room have practically no solid walls, the decks terrace to practically level with the ground in front and the pool licks out at the pan. Utmost care was taken to ensure zero ecological impact outside the confines of the building footprint.

The materials are hewn, spoke shaved, sanded or planed to reveal the rawness of the material. Rock is tumbled into gabions rather than pointed with cement. Gum poles are shaved to reveal the pale heartwood. Sandstone is honed. These refined materials applied to a simple orthogonal plan yield a clean cut, contemporary and un-clichéd home for luxurious but sustainable bush veld living.

Contact Details Tel: (011) 482 7133 • Fax: (011) 482 3170 www.plewmanarchitects.co.za

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PROFESSIONAL PROJECT PROFILE

OLIVER TAMBO NARRATIVE & ENVIRONMENTAL CENTREBENONI THE COMPLEX COMPRISES:-

• • • • •

Narrative Centre Environmental Centre Arts and Crafts workshops Amphitheatre Show House

LOCATION

The adjacent Leeupan is located in Benoni between the N12 to its north and the N17 to its south as well as being adjacent to – west of – the connecting Snake Road

THE INDIVIDUAL BUILDINGS

The central theme uniting otherwise disparate centres is the ecological connection with the environment. Each building utilises alternative technology and materials in its construction and servicing.

THE ENVIRONMENTAL CENTRE

This will be the centre of the complex from an education, information and management aspect.These three pavilions are characterised by mono-pitched roofs sloping down to the south; the facades at the ends of the buildings are angled to face north and south – the east and west walls are solid with smaller apertures. These buildings are naturally hot. In summer the temperature inside is controlled by heavily insulated straw-bale west and east walls as well as an evaporative cooling system

THE NARRATIVE CENTRE

The Oliver Tambo Museum will be linked by a walking trail to the near-by memorial at O.R.Tambo’s graveside. The building is naturally cool. During summer it benefits from being almost entirely surrounded by earth and enjoys the even coolness experienced, in underground caves. During winter however there will be a requirement for heating.

ARTS AND CRAFTS CENTRE

This part of the complex offers accommodation and facilities to artists and craftsmen in the community. The craftsmen will be able to: manufacture their wares; store them; permit visitors to view

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PROFESSIONAL PROJECT PROFILE them at work; and also display their crafts at the centre at organised events.

AMPITHEATRE

The final public facility in the complex is a 200 seater amphitheatre which takes advantage of the gradient on the site allowing the seating to cascade down the slope in the direction of the pan.

SHOW HOUSE (CARETAKER’S HOUSE)

Security and management of the complex will centre around a resident caretaker. The building is an environmental one bed-roomed house. The planning is informed by adapting Trombe Wall technology to the site conditions.

Trombe Wall technology is not commonly used in this part of the world; however the particular conditions of this site may enable this technology applicable.

The greenhouse-type lobby is fully glazed; capturing the heat from the Winter sun. The low sun rays strike the Rammed earth spine wall (through the glass) which acts as a heat sink; the wall absorbs the heat during the day, and at night that heat is released into the cool rooms.In Summer the Trombe Wall acts in reverse: external shades screen the entrance lobby from the suns rays during the day and therefore the wall is cooler than the exterior temperatures.

ALTERNATIVE TECHNOLOGIES

Other technologies investigated in the project include: • Cob wall construction • Concrete core tempering • Thermal mass earth floor • Rainwater Harvesting • Earthtube technology • Solar energy

CONCLUSION This Environmental Centre and complex is intended to function as a living laboratory for the benefit of members in the neighbouring communities as well as lay and academic visitors. It is to be a testing ground for familiar as well as lesser known sustainable systems.

Project commenced while project designer was Director in MMA

Contact Details Tel: Cell: Email:

+27 11 447 0737 +27 82 937 7734 tunde@odysseyarchitects.co.za

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PROFESSIONAL PROJECT PROFILE

Opportunities in gypsum housing venture Anglo American’s thermal coal business is looking for suitable partners to take its award-winning gypsum housing project from pilot phase to an on-going commercial venture that will benefit the environment and local communities.

The project is the most recent winner of the environmental category of the Nedbank Capital Green Mining Awards, which acknowledge the contribution that responsible mining and mineral beneficiation make to the economic development of Africa.

The initiative is centred on the company’s flagship eMalahleni Water Reclamation Plant, which eliminates the environmental challenges posed by rising underground mine water by turning it into pristine drinking water that is fed directly into municipal reservoirs in the critically water-stressed area. The plant currently meets 20% of the local authority’s daily requirements.

Construction has begun on the second phase of the facility which will increase its treatment capacity from a current 25 million litres of water a day (Ml/day) to 50 Ml/day. “eMalahleni has been identified as a growth node for the region and we are strategically positioned to provide the area with access to a clean and reliable source of water. Water is directly related to growth and development and without it neither industry nor communities can thrive,” says regional hydrology manager Peter Günther.

The unit operates at a 99% water recovery rate and the ultimate goal is for it to be a zero waste facility. This will be done through the complete utilisation of its byproduct – 200 tonnes of raw gypsum per day. With the expansion of the plant, this number will rise to a daily 600 tonnes.

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PROFESSIONAL PROJECT PROFILE

Two multi-million rand research and development projects have looked into uses for the byproduct, with one being its application in the building of affordable homes. This has been done extensively in the United States, Australia and Europe with much success. “A range of 24 different building products, including boards, fillers, panels and bricks can be made with this raw material,” says Günther, adding that gypsum may have an important role to play in South Africa’s credit-link affordable housing sector.

“We tested the technology in an employee housing project that involved the construction of 68 three-bedroom units in the KwaMthunzi Vilakazi Village, west of Witbank.”

Gypsum was used as a raw material for the production of bricks and the process was no different to the standard cement brick-making method. Fifty percent of the sand used for normal cement bricks was replaced with raw gypsum and the same procedure was applied for the plastering of the units.

Independent testing against SANS 1215 standards reveal that these bricks perform just as well as their cement counterparts and meet or exceed strength, shrinkage, water penetration and durability requirements. Therefore, no specialist equipment is needed and the houses themselves were built according to National Home Builders Regulatory Council guidelines for conventional brick and mortar construction.

“We are looking for business partners to take this project into a commercially viable communitybased venture with a strong preference for the employment of local labour,” says Günther. This is being done in conjunction with Zimele, Anglo American’s enterprise development arm.

Prospective partners can contact:

eMalahleni Water Reclamation Plant: Peter Günther (peter.gunther@angloamerican.com) or Thubendran Naidu (thubendran.naidu@angloamerican.com) Tel: +27 (0) 13 691 5450 Zimele: Lia Vangelatos (lia.vangelatos@angloamerican.com) Tel: +27 (0) 11 638 5425 www.angloamerican.com

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PROFILE

Rabana Architects Introduction

Rabana Architects is a firm of Architects, Planners, Project Management and Development Consultants with their head office in Midrand, Johannesburg. This practice is born out of the desire to contribute in the Reconstruction and Development Programme by providing our clients, both private and public, with the highest standards of design and service. A business adventure such as this should be seen in the context of a broad-based empowerment initiative. Rabana Architects will not only offer employment to young graduates but also create employment opportunities through large-scale development Projects implemented though our services. The stimulation of the economy through increased demand for building materials such as cement, bricks, steel, timber and many other related products, as a result of Building and infrastructure development projects cannot be over emphasized.

We are committed to the improvement of our physical environment through incorporation of the skills of Architecture, Urban and Landscape design. We desire to offer a service committed to design excellence, cost control from feasibility and inception to practical completion and to this end; we count on the invaluable support of both private and public sectors.

SCOPE OF SERVICES

1 Architecture Project Feasibility Studies: Strategic Briefing, Market research, Preliminary Scheme design, Preliminary Local Authority Submissions for approval.

Design Concept/Detail Design: Detail Scheme/Project design parameters and Impressions for Presentation to Committee or Investment Groups and other Management Structures. 3D design and Photo-realistic Presentations.

Project Documentation: Production of detailed tender and construction drawings, schedules, Specifications and other relevant Architectural documents. Co-ordination of other Consultants specialist input and documentation.

Contract Administration: Construction Supervision and Inspection of the Works and to ensure that the same Is in accordance with project documentation along with cost monitoring and control.

Evaluation of Existing Properties: Reporting on conditions of existing properties for

PROFILE purposes of sale, repair and/or extensions to maximise use of land and return on Investment.

2.2 Project Management The Group offers the above service as detailed hereunder: Project Control, Design Management, Construction Project Co-ordination, Cost Planning and Control Contract Selection, Progress Monitoring. Whatever the stage of development of the projects, We offer Project Management to ensure that projects do not get out of control, by planning and applying professional and proven management techniques.

2.3 Development Planning • Project Identification • Feasibility Studies • Project Conceptualisation • Project Capital Procurement • Public Involvement Co-ordination Programme 3. CAD The Firm uses Computer Aided Designing quite extensively, thus enabling a more rapid response to the client’s requirements and ensuring that accurate production information is supplied on schedule.

With CAD drafting capability we are able to produce the following: • Fast accurate drawings for presentation • Electrostatic plotting to any scale • Direct input of survey data • Automatic contouring and sections • Photo-Realistic 3D Colour modelling and Flythrough 4. MARKETING STRATEGY Rabana Architects will continue to promote itself by direct contact with potential clients, emphasising experience and expertise in management of largescale public projects as one of its strengths. We are encouraged and sustained in this development route by a policy of empowerment of marginalised consultants embraced by the Reconstruction and Development Programme.

It is our legitimate expectation that our quest to play a meaningful role in the re-construction of our country shall find support from progressive role players especially the public sector by giving us the opportunity to handle some of the projects earmarked for development.

Index of Advertisers COMPANY PAGE Africa Thermal Insulations

204

Aircare

8

Akisa Architects

86

Alive2green Sustainability Series

10

Alive2green Sustainability Week

1, Inside Front Cover

Anglo Operations Ltd

227

Arcelor Mittal

45

Association of SA Quality Surveyors

26

Aurecon

12, 218

BASF Holding South Africa (Pty) Ltd

42, Outside Back Cover

Belgotex Floor Coverings

122

Bluescope Steel Southern Africa

58, 212

Cape Brick

236

City of Johannesburg

32

Claybrick Association

164

CNCI (Cement & Concrete Institute)

154

Concrete Manufacturers Association

135

Corobrik

95

Crammix Bricks

18

Dimension Data

66, 176 the green building HANDBOOK

233

Index of Advertisers COMPANY PAGE Ergosystem

34, 210

Ettenauer SA

90

Eurolux

79

Fence It Manufacturer

188

Geberit Southern Africa (Pty) Ltd

40

Green Business Journal

146

Green Home Magazine

54

Group Five

120

ICI Dulux

116, 198

Italdoors cc

208

Jeffares & Green

238

Jojo Tanks

14

Kayema Renewable Energy

64

Lebone Engineering (Pty) Ltd

57, 98

M Tech Industrial

70

Magnastruct

20

Merensky Timber Limited

172

Modena Design Centres (pty) Ltd

28

Nicholas Plewman Architects

16, 224

Nicholas Whitcutt Architects

72, 232

234

the green building HANDBOOk

Index of Advertisers COMPANY PAGE Odyssey Architects SA (Pty) Ltd

82, 226

Peer Review Process

9

Perfect Places

192

PG Bison (Pty) Ltd

216

Plascon South Africa

2

Polymer Profiles

170

Rabana Architects

128, 230

Riaan Steyn Architects

160, 220

Robertson Ventilation Industries (Pty) Ltd

112

SA Vinyl Association

178

Safal Steel

4

Sasol Polymers Chlor Vinyl Business

240, Inside Back Cover

Screenline Africa

104

Shorrock Automation

152

Sika

6

Solahart

142

Stauch Vorster Architects

184, 222

Tal (Atmosphere)

52

Vela VKE Consulting Engineers

108

Vrede Textiles

196 the green building HANDBOOK

235

profile

Cape Brick Cape Brick is an innovative family owned and run Cape-based company that promotes sustainable development through the manufacture and supply of arguably the most energy efficient concrete products available. Established in 1938, Cape Brick is the longest running manufacturer of quality concrete masonry in operation in the Cape.

TThe companyâ&#x20AC;&#x2122;s comprehensive product range includes the standard masonry products such as all sizes of bricks and blocks, as well as the GreenLock range of retaining wall blocks and the BOBBLOK decking blocks. Cape Brick is known for its commitment to consistent customer service excellence and provision of the highest quality products to the market. The company is the only brick manufacturer that is an extensive supplier of environmentally friendly masonry with a minimum of 70% recycled materials in the Western Cape.

Both the materials and the production techniques that Cape Brick uses make for a product that has an extremely low embodied energy (the energy required to source the raw materials, manufacture the product and transport it to the site).

The bricks are made mostly out of recycled construction and demolition rubble which means that the company is not quarrying virgin aggregates and is therefore reducing the impact of

profile

mining on the environment. The practice of using these materials also eases the pressure on landfill sites where the rubble would otherwise end up. Cape Brick’s own waste material is reprocesses and all it’s products are all fully recyclable. The bricks are cured naturally and not baked. Baking uses large amounts of fossil fuel and releases greenhouses gases. All this leads to products that have the lowest embodied energy of any conventional masonry product available to the market.

Cape Brick’s decision to use recycled materials has resulted in the company saving the equivalent amount of energy needed to run 2000 medium income homes for a month. The use of these materials has also had a beneficial impact on the product quality as it offers higher compressive strengths than quarried materials at a similar price.

Not only do Cape Brick’s products have an incredibly low embodied energy but they are thermally efficient when used in conjunction with a cavity wall construction and ensure that buildings stay warm in winter and cool in summer. This saves money on any heating or cooling systems that would otherwise have to be used.

All of Cape Brick’s products comply with the SABS 1215 code for concrete masonry and the NHBRC, and are endorsed by the Concrete Manufacturers Association. All of this at no extra cost and no compromise in quality standards, while at the same time saving transport and manufacturing energy, reducing the mining impact on the environment, reducing the pressure on landfill dumping sites and promoting sustainable development.

Contact details Telephone: 021.5112006/7 Fax: 021.5102172 Email: sales@capebrick.com Web: www.capebrick.com Contact: Jaco Gildenhuys 074.1942044

We provide integrated Waste Management consulting services to clients throughout Africa Our team of highly qualified and experienced engineers and environmental scientists collectively combine to provide a service of exceptional quality in all fields of integrated Waste Management, bringing solutions to clients from Cape to Cairo.

tion to n e t t a LE pecial With s LE-TO-CRAD CRAD GEMENT… E… MANA WAST A S I E T G WAS Contact: Richard Emery on Tel: +27 (0)21 532 0940 HAVIN

Email: emeryr@jgi.co.za • Website: www.jgi.co.za

PVC - the specifiers choice for

sustainability and performance PVC, the polymer derived from a combination of common salt and hydrocarbon feedstock, finds wide acceptance across the building and construction industry. It uses less non-renewable fossil fuels and its products have low embodied energy compared to most other commodity plastics.

www.sasol.com/polymers

From pipe systems to cables, window frames, flooring and roofing materials, PVC products are recognised for their excellent performance in meeting and often exceeding sustainability and energy efficiency requirements easily complying to the new SANS 10400-XA regulations. Excellent recyclability of this material, complemented by its use in long lifespan applications, contributes positively to the conservation of the environment.

Pipes For proven durability, toughness and lightweight, thus enabling ease of installation. Resistant to corrosion, oxidative and chemical degradation.

Smooth interior walls enable ease of pumping, and coupled with low maintenance costs, offer low operational costs over the lifespan of pipe. Versatile, allowing for use in a wide spectrum of applications and designs. Best overall cost-performance ratio.

Window and door frames Ideal for conservation of energy in domestic and commercial buildings. Excellent ratings on energy efficiency achieved by rating agencies in developed markets. Require low maintenance and have superior durability. Offer a wide range of designs to meet architectural needs.

Cables Exceptional durability, excellent insulation and fire resistance properties. Good versatility enables suitability in a wide range of specifications and operating temperatures. Can be formulated for low

and high temperature use in various applications such as power transmission, domestic and industrial wiring, appliance wiring, automotive and telecommunication cables as well as information technology.

Flooring High durability, ease of cleaning and disinfection and therefore convenient for bacterial control and improved hygiene. Hence the preferred flooring material for health institutions. PVC flooring also requires low maintenance, hence lower life-cycle costs compared with other traditional flooring materials.

Ceiling Energy saving due to good insulation properties. Easy to clean and resistant to moisture, corrosion and rot.

Lightweight and therefore easy to install. Good fire resistance and durability make PVC ceilings ideal for domestic and industrial buildings. Can be designed to meet modern architectural requirements.

PVC has over the years evolved into a material of choice for building and construction through relentless efforts by the industry to address health and environmental impact of the product. Based on these achievements, the PVC industry is well positioned for the new challenges of sustainability that face all materials.

www.sasol.com/polymers