The Green Building Handbook Volume 5 by GreenEconomyMedia

www.greenbuilding .co.za

foreword

CSIR

outh Africa is experiencing challenging economic times and improving and providing infrastructure and service delivery to all people, and ensuring economic development, are key priorities of the Government. Recently the South African Government has launched the 18 strategic infrastructure projects (SIPs) initiative which are managed and coordinated at a macro programmatic approach. However, there are some fundamental resource constraints: South Africa remains with significant social infrastructure backlogs, the South African population is continuing to grow and energy and water constraints are looming. Finding innovative, resource-efficient (do-more-with-less) routes to growth is now an imperative. Similar challenges are to be found in the construction industry and the built environment in general: the industry remains challenged to deliver projects to quality and addresses the challenges of the green economy, in particular green buildings. Fortunately many successful innovative solutions exist, often residing within the CSIR Built Environment. The CSIR Built Environment is harnessing Research, Development and Innovation to improve construction processes, construction Dr. Cornelius Ruiters materials and methods, building performance, and to do it in Executive Director: Built Environment a manner that supports other Government imperatives, such CSIR as the Green Economy, job creation (especially for the youth), skills development and training, and innovative industrial competitiveness. Therefore, the CSIR Built Environment is continuing with its world class research in the following research themes: 1) Modular construction methods â&#x20AC;&#x201C; CSIR Built Environment has undertaken further research, development and innovation into modular construction with regards to the development of a new metric-based insulated hollow concrete block, and a structural insulated panel system using three components to construct a building; 2) Material technology â&#x20AC;&#x201C; CSIR Built Environment and Materials Science and Manufacturing is currently undertaking research and development into a range of bio-based composite building products, the greener brick initiative and cementitious replacement materials that will improve building performance, create new business enterprises, while reducing the environmental footprint of building materials in support of the Green Economy; 3) Modern Methods of Construction(MMC) â&#x20AC;&#x201C; utilising new building materials requires new ways of assembling these products and systems, including offsite manufacturing and onsite assembly, and BE is developing a manufacturing system for the erection of subsidised housing;

The green building handbook

CSIR

4) Smart buildings – developing an ICT Platform that can be used to monitor and continually adjust construction methods and progress and building components and systems to ensure that the building is operating at maximum efficiencies at all times; 5) Alternative Building Technologies (ABTs) – CSIR Built Environment is currently developing Alternative Building Technology systems to speed up social infrastructure delivery and performance (health clinics, schools); 6) Logistics – CSIR Built Environment has explored the implication of logistics in delivering buildings using Alternative Building Technologies and has found critical areas where logistical issues will significantly impede the use of ABTs in Government social infrastructure delivery programmes. Research, development and innovation in logistics is focus on energy minimisation in transport and supply chain management in sustainable human settlements, transport planning and freight logistics, i.e. green logistic. Projects completed by the CSIR Built Environment Unit in Mdantsane and Kleinmond have demonstrated the efficacy of mplementing innovative technologies to subsidised housing. The following benefits were demonstrated to be achievable: i) Material use – reductions of 26% in PVC use and 35% in building material mass in the Kleinmond Project ii) Water use – reductions in water used for construction and in operation in the Kleinmond Project iii) Energy use – reductions in electricity needed for manufacturing of construction products and for heating and cooling of the facility in the Kleinmond Project iv) Carbon emissions – reductions of almost 1 ton of carbon per subsidised house in the Kleinmond Project

foreword

to the construction of the super structure in the Kleinmond Project vi) Cost savings – the reductions in time and material translate into capital and operational cost reductions. The use of ABTs in a pilot projects undertaken by IDT showed cost reductions of up to 53% for school building projects vii) Improved construction quality. Thus, through the aforementioned world class research impact areas and completed projects, the CSIR is solving built environment problems and contributing towards the knowledge base of South Africa - and the world - and is instrumental in the management and transfer of this knowledge. These benefits from research, development and innovation are not necessarily confined to the subsidised housing market only but can accrue across the entire infrastructure sector by: viii) Improving and demonstrating improved competitiveness to construction industry stakeholders ix) Job creation – especially with regard to manufactured construction and green technologies x) Green economy – decarbonise the construction industry xi) Demonstrating the efficacy of innovation and alternative building technologies. Thus, in the context of the research development and innovation areas of the CSIR, the Built Environment unit it is pleased to endorse the publication of the Green Building Handbook Volume 5. 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 minimis ing and/or solving the major problems and con cerns in the construction and building industry.

v) Time use – saving of 1 day per house as a consequence of using a modular approach The green building handbook

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SAIA

foreword

y term of office as President of the South African Institute of Architects began in August 2012. In my Presidential acceptance speech I alluded to the fact that, like everyone else on the globe, we in South Africa are faced with challenges associated with changes in the climatic and weather patterns, which will continue to affect our built environment. These planet-altering shifts, together with unsustainable rates of resource-consumption by humankind, are placing our future on the planet at high risk. It is in this context that we state our aim as being the development of human settlements which are sustainable, humane, and inclusive. In seeking achievement of this aim we commit ourselves to engagement in economic activity which promotes responsible utilisation of biophysical, human and economic resources in the development of a sustainable future. However the achievement of these aims is not within the hands of architects alone. The challenges are complex and the solutions are multi-dimensional, systemic and intricately linked. Inter-disciplinary collaboration in the professional, technological, social and economic fields is the key to success. Amid the welter of information, disinformation, advocacy and denial, the Green Building Handbook series stands out as a trusted information resource for all those striving towards sustainability in the built environment. With the publication of this, the 5th Volume in the series, the focus moves towards achievement â&#x20AC;&#x201C; for instance, achievement of net zero energy and net zero water buildings. I heartily commend this and the preceding volumes of the Green Building Handbook to all practitioners in the built environment.

Sindile Ngonyama President South African Institute of Architects

The green building handbook

The

Green Building Handbook

South Africa Volume 5

The Essential Guide

SALES ADMINISTRATION Wadoeda Brenner PROJECT LEADER Louna Rae ADVERTISING EXECUTIVES Glenda Kulp, Tichaona Meki

EDITOR Llewellyn van Wyk CONTRIBUTORS Llewellyn van Wyk, Wim Klunne, Mauritz Lindeque, Dr Dirk Conradie, Green Building Council South Africa, Antoine Perrau, Mike Aldous, Riaan van Wyk, Tichaona Kumirai, Gordon Brown

CHIEF EXECUTIVE Gordon Brown

PEER REVIEWER Llewellyn van Wyk

DIRECTORS Gordon Brown Andrew Fehrsen Lloyd Macfarlane

LAYOUT & DESIGN Kurt Daniels

PRINCIPAL FOR AFRICA & MAURITIUS Gordon Brown

EDITORIAL & PRODUCTION Robyn Brown

PRINCIPAL FOR UNITED STATES James Smith PUBLISHER

ADMIN MANAGER Suraya Manuel DIGITAL MARKETING MANAGER Cara-Dee Carlstein

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

The Sustainability Series Of Handbooks

PHYSICAL ADDRESS: Wynberg Mews Cloete House Brodie Road Wynberg Cape Town South Africa 7824

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.

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PAPER TEL: 021 447 4733 FAX: 086 6947443 Company Registration Number: PRINTER 2006/206388/23 CHAPTER IMAGES www.greenbiz.com, www.freshpalace.com, www.forums.tf2maps.net, Vat Number: 4130252432 www.livinais.com, www.thenetworks.co.za, www.divorcelawyermedfordoregon.com, www.archdaily.com Endorsers:

THE GREEN BUILDING HANDBOOK

速

note

Editor

his Volume of the Handbook is, in many ways, indicative of the green building advances made in South Africa over the past 5 years. The first volume carried no local examples of green buildings – simply because there really weren’t any. Instead the Handbook addressed a range of issues located in the green building domain such as lighting, materials, indoor environmental quality, landscaping, and many others. But these were dealt with at a theoretical or principle level. In this years Handbook, Volume 5 of 2013, almost half of the chapters are case studies, only made possible because work has been completed in this field. Over the past 5 years the Green Building Council of South Africa has been launched and has developed and released green building rating tools for a number of building typologies. Buildings have been certified, and from these, evidence collected of the benefits accruing to building owners, occupants, and the country at large. Architects are able to report on outcomes of the design approaches they have adopted in achieving a green building, and can begin to quantify the performance enhancements gained through the adoption of those design strategies. Antoine Perrau reports on two of the projects his practice has completed in Reunion, a climatic zone presenting real challenges to passive design. Increasingly the South African Government is also requiring green buildings as a prerequisite for new build as well as for leasing: this is a very encouraging sign. The engineering consulting firm PDNA reports on the design approaches adopted by the client and professional team in the chapter featuring the new office building for the Department of Environmental Affairs (DEA), surely one of the ministries most required to demonstrate leadership in this field. Owners too are able to report on their experiences, and often, as is the case with the Detnet Building included in this Volume, provide a wealth of information and experience that everyone will benefit from. This shift in the market has opened up new fields of enquiry, most notably in building simulation: in addition to the application of building simulation in the DEA Building, two chapters are the result of simulating building performance namely, Tichaona Kumirai’s study on indoor thermal comfort in a typical school classroom, and Dirk Conradie’s study on the efficacy of various passive design strategies when applied to the different climatic zones of South Africa. This work is based on very recent

research into categorising current climatic zones in South Africa, as well as developing an understanding of potential future climate change impacts and how that may impact on building performance. Lastly the Handbook deals with a new movement gaining traction across the world namely the Net-Zero Movement. Currently being driven by a desire to reduce the dependence of a building on grid-supplied energy, the net-zero movement is slowly moving into other critical performance areas including net-zero water and net-zero waste. Three chapters deal with this movement with particular regard to net-zero energy, net-zero water, and a netzero building incorporating those three categories plus net-zero emissions (GHGs as well as sanitation waste) and net-zero ecological loss. It is becoming quite clear that the green building movement has picked the low hanging fruit and that any further significant advances now will depend on major technological breakthroughs. This is equally true for the building material manufacturers. There are encouraging signs in this regard: the emergence of biocomposite materials (strongly supported by the aeronautical and automotive industries) hints at a new generation of materials based on renewable resources, while the breakthroughs occurring with regard to renewable energy technologies suggest that renewable energy may soon be able to generate the amount of energy required to manufacture materials let alone operate buildings. If this Handbook is indicative of the advances made in the past five years, I cannot wait to see what gains will be made in the ensuing five years. Stay with us for that journey. Yours truly, Editor The green building handbook

contents Chapter 1: Net-Zero Building Llewellyn van Wyk

Chapter 2: Net Zero Energy Wim Klunne

Chapter 3: Net Zero Water Mauritz Lindeque

Chapter 4: Passive Design Strategies Dr. Dirk Conradie

100

Chapter 5: It Pays To Build Green GBCSA

124

PROFILE

www.plewmanarchitects.co.za Tel: 011 447 3414 • Fax: 087 942 3551 THE GREEN BUILDING HANDBOOK

contents Case Studies

Chapter 6: Designing in the Tropics

138

Chapter 7: Department of Environmental Affairs New Head Office

162

Chapter 8: DetNet Building

180

Chapter 9: Building Thermal Loads

202

Chapter 10: Net Zero Waste

224

Antoine Perrau

Mike Aldous

Riaan van Wyk

Tichaona Kumirai

Gordon Brown

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 explor ing the dynamic oppor tunities of modernism and technology

www.duluxtrade.co.za

Tomorrow’s Answers Today With headquarters in Amsterdam, AkzoNobel is a Global Fortune 500 company, the largest global paint and coatings company worldwide, and a major producer of specialty chemicals.

To this end, sustainability informs what we do and how we do it.

Our portfolio includes world-renowned brands such as Dulux, Sikkens, Dulux Trade, Rockgrip, Fix It, International and Eka.

Proudly ranked within the top three chemicals companies in the world according to the Dow Jones Sustainability World Index, we continually evaluate our environmental and social impact as we deliver future facing products. We strive to deliver “Tomorrow’s Answers Today” by:

Our iconic brands are manufactured and distributed from operations in more than 80 countries and across 5 continents. Driven by our vision for future-perfect products. We offer practical solutions with minimum environmental impact. With scale comes responsibility. And as the largest player in the paint and coatings industry, we understand our role in meeting the needs of the present without compromising the ability of future generations to meet theirs.

Product design, raw material selection, manufacturing and the way we interface with people and their communities is considered as we strive to deliver “Tomorrow’s answers today”.

Focusing on our customers’ future first Embracing entrepreneurial thinking Developing the talents of our people Having the courage and curiosity to question Acting with integrity and responsibility in our actions Setting high standards In so doing, every day, our decorative portfolio of brands and products add to the aesthetics of projects around the world. Adding mood, colour and protection to the commercial and residential buildings in which people work and live.

ACCREDITATIONS

ISO 14001 ISO 9001 OHSAS 18001 These accreditations are audited annually. ACHIEVEMENT HIGHLIGHT

AkzoNobel has cemented its position as a global sustainability leader after being ranked in first place in the Chemicals supersector on the prestigious Dow Jones Sustainability World Indexes (DJSI) The latest listing reveals that AkzoNobel achieved a total score of 93, improving on last yearâ&#x20AC;&#x2122;s second place. The company has been ranked in the top three since 2007 (when AkzoNobel last topped the list). Akzonobel is also listed on the FTSEGood Index. Dulux is a proud level five B-BBEE contributor.

Net-zero building

chapter: 1

Net-Zero Building

Llewellyn van Wyk Built Environment Unit CSIR, Introduction In its experimental work on the research and development of innovative technologies for low income housing on the Innovation Site on the CSIR Campus in Pretoria, the Building Science and Technology (BST) competence area identified a number of interventions where innovative technologies could realise substantial building performance improvements. A central challenge to construction and building performance is located in the practice of constructing a building on the project site using a combination of raw materials, semi-raw materials, and finished materials employing a number of tradesmen, skilled and unskilled. A further challenge with conventional construction materials arises not so much from limited supplies (construction materials are generally drawn from some of the Earthâ&#x20AC;&#x2122;s most abundant resources) but from the energy required to process those raw materials and the consequential environmental degradation associated with its extraction and refinement. The Case Study The design and construction of a bio-based, resource-efficient, intelligent and ecological demonstration building seeks to assess whether adopting new construction materials and methods would result in substantial building performance improvements while reducing its ecological footprint. This chapter describes the process followed in the design of the demonstration building. In doing so it uses a research-based approach to design where the design of the demonstration building is not a consequence of a preconceived form or style but emerges out of the findings of the research. The building is to be used primarily as a demonstration facility: in this capacity it will host exhibitions of bio-based materials, meetings associated with the bio-composite industry, and provide research facilities for researchers and scientists associated with bio-composite building materials and products. The Goal of the Project The project entails the construction of a bio-based, resource-efficient, intelligent, ecological demonstration building as an interactive experiment where ongoing research and development (R&D) can be applied to monitor, evaluate, and demonstrate the: a) Application of bio-composite materials in construction, and b) Application of new plug-and-play systems for the envelopes of buildings including the widespread use of sensors, novel construction methods, and utility control software; c) Potential for buildings to be designed and constructed in a manner that supports resilience, i.e., is both adaptive to changing environmental conditions, and mitigates the buildingâ&#x20AC;&#x2122;s impact on ecosystems. The green building handbook

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.

ENERGY

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

TRANSPORT AND TRAVEL

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

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.

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

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

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

At Dulux we are committed to reducing waste from our manufacturing process. Our manufacturing facility in Durban has installed an on-site recycling center that reuses our manufacturing waste and we are also engaged with a recycling company to manage the balance of our waste on site. There is also a focus on onsite effluent water reuse into paint production coupled with a planned rainwater harvesting systems to reuse rainwater into paint production in order to reduce our dependency on potable water.

Net-zero building

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The goal of this project therefore is to develop 3rd Generation construction materials and methods using green technologies to make buildings more sustainable, more resilient, improve indoor environmental quality, use less non-renewable resources, be adaptable, and display improved overall performance. In order to achieve this, the secondary goals are to: • Reduce the buildings dependence on municipal services • Reduce the buildings impact (footprint) in the site both during construction and operation • Reduce operational resource requirements • Improve quality through the use of modular systems • Simplify construction processes and methods to reduce construction time • Demonstrate proof-of-concept for new technologies Approach to the Research The strategic rationale of the project remains as stated in previous research studies, namely: The Advanced Construction Technology Platform (ACTP) aims to undertake R&D into material, production, and assembly technologies in order to develop and sustain a construction manufacturing capability in the construction industry of South Africa in pursuit of delivering enhanced building performance and delivery that support sustainable and resilient human settlements. Research-based Design The conventional method used for design is best illustrated in the ‘Practice Manual of the South African Institute of Architects’. The generation of a design as proposed in the Standard Services includes the following two Stages (SAIA 1.211:3): Stage 1: Appraisal and Definition of the Project Receive, appraise and report on the client’s requirements with particular regard to site information, planning and statutory regulations and budget. Stage 2: Design Concept Advised by any consultants appointed, prepare a design concept in broad outline showing intended space provisions, planning relationships, materials and services intended to be used. It may be argued that the two sections imply a research-based approach to design, however the text is biased towards meeting the programmatic goals of the client rather than researching and testing the full range of performance requirements of the building projects. By contrast Ernst Neufert: Architects’ Data (ed. Herz, 1970) suggests an approach closer to researchbased design as it is proposes a qualitative and quantitative research method, now known as ‘mixed method research’. In the section appropriately titled ‘Design Method’ (Herz, 1970:30) it is recommended that the ‘work starts with the preparation of an exhaustive brief’ and lists information that must be known before planning begins. A questionnaire is included in this approach which includes questions relating to the client, fees and agreements, persons and firms connected with the project, general, project, basic design factors, technical fact finding, records and preliminary investigations, preliminaries, and activities and events. The question is a combination of quantitative data (e.g., type of topsoil) and qualitative (e.g., what is the attitude of the town planning officer towards architecture). It then recommends that the individual units are analysed, drawn to scale and put provisionally into groups and the relationships of rooms to each other and to the sun is analysed (Herz 1970:30). What follows is critical: ‘at this stage an idea” in 3-dimensions will emerge’ and ’instead of starting to design The green building handbook

a greener future

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Net-zero building

chapter: 1

at this stage, explore the various means of access, the prevailing wind, tree growth, contours, aspect, neighbourhood, then finalise the positioning of your building, relating it to tentative landscaping, etc.’ Finally, it recommends that one ‘try out several solutions to explore all possibilities and use their pros and cons for searching examination.’ Based on the foregoing it argues that the ‘idea now becomes clearer and the real picture of the building emerges’. Mixed Method Research What is described in Neufert’s text is grounded theory, a quantitative research method that aims to allow the theory (in this case the idea) to emerge from the research. In fact, an early attempt to ‘design’ is discouraged to allow theory testing to be done from which a ‘design’ emerges. Further evidence to support this theory is found later: Neufert recommends that after the completion of the preliminary design a pause is taken to ‘help get rid of preconceived ideas and undigested brain-waves, and to allow time for other short-comings of the design to be revealed not least in discussions with staff and client’ (Herz 1970:30). To further aid this research method Barry’s Introduction to Construction of Buildings (Emmitt and Gorse, 2005) is used to construct a useful methodology for considering the construction of buildings by breaking the construction process down into five basic components, namely; sub-structure, superstructure, roof assembly, services, and finishes. Each of these components can be further sub-divided into sub-components such as windows and doors for super-structure. This approach has been used with some success in previous experimental studies undertaken by the CSIR at its Innovation Site in Pretoria (van Wyk, 2009; de Villiers 2011). Delimitations to the Project The following limitations and delimitations apply to this chapter. Limitations (weaknesses) i) The facility, while being usable, is not intended to be occupied on a full-time basis. Delimitations (exclusions) i) For purposes of this chapter the research work focusing on the development of biocompositebased construction products is excluded. ii) Although reference is made to the use of wind energy, at the time of undertaking the study a suitable system could not be identified. Further research is underway to design a bespoke wind turbine system to supplement the PV panels. The Research Questions and Sub-questions How and in what way can Science, Engineering and Technology (SET) be used to design and construct a usable building that will demonstrate the application of bio-composite construction materials and products, while delivering improvements in indoor environmental quality, reductions in non-renewable resource use, improved construction quality, and support resilient human settlements in a sustainable economical manner? The research question informing the study is thus as follows: Seven sub-questions were developed, of which only the following four are described in this chapter: Sub-question 1: What are the conditions under which a building contributes to strengthening resilience? Sub-question 2: What bioclimatic conditions influence the performance of the building? Sub-question 3: How, and in what way, can the building be made independent of municipal services in a cost effective manner? The green building handbook

Net-zero building

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Sub-question 4: Applying the quantitative and qualitative data from sub-questions 1-3, what â&#x20AC;&#x2DC;ideaâ&#x20AC;&#x2122; of the optimum building form and envelope emerges that can be used as the basis for testing? Strengthening Resilience: The Environment/Building Nexus Resilience is the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and recovering quickly. Perturbations and disturbances can be caused by a number of natural and anthropologically-driven events including climate change. Events of sufficient magnitude may force an ecosystem to reach a tolerance threshold beyond which a different regime of processes and structures predominates It is now understood that human activities can also result in perturbations and disturbances: these would typically involve a reduction in biodiversity (through agricultural practices for example), the exploitation of natural resources, pollution, and land use. In the same vein, anthropogenic contributions to climate change will also contribute to perturbations or disturbances which could push ecosystem tolerance levels to critical thresholds. However, the application of resilience theory to cities is problematic as in nature systems are able to regenerate themselves, something human settlements cannot do. The more convincing description for resilient cities is a city that enhances resilience through the application of practices that support ecosystem health, that strengthen ecosystems under threat, and that reduce anthropogenic contributions to global warming. Two strategies that buildings can implement are: i) Replace what is displaced (mitigation), i.e., zero impact both on biodiversity and from land-use changes, resource exploitation, pollution, greenhouse gas emissions; and ii) Reduce vulnerability to impacts (adaptation), i.e., recalculate design loads, analyse local climate change impacts (flooding, winds, storms, precipitation) and design to avoid damage, and reduce dependence on municipal services. Bioclimatic Conditions and Building Performance Geographical location is a significant determinant of building performance: climatic conditions, ground conditions, and indigenous flora and fauna, differ from place to place and so influence both the qualitative and quantitative qualities of a place. Site description The site is located on the property of the CSIR in Port Elizabeth which is located on the eastern coast of South Africa (see Figure 1).

Figure 1: Location, CSIR, Port Elizabeth

The green building handbook

Net-zero building

chapter: 1

Climate Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, precipitation, atmospheric particle count and other metrological elemental measures in a given region over long periods. Climates can be classified according to the average and the typical ranges of different variables, most commonly temperature and precipitation. Port Elizabeth has a sub-tropical climate with rain falling throughout the year. According to the Koppen climate classification Port Elizabeth has an oceanic climate. This climate generally features warm, but not hot summers and cool, but not cold, winters, with a narrower annual temperature range than experienced in comparable latitudes. It typically lacks a dry season as precipitation is spread more or less evenly over the year. Climate can generally be defined as the weather averaged over a long period: the Intergovernmental Panel on Climate Change (IPCC) glossary definition is: Climate in a narrow sense is usually defined as the â&#x20AC;&#x153;average weather,â&#x20AC;? or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system .

Figure 2: CSIR Koppen-Geiger Map The green building handbook

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Net-zero building

Temperature Table 1 depicts annual temperature for Port Elizabeth.

Table 1: Monthly and Annual Temperature Ranges for Port Elizabeth As can be seen the temperature generally ranges between 6 °C and 26 °C although extremes of 2 °C and 31 °C have been recorded. More critically if the ideal indoor temperature range of 21 °C to 27 °C for summer and 20 °C to 24.5 °C for winter is considered (UCT 1979), it is evident that cooling should not be required but that heating will be required. Precipitation The average annual precipitation for Port Elizabeth is shown in Table 2 below. The annual average for Port Elizabeth exceeds the annual average for South Africa. In addition, precipitation occurs almost evenly across the year which will contribute greatly toward the efficacy of rainwater harvesting.

Table 2: Annual Precipitation for Port Elizabeth Humidity Acceptable relative humidity levels vary: Herz (1975:19) suggests a range of 50 – 60 per cent is the most comfortable whereas a range of 20 – 76 per cent is suggested by UCT (1979). 32

The green building handbook

Net-zero building

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Figure 3: Climate Graph, Port Elizabeth As can be seen from Figure 3 , the relative humidity in Port Elizabeth ranges from 74.5 to 81.8 per cent, levels which breech the upper levels of acceptability as suggested by Herz and UCT. To counter this, two strategies are proposed. The first is to increase ventilation rates, and the second is to provide some porous surfaces internally. Ventilation rates are addressed later and various strategies are proposed to improve natural ventilation. Porous surfaces are proposed for the central core of the building to create a degree of thermal mass for thermal comfort purposes, and this same material can contribute towards lowering internal humidity levels. Wind Data gathered from weather files for Port Elizabeth depicts the predominant wind direction is from the south west, i.e., at an oblique angle to the building. The wind direction is almost constantly south west with only slight deviation towards west from March through to August (see Table 3). When wind is blowing against a building, the straight motion of the air is disturbed and deflected around and above the building. If the wind direction is oblique, the two upward sides are under pressure and the others under suction (Givoni 1969). Givoni notes that the roof is subject to suction at all times. With an oblique wind there is also a sharp drop in pressure from the wind ward to the leeward corners. At an angle of incidence of about 45 the pressure at the downward corners almost disappears. The green building handbook

chapter: 1

Net-zero building

When openings are provided at points subjected to pressure difference, airflow is initiated between them. The greater the pressure differences the higher the rate of airflow through the building: when the windows are closed the pressure difference determines the rate of airflow by airfiltration. This pressure distribution can be used to induce cross-ventilation even in rooms with one extended wall.

Table 3: Wind Direction and Speed for Port Elizabeth

Achieving Municipal Service Independence One of the strategies that can be employed to build human settlement resilience is to minimise exposure to municipal service failure arising out of natural and man-made disasters. Storm damage often destroys power lines, water services, and sanitation services. Thus reducing the buildings dependence on municipal services by providing as much of the services on site will enable the building to continue operations in the event of major perturbations and events. The provision of municipal services is also a contributing factor in perturbations and events, especially those created by climate change. A strong nexus exists between municipal service delivery and energy: water treatment and supply, sanitation treatment and supply, and storm water collection and distribution all require electricity to power treatment works and pumping stations. Thus the provision of municipal services on site is a mitigation strategy which, in turn, builds resilience. Electricity It is intended that all the power required to operate the building should be generated on site allowing 34

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the building to function off-grid. Two systems can be used for generating renewable energy, namely photovoltaic panels (PVP) and wind turbines. The design of the building must be informed by the best orientation towards the sun to optimise for solar energy yield. A “solar roof” will be used to generate hot water by means of solar water heaters and electricity by Photovoltaic panels (PV panels). PVP Photovoltaics (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material. Materials presently used for photovoltaics include monocrystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium gallium selenide/sulfide. Due to the growing demand for renewable energy sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years. Designing photovoltaic systems requires consideration of the following factors. System’s analysis The system’s analysis focussed on the solar PV component of the project by first analysing the energy requirements of the building in order to design a solar system that would be able to sustain the electricity demands. In that analysis consideration was given to the fact that days with limited solar radiation do occur and battery storage is required to bridge the periods when no sun shine is available. Typically a three days’ autonomy is the industry norm when designing PV systems. Available solar radiation Maximum solar yield will occur when the incoming solar radiation is perpendicular to the receiving surface. Due to the variation in the position of the sun over the seasons, the required angle for the receiving surface will change accordingly. The optimal angle during winter periods is 49˚, while in summer 19˚ is optimal. For fixed surfaces, a yearly average of 34˚ can be used. See figures below for details. Port Elizabeth Average Solar Insolation figures Measured in kWh/m2/day onto a solar panel set at a 34° angle: Table 4: Average Solar Insolation Figures for Port Elizabeth

Solar orientation Based on the optimal angle of the receiving surface, a North-facing roof should be designed with an angle of 34˚. Calculating demand The design demand should be calculated on maximum demand if the building is being fully utilised at the same time. Based on an analysis of the expected demand for electricity, a load profile was generated using the expected utilisation of appliances. It was assumed that the four work cubicles would each have one laptop running for the full working The green building handbook

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day of 8 hours. Four desktop computers would be in continuous use for monitoring purposes of experiments being carried out on the building shell. Lighting was assumed to be with 35 energy saving CFL lights, illuminating all internal and some external areas of the building. The water pump was assumed to be running for 8 hours per day, while the kettle and micro wave oven in the kitchen were assumed to be used regularly as well. In addition allowance was provided for a small fridge. The table below represents on overview of the expected electricity demand in the building.

Table 5: Expected electricity demand Based on the expected electricity demand a design exercise was done to have a matching electricity supply system. If the system is designed assuming full autonomy from the electricity grid allowance needs to be made that the system can supply the maximum simultaneous electricity demand expected and will be able to do so for three consecutive days without significant solar radiation. Correct sizing The electricity consumption in the building was estimated at approx. 38.5 kWh / day. Assuming losses in the electricity system of approx. 15%, the solar system needs to be able to supply around 44.5 kWh per day. Using typical parameters on solar radiation for Port Elizabeth as per tables below, 40 solar modules of 240 Wp are required. Given the size of these panels, a roof space of 66 m2 is required to make the building totally autonomous.

Table 6: Daily Power Requirement

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A more critical look at the conditions set for the building it was decided to design the electrical system in such a way that the building will become nett energy neutral by using the available electricity network on campus. In period of high electricity demand and during overcast days, the building will rely on the local electricity grid to augment the solar system, while, at periods with abundant sunshine and/or low demand, electricity will be fed in the campus’ grid. The typical load pattern of the PE campus with mainly offices and day time electricity demand matches very neatly with the electricity production characteristics of a solar PV system (only electricity production during daytime). Applying this thinking to the solar system, nett electricity neutrality can be achieved by a typical 4.8 kWp system. Water Water conservation includes rainwater harvesting and treatment, and waste water recycling systems. Water conservation requires consideration of the following factors. Water Harvesting Rainwater harvesting involves the collection and storage of rainwater from the roof of the building. System analysis The water is collected and stored in rainwater tanks: the tank or tanks can either be positioned on the ground close to the downpipes or in a single more ideally situated location, or buried in the ground as a subterranean tank. Calculating demand The water demand calculator as used in the Code for Sustainable Homes (2010) of the UK was used to calculate water demand per person. The following data was entered. Taps – flow rate 6l/m based on Cobra Gala taps fitted with a restrictive aerator. Water demand per person – inserting the flow rate and number of fittings (1 mixer in each bathroom and 1 mixer in each kitchen) into the calculator resulted in a total demand of 35l/p/day. No provision is made for urinals and the water closets (wc’s) are based on closed-system units (see sanitation section). Number of persons – it is assumed that 2 people will use the facility each day of the month, with one meeting of 15 people per month, and two days where 5 people will use the facility per month. Total water demand = 2 485 l/m. Correct sizing To calculate the number and size of water tanks required the following calculation was used (Worm and Hattum, 2006). Area of roof = 109.90 square meters Runoff co-efficient = 0.9 (sloping roofs) Supply = Rainfall x Catchment Area x Runoff Co-efficient

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Table 7: Rainwater Tank Sizing In determining the total tank size, the monthly demand was taken plus the surplus from November to provide a safety factor to carry the facility over the drier months of December and January. A total tank capacity of 4 826 litres, or 4.8 cubic meters is required. Since the design allows for four tanks, each tank must hold 1.2 cubic meters (12,000l). Installation requirements The rainwater is to discharge into correctly sized rainwater gutters, and each tank is to be supplied with a downpipe. A leaf catcher together with a cloth (natural fibre) filter is to be provided to each downpipe before the water enters the tank. An overflow pipe is to be provided to each tank at the same height as the entry pipe in case of a severe downpour. Ideally the tanks should be placed above the ablution facilities to enable gravity feed to the fittings: a reinforced concrete slab will be required to support the water tanks. Heating and Cooling Heating (water and space) and cooling (spacing) are two requirements that are energy consumers. Water heating is a standard requirement in building although the demand for water heating in this specific project is limited to water for kitchen purposes only. The bioclimatic data indicates that space cooling should not be required, but that space heating will be required. Water Heating South Africa has some of the highest solar radiation levels in the world which supports the use of solar water heaters to supply the hot water. The green building handbook

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System’s analysis In general a solar water heater will consist of the two following components: • 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. • 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: • The thermosyphon system makes use of the natural tendency of hot water to rise above cold 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. • 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 timer and thermostat to provide auxiliary heating during days with limited solar radiation or when all hot water has been consumed. In the situation of the building concerned in which 1) hot water availability is non-essential and 2) we would like to minimise energy consumption, it is proposed to install a thermosyphon system without back up element . Available solar Maximum solar yield will occur when the incoming solar radiation is perpendicular to the receiving surface. Due to the variation in the position of the sun over the seasons, the required angle for the receiving surface will change accordingly. The optimal angle during winter periods is 49˚, while in summer 19˚ is optimal. For fixed surfaces, a yearly average of 34˚ can be used. Orientation The design of the building was informed by the best orientation towards the sun to optimise for solar energy yield. Based on the optimal angle of the receiving surface, the North-facing roof has been designed with an angle of 34˚. Calculating demand The demand for hot water in the building is limited as there are no shower or bathing amenities provided. Hot water will only be required in the kitchen. However, it is proposed to use solar water heating to heat the building in winter. Correct sizing The recommendation is to install a 300 litres indirect solar water heating system with flat plate collectors. The recommended size of the storage tank will ensure enough hot water storage capacity 42

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to bridge overcast days. A system with flat plate collectors is suggested as these will have a better visual fit with the solar PV panels than the alternative of vacuum tubes. Sanitation The term “sanitation” refers to the principles and practices relating to the collection, removal or disposal of human excreta, household waste water and refuse as they impact upon people and the environment (DWAF, 2002). Sanitation is any system that promotes sanitary, or healthy, living conditions. It includes systems to manage wastewater, storm water, solid waste and household refuse and it also includes ensuring that people have safe drinking water and enough water for washing (DWAF, 2002). The basic purpose of any sanitation system is to contain human excreta (chiefly faeces) and prevent the spread of infectious diseases, while avoiding danger to the environment (Austin & Duncker, 2002). Sanitation includes both the ‘software’ (understanding why health problems exist and what steps people can take to address these problems) and ‘hardware’ (toilets, sewers and handwashing facilities). Together, they combine to break the cycle of diseases that spread when human excreta and waste are not properly managed. Sewerage Treatment There are a number of technologies that can be used for sewerage treatment. The technologies most commonly used in South Africa are summarised below. Ventilated Improved Pit (VIP) toilets, correctly engineered and implemented, are a good means of providing a dry sanitation service, but these systems are not without their problems. Hard or rocky ground makes the choice of this technology inappropriate. Non-cohesive soils require a pit to be lined in order to prevent collapse of the structure. Pits should preferably also be avoided in areas with shallow groundwater. These toilets are also unsuited to densely populated urban or peri-urban environments. Full pits are a further problem: in most cases the owners cannot afford to empty or rebuild them, and under-resourced, under-funded local authorities experience enormous difficulties in performing this task (Austin & Duncker, 2002). Ecological sanitation is a system that turns human excreta into something useful and valuable, with minimum risk of environmental pollution and no threat to human health. It is a sustainable closedloop system that treats human excreta as a resource, not as a waste product. Excreta are processed until they are free of disease organisms. The nutrients contained in the excreta may be recycled and used for agricultural purposes (Austin & Duncker, 2002). If such a dry toilet (i.e. not requiring water for its operation) is designed and constructed in a way that the faeces vault can be quickly, easily and safely emptied, and if the processed excreta can also be productively and safely used for agriculture, the technology is even more attractive, especially where rural communities rely on subsistence agriculture, often in poor soils. Water-borne sanitation is the preferred sanitation option in South Africa due to the perceived ease of use and maintenance by the users. The cost and maintenance of a centralised sewer system and treatment works are not considered as part a household’s sanitation chain. Any other type of sanitation technology requires daily effort and costs in terms of operation and maintenance, and users have to undergo intensive and repeated training (i.e. it is not a flush-and-go). System’s analysis An on-site, closed-loop system, flush toilet waterborne sanitation system is available from New World Sanitation and Solar Solutions (Pty) Ltd. Naturally-occurring micro-organisms (bacteria) are selected as a biological additive to the digester tank of the self-sustainable flushable, portable and/or fixed biological water-borne toilet. The biological process occurring in the digester tank converts raw sewage into re-usable filtered water, ready for re-use to the toilet cistern for flushing. The green building handbook

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The principle is that naturally-occurring micro-organisms as opposed to chemical possesses, are selected as a biological additive to the digester tank of the self-sustainable flushable, portable and/or fixed biological water-borne toilet. The biological process occurring in the digester tank converts raw sewage into re-usable filtered water, ready for re-use to the toilet cistern. Rain water collection further minimise load on external water sources. The flow pattern design is what makes the SMARTSAN digester concept so unique. The flow pattern creates a combination of anaerobic as well as aerobic digestive properties. This creates the environment for the right types of bacteria to survive and grow to ensure a natural biological breakdown of raw sewage into reusable grey water. It creates a biological breakdown process to cover all the basic working concepts of a conventional sewer plant in +/- 1.3mÂł with a relative small footprint of +/- 2.16mÂ˛. When the digester unit is installed it gets filled with water completely. This ensures the unit will have hydraulic flow between the different tanks whenever the toilet is flushed (+/- 3 liters per flush). It also enable for the aerobic zones to be created immediately via the recycle pump system. Normally the system balance itself out that there is no excess water. The adding of water to the system through urine and the evaporation of water due to the circulation of the system keep the system at a constant level. Should excess water accumulate in the system due to rain, bath and kitchen water an over flow line (18) is fitted to the system that flows into a bio-mat(19) installed in the ground away from the system to ensure that the ground surface around the system stay dry (see Figure below).

Figure 4: SMARTSAN System by New World Sanitation Calculating waste volume The waste to be treated comes from two (2) water closets (WCs), two (2) hand wash basins, and one (1) kitchen sink. Correct sizing A single digester will be sufficient for the requirements of this building.

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Installation requirements The product can be supplied as a pre-assembled unit or it can be supplied in a kit form to be assembled on site. This will make the transport of the unit much easier and no heavy equipment will be needed for installation. The parts can easily be handled and carried by hand. The top structure is moulded double-sided causing it to have a cavity wall. The purpose for the cavity is to form a sealed tank. The roof of the top structure is designed in such a way that it will collect rainwater into the top section of the top structure for cistern supply water and into the middle section of the top structure to supply the hand wash basin with clean water for hand washing. Each toilet unit has a hand wash basin as a standard feature. On the roof is also fitted a solar panel which supplies power to the recycle pump in the digester unit. Payback period It is not possible to calculate the payback period at this time: once the full system design is completed the payback period can be calculated. Typical costs are provided as a guideline only at this time.

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Generating the Idea Conceptual Development In developing the initial concept, the following was taken into account: • Programmatic requirements for the building • Climatic conditions of the site • Net zero performance characteristics • Plug-and-play building technology Concept Design Generation The pre-design challenge relates to the central question: “How does one use SET to design and construct a usable demonstration building with superior social and environmental performance that is also economically viable?” It was necessary to remember that building performance had to be the design driver against which every decision would be evaluated. The use of buildings to demonstrate new technologies is not new: case precedent explored included Crystal Palace (1850-1) by Sir Joseph Paxton, Farnsworth House (1945) by Mies van der Rohe, Centre Le Corbusier (1967) by Le Corbusier, and Lumenhaus (2010) by Virginia Tech University. Given the typology of the project building, a pavilion form was adopted. The building is orientated on the east-west axis (see Figure 1), i.e., with the long sides facing north and south and the east and west elevations kept to a minimum to minimise heat gain in the early morning and late afternoon. Fortunately the site supports this orientation as the north facade faces the public street while the south facade faces the internal access road. Off-grid Services The design concept commenced with a roof section for rainwater harvesting purposes: two circumstances were required, 1) that the rainwater should be stored as high as possible so that water could be gravity-fed to the fittings thereby eliminating the need to pump the water from ground level tanks up to a storage tank and, 2) that the rainwater should be collected off a single collector. This suggested a central gutter with a butterfly roof. The butterfly roof also enables the roof slopes to be adjusted to optimise any services thus the north-facing roof (on the south side) could be angled at 34 degrees to optimise solar radiation. The south facing roof (on the north side) could be arranged at a minimum angle to facilitate easy inspection of the biocomposite roof sheets. The roof over the north facade offered the opportunity to design light shelves to project the natural sunlight as deep into the space as possible, thereby reducing the lighting load. The roof overhang on the north side would have to be calculated to exclude summer sun but allow winter sun. Similarly the light shelf could also be used to control direct summer sun. The central gutter, if made wide enough, could serve as a service platform for undertaking monitoring and evaluation of the roof sheets over time, and provide access for regular cleaning of the PVP array. Since only a portion of the central gutter would be needed for access, the remainder could be used for cultivating an extensive roof garden for experimental purposes. This design decision set up the position of the water tanks and the concomitant position of the service cores: as can be seen on Figure 5 the tanks are located immediately under the service roof. Cross ventilation Due to the prevailing and consistent wind at the site, and the need for enhanced ventilation to deal with the humidity, raising the building offered the potential to use displacement ventilation. Taking air in under the building, and exhausting it at the highest point of the ceiling could potentially create a The green building handbook

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stack effect. Due to the prevailing wind direction the exhaust would have to face away from the wind direction so that a negative pressure or suction was created. As is shown in Figure 5 the initial concept was to position the wind chimney on the southern side where the prevailing southerly wind could be used to drive cross-ventilation.

Figure 5: Initial concept in section The exhaust chimneyâ&#x20AC;&#x2122;s also offered an installation position for small-scale wind turbines that could benefit from the acceleration of air over the chimney. Raising the floor on mini-piles or stub columns also would also reduce the impact of construction on the site. The volume under the floor suggested that possibly a rock-bed could be used to cool the air before it entered the building. Plug-and-play construction technology As the building will serve, inter alia, as a R&D test-bed for the development of a range of bio-composite building products and systems including structurally insulated panels (SIPs), it was necessary to free as many of the external walls of any loads so that panels could be removed and replaced. The central gutter and its supporting cores would be used as a skeleton structure off which the rest of the building would be hung thus enabling easy removal of panels without impacting negatively on the structural integrity of the building. The green building handbook

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1st Stage Theory Testing At this stage the section was drawn to scale and a floor plan generated from it (Figure 6) utilising a 300mm metric module to support a typical SIP width dimension (1200mm). The decision to place the rainwater tanks and the service cores directly under the central gutter resulted in an unnecessary and disproportionately high ceiling: it also would have required a mechanical ventilation system for the ablution facilities. The service cores were therefore moved to the external perimeter where the ceiling void created by the butterfly roof could be better utilised to house the rainwater tanks.

Figure 6: Concept drawing A grid of 2400 x 2400mm was generated providing 6 vertical and 3 horizontal bays providing multifunctional spaces in the centre and on both ends. Two stores are located in the central modules to house equipment (including data loggers) which together with vertical bays two and five creates the skeletal structure of the building. These internal core components will be constructed of modular hollow concrete blocks and modular hollow concrete slabs to provide some thermal mass while the external skin will consist of a highly insulated lightweight Alternative Building System (ABT): the theory supporting this arrangement is that the optimum approach to designing a high performance building envelope is to provide a highly insulated skin on the outside to exclude temperature variations on the indoor environment. However, since insulated light structures cannot act as a temperature regulator in the way that a heavy mass material can, the use of thermal mass internally can regulate indoor temperatures through the flywheel effect.

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At this stage a model was built as shown in Figure 7: this model was used to test solar penetration (adjusted for Port Elizabethâ&#x20AC;&#x2122;s latitude) during summer on a two-hourly basis. Simulation was carried out on the design at this stage: first to determine energy consumption to maintain an ideal indoor temperature range, and secondly to model wind flow over the roof using a CFD model. The results of the energy model indicated that energy consumption would be lower than the permissible maximum as stipulated in SANS 204. However, it also showed that further gains could be made if the extensive glazing was either reduced and/or enhanced by using a Low-E glazing assembly. The results of the CFD model indicated that a solar chimney on the northern side would be more effective than a wind chimney on the southern side due to excessive turbulence of the north-facing roof. However, this turbulence identified an opportunity to place horizontal wind turbines in the outer edge of the roof and this will be further explored.

Figure 7: Scale model

2nd Stage Theory Testing The results of the testing were fed back into the design process and the design is currently being further refined. The structural system and off-grid services system can be seen in Figure 8.

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Figure 8: Structural and Services System A second round of simulation will be carried out on the design as it currently stands (Figure 9) to test the efficacy of the refinements with regard to indoor thermal comfort (displacement ventilation) and energy consumption: unfortunately this process was not completed at the time of publication but will be made available in the next edition.

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Conclusion Preliminary findings indicate that it is highly likely that the following objectives will be reached: i) Net-zero energy by reducing internal heat gains and losses, reducing appliance energy demands, and right-sizing the PV array; ii) Net-zero water by reducing demand through providing a closed-loop toilet system and installing low-flow fittings and by harvesting all available rainwater estimated to be about 97 700l, way in excess of what the building requires; iii) Net-zero emissions by reducing dependence on Eskom electricity (GHG emissions) and by installing an off-grid closed-loop toilet system (effluent emissions); iv) Net-zero ecological loss by replacing the displacement of the current low ecological value vegetation with high ecological value indigenous vegetation; and v) Net-zero waste by using a modular-based plug-and-play construction method. These objectives will only be reached because a research method of project scoping, problem definition, solution development, solution testing, and implementation was applied to the design process. Way Forward Final solution testing will now take place, and providing the results are as predicted, system design and technical documentation will commence with a view to starting construction in the second half of 2013. References

DCLG (2010). Code for Sustainable Homes, Department for Communities and Local Government, United Kingdom De Villiers, A., (2011). Comparative analysis of innovative technology and conventional building technology in low income housing, CSIR, Pretoria Duncker L, Wilkinson M, Du toit A, Koen R, Kimmie Z and Dudeni N., (2008). Spot check assessment of rural water and sanitation services for the water sector, 2007/08. DWAF report. Pretoria, South Africa DWAF, ( 2003). Strategic Framework for Water Services. Government Printer, Pretoria Emmitt, S., and Gorse, C., (2005). Barry’s Introduction to the Construction of Building, Blackwell Publishing, Oxford Givoni, B., (1969). Man, Climate and Architecture, Elsevier Glossary of Meteorology, American Meterological Society, http://amsglossary.allenpress.com/glossary, retrieved 2008-05-14. Herz, R., Ed. (1970). Ernst Neufert: Architects’ data, Crosby Lockwood Staples, London. Palmes, J., (1975). Sir Bannister Fletcher’s A History of Architecture, 18th edition, University of London, The Athlone Press, pp.1119-1145. SAIA (undated). Practice Manual, South African Institute of Architects, Johannesburg. UCT (1979). Bioclimatic Chart, School of Architecture, University of Cape Town. Van Wyk, L., (2009). Advanced Construction Technology Platform – Part 1: Developing Innovative Material, Production and Assembly Technologies, CSIR, Pretoria. Worm J., van Hattum T., and de Kat-Reynen, C., (2006). Rainwater harvesting for domestic use, Agromisa, Netherlands. Woudhuysen, J., & Abley, I., (2004), Why is construction so backward? Wiley-Academy, Sussex, England

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Excellence by Design: Boogertman + Partners Boogertman + Partners was established in South Africa in 1982. The company operates from four Regional and two International offices: • Johannesburg • Pretoria • Durban • Cape Town • Nairobi, Kenya • Mauritius

Boogertman + Partner’s projects are conceptually strong, formally expressive and reflect a narrative that engages the site in its physical as well as its socio-economic context. The company is fortunate to have tremendous experience, strength and a skills base that allows Boogertman + Partners to achieve success in a diverse range of commissions. These include: • Apartments, Estates and niche Residential Developments • Bridges & Transportation • Commercial Office Parks • Corporate Offices • Furniture Procurement • Hospitality • Industrial Developments • Furniture Procurement • Interior Design • Medical Facilities / Hospitals • Motor • Refurbishments • Retail • Spaceplanning • Sports, Leisure & Entertainment • Stadia • Student Housing • Urban Design - With strong support from a vibrant and creative Interior Design Department, the company can provide a holistic interpretation to architecture, where the smallest part conveys the truth of the whole. Furthermore, Boogertman + Partners have recently established an Urban Design and Master Planning Department. In recent developments, Boogertman + Partners joined forces with Geyser Hahn Architects to create a unique service in the medical and healthcare industry. Pairing large practice capacity with the smaller, highly specialised skills, it is anticipated that this association will create a unique alliance of expertise and capacity that will offer unrivalled service excellence in the healthcare industry. The International office is focused on the opportunities arising from the 5–10% growth in African economies. Boogertman + Partners currently has on–going projects in Kenya, Botswana and Zambia, with recently completed projects in Egypt and the Sudan, as well as design proposals in Libya, Namibia, Ghana and Uganda. Mauritius has always been a blue–chip investment area, with sustained property values and growth. The first, and possibly only regional shopping centre was commissioned in Bagatelle. The Mall of Mauritius is a 31 415m² retail facility that started on site in October 2009 and was completed in September 2011. As Gold Founding Members of the Green Building Council of South Africa, Boogertman + Partners is committed to supporting the environmentally sustainable transformation of the South African and the International property industry. Boogertman + Partners are excited to be part of South Africa’s First “Green Precinct” at Menlyn Maine, Pretoria. Already having received 4 Star Green Star SA ratings for both Nedbank Falcon Building as well as the recently completed Sage VIP Epsilon Building, Boogertman + Partners are targeting a 5 Star As-Built rating for Nedbank. Menlyn Maine will offer a green lifestyle precinct that will create a responsible living and working environment that not only focuses on energy efficiency but rather the reconciliation of the natural, social and economic environments according to sustainability principles. The desired end-result of ‘green buildings’ is an improved occupant comfort level and health, without being detrimental to the environment. The precinct is the densification of a previous low-density residential suburb with an 56

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Sage VIP Epsilon Buiding - Pretoria

Ernst & Young Head Office - Sandton

Deloitte - Pretoria

Podium at Menlyn - Pretoria

approximate size of ± 140 000m² of commercial office space, 35 000m² of retail and dining spaces, 85 000m² of up-market residential space and 15 000m² of luxury hotel space, all of which will overlook scenic urban parks. The encompassed facilities will allow for commercial and residential residents to easily walk or cycle from one facility to the next within a safe and convenient environment. The urban design is based on the town planning principles of ‘New Urbanism’ to create a vibrant urban character with sound environmental principles. Urban design consideration was given to connectivity, mixed land use, legibility, walkability, robustness, visual appropriateness, biodiversity and security. The character of the precinct’s public domain is defined by the central square, which visually links a series of green urban spaces housing parks, playgrounds and water features. Menlyn Maine is partnering with the Clinton Climate Initiative as one of the chosen 16 worldwide projects with the aim of a ‘climate-positive development’, as well as registered with LEED ND. Menlyn Maine will inevitably add value to Pretoria as a business, leisure and residential destination. The new head office of Ernst & Young, Sandton has been designed in order to achieve a 4 Star Green Star rating, by utilising innovative design opportunities for harnessing natural light and ventilation, energy conservation as well as imbuing appropriate responses to the intricate network of green design considerations. The new head office for Ernst & Young is a uniquely sculpted building that emanates timeless professionalism and creativity, unlocking the potential for an adaptable working environment, resonating itself within a uniquely African environment. Additional projects where Boogertman + Partners have incorporated Green Star Design Principles include: Deloitte - Pretoria, Podium at Menlyn - Pretoria, Walker Creek Office Park - Pretoria, Exxaro Head Office Refurbishment - Pretoria, Steyn City Club House - Johannesburg, The Falls Pick ‘n Pay Johannesburg, Eskom Megawatt Park Refurbishment - Johannesburg, Department of Environmental Affairs - Pretoria. The green building handbook

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BLUESCOPE STEEL

BlueScope Steel Southern Africa markets and sells premium coated steel materials within the SubSaharan African region. The products are sold in coil form to rollformers and roofing system suppliers, who manufacture high quality roofing and cladding systems in various profiles for the market. ZINCALUME® steel, Clean COLORBOND™ steel AZ150 and Clean COLORBOND™ ULTRA steel AZ200 were developed to withstand tough climatic and aggressive environmental conditions which are found in the region. The products have now been sold in South Africa for 15 years and during this period these products have established themselves as a premium product for the roofing / walling segments in South Africa. It is important that professionals, specifiers and homeowners ensure they are using the correct products for the environment in which they are building to ensure maximum performance of their roofing / cladding. As an example, prepainted galvanised products with a Z200 zinc coating mass is not recommended to be used within 5km from the ocean, in fact, no prepainted galvanised product is recommended within 1km from the ocean and from 1 - 5km material should have a minimum coating mass of Z275. The South African market is also being offered zinc/aluminium material with a coating mass of AZ100 compared with the traditional coating mass of AZ150. Prepainted zinc/aluminium steel with an AZ150 coating has twice the lifespan of AZ100 material. BlueScope Steel recommends using only premium metallic coated steel such as ZINCALUME® steel or prepainted Clean COLORBOND™ steel, with an aluminium / zinc coating (AZ150 coating if building within 400m – 5km from the sea). When building within 100 – 400 metres from the water,

The green building handbook

PROFILE

use ZINCALUME® or Clean COLORBOND™ ULTRA steel with an AZ200 coating (coated to a mass of 200g/m² over a steel substrate). This also applies to severe industrial environments – where there are aggressive fumes or particulate fallout within the 400 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 • enhanced chalk resistance properties • resistance to dirt staining • greater gloss retention 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 installation of the roofing / cladding material. Correctly used, our product should give a lifespan up to four times longer compared to conventional galvanised coating Z275 in the same environment. Identification of BlueScope Steel product is easy – each panel of formed roofing material has been uniquely branded on the under surface, thereby avoiding any confusion. Look for the brand.

Contact Details: Wayne Miller, General Manager BlueScope Steel Southern Africa (Pty) Ltd Email: wayne.miller@bluescopesteel.com Tel: 021 442 5420 www.bluescopesteel.co.za The green building handbook

net zero energy

chapter: 2

Defining Net Zero Energy Buildings

Wim Jonker Klunne Senior Researcher CSIR Built Environment Worldwide increasing attention to energy consumption and associated environmental impacts thereof has resulted in a critical attitude towards energy usage of buildings. Increasing costs of energy and dependence on energy service providers add to this as well. The built environment in general, and buildings in particular, are responsible for a considerable portion of energy consumed and would therefore be a prime attention area for energy efficiency interventions. The building sector can significantly reduce energy use by incorporating energyefficient strategies into the design, construction, and operation of new buildings and undertaking retrofits to improve the efficiency of existing buildings. It can further reduce dependence on fossil fuel derived energy by increasing use of on-site and off-site renewable energy sources.

Image credit: www.ge.com

The green building handbook

net zero energy

chapter: 2

Net Zero Buildings

The concept of a Net Zero Buildings is getting more and more attention and is currently being implemented in some form or the other in South Africa and other countries worldwide. Currently a limited number of building could qualify as Net Zero Buildings, but developments in energy saving and renewable energy technologies, building materials and construction techniques are advancing rapidly, enabling Net Zero to become a mainstream requirement for new developments. As with any evolving field of attention, several definitions exist for Net Zero Buildings. However, it is commonly understood that a Net Zero Building combines a design to minimise energy requirements with the generation of energy by means of renewable energy technologies. The NREL publication “Zero Energy Buildings: A Critical Look at the Definition” explores definitions in detail, and it suggests four ways in which net zero energy may be defined: • Net Zero Site Energy: A site Zero Energy Building produces at least as much energy as it uses in a year, when accounted for at the site. • Net Zero Source Energy: A source Zero Energy Building produces at least as much energy as it uses in year, when accounted for at the source. Source energy refers to the primary energy used to generate and deliver the energy to the site. To calculate a building’s total source energy, imported and exported energy is multiplied by the appropriate site-to-source conversion multipliers. • Net Zero Energy Costs: In a cost Zero Energy Building, the amount of money the utility pays the building owner for the energy the building exports to the grid is at least equal to the amount the owner pays the utility for the energy services and energy used over the year. • Net Zero Energy Emissions: A net-zero emissions building produces at least as much emissionsfree renewable energy as it uses from emissions-producing energy sources. In general, when using the terminology “Net Zero Energy Building”, we are referring to a building for which the annual amount of energy used in its operations is equal to the amount of energy generated by the building. If the amount of energy produced by the building is exceeding the amount of energy used, we are talking about Net Energy Plus Buildings.

How to reach Net Zero Energy?

Net Zero Energy can be reached in three easy steps: 1) Sustainable design 2) Reduce energy consumption 3) Renewable energy generation

Sustainable design

For a sustainable design of a building we will have to look at passive solar design foremost. Orientation of the building, fenestration and daylighting, ventilation, insulation and materials use as well as heat and cold sinks are the most important elements to look into.

Reduce energy consumption

A very critical look at the energy consumption in the building is required, with a specific emphasis on the use of energy efficient lighting, high energy efficient appliances, water saving shower heads, motion detectors, etc.

Renewable energy generation

The most obvious form of renewable energy generation for buildings is using the roof (and façade) for solar PhotoVoltaic (PV) electricity generation and solar thermal energy generation for hot water, but also wind energy could be considered. If the location of the building allows, on-site energy generation with biogas or small hydropower are options as well. Alternatively the energy use at the building site The green building handbook

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net zero energy

can be offset by renewable energy generation at a different location, either on a kWh per kWh basis or on a carbon emissions basis.

The role of the electricity grid

Net Zero Energy Buildings generate the same amount of energy as they consume on a yearly basis and use electricity grid as a balancing medium. In periods of high energy production and low energy consumption (for office buildings with solar PV typically during daylight over the weekends, when the energy demand is typically very low) the electricity that is not used by the building itself will be fed into the electricity grid. Similarly, during periods of higher electricity consumption than production, electricity will be drawn from the grid. On an annual basis the balance between supplying electricity to the grid and drawing from it will be zero. For Net Energy Plus Buildings this balance will be positive, i.e. more energy is produced by the building than consumed. A pre requisite for this is the availability of an electricity grid that can be used as â&#x20AC;&#x153;batteryâ&#x20AC;? for the building. This grid must be able to accommodate the produced electricity technically and legally. The current situation in South Africa is such that, although the grid is technically able to receive electricity, no legal framework exists to accommodate this. Currently a limited number of pilot projects are ongoing in Cape Town to investigate what is needed to change this situation. Alternatively, any energy surplus or shortfall can be accommodated on the user side of an electricity connection in cases where the Net Zero Energy building forms part of a larger complex, like for example an office block linked to an industrial plant. 64

The green building handbook

net zero energy

chapter: 2

Image credit: www.archdaily.com

Advantages and disadvantages

Net zero energy buildings do have certain advantages and shortcomings which will be discussed here briefly.

Advantages • • • • • • •

The building (owner) is not exposed to future energy price increases Reduced total cost of ownership due to improved energy efficiency Reduced total net monthly cost of living / occupation Improved reliability – the building can operate during black outs Extra cost is minimized for new construction compared to an afterthought retrofit Higher resale value of the building Future legislative restrictions, and carbon emission taxes/penalties may force expensive retrofits to inefficient buildings

Disadvantages

• Initial costs can be high • Few designers or builders have the necessary skills or experience to design / build Net Zero Energy Buildings • Challenge to recover higher initial costs on resale • Grid connection is still required to balance the energy demand and supply – this could become a problem if large numbers of Net Zero Energy Buildings are connected to the grid • Risk of future shading on solar system, hence reduction in generation • Tendency to compensate high heating and cooling requirements by larger renewable energy systems rather than reducing the energy requirements The green building handbook

net zero energy

chapter: 2

Conclusion

Although no uniform definition of Net Zero Energy Buildings does exist, it is typically understood that these are grid connected buildings that consume the same of amount of energy annually as is generated on site. Due to legal and technical reasons feeding electricity into the electricity grid is not (yet) allowed in South Africa, which hampers the uptake of Net Zero Energy Building principles.

The green building handbook

PROFILE

African Water Controls cc

African Water Controls is the authorised distributor of Neoperl’s range of pressure-compensated regulating valves. Neoperl is a German company and world leader when it comes to pressurecompensated regulators. These regulators allow us to manipulate the flow of water in any outlet or inline. We can therefore accurately predict water usage and from this calculate the money saved in terms of water and energy consumption. Pressure-compensated regulators, unlike their restrictor cousins, are a sophisticated technology that can compensate for varying pressures (with the use of a non-hydroscopic control ring), while always allowing the prescribed quantity of water to flow, and they help to balance the pressure in the rest of the water network. The applications of this product can vary from a domestic shower environment to a multi-storey hotel that has to employ expensive mechanisms to ensure that the higher storeys have sufficient water. Because we can accurately predict the quantity of water required in a given room, quantity surveyors can accurately calculate the correct sizes of geysers, pumps, piping, which in turns reduces costs. Another in demand range of products are our vandal resistant showers. We have been in this industry for nearly 30 years and have the 50 years experience of Neoperl’s scientists to rely on, should your situation require it.

Contact details:

African Water Controls cc Tel: +27 11 331 9425 • Fax: +27 86 770 5345 Email: contact@africanwater.co.za Web: http://www.africanwater.co.za 68

The green building handbook

PROFILE

NEOPERL is the German maker of the internationally renowned and industry-leading Pressure Compensating Aerators (PCA) and Constant Flow Regulators (CFR). Quite simply, these devices have been proven to achieve anywhere from between 40% and 60% savings in water consumption – which translates to between 40% and 60% savings in your residential or commercial water bill, while protecting your faucet’s original manufacturer’s warranty. Furthermore, in some developed countries such as Singapore and Australia, products are required by law to be labelled according to their water efficiency. This programme is known as the Water Efficiency Labelling and Standards (WELS) Scheme, and by installing a PCA or CFR, any product can be turned into a top-rated WELS product. But most importantly, while other water-saving devices result in noticeably weaker water pressure, NEOPERL’s high-precision mechanism ensures a constant and fixed flow rate, which means an unnoticeable difference in terms of water pressure, in both residential and commercial applications.

Italy:

In 1995, Italy introduced a new energy-saving directive aimed at the reduction in CO2 emissions as specified in the Kyoto treaty. Italy was the first country to introduce white certificates as a marketing instrument. By creating an “artificial market”, energy suppliers were committed to put in place energysaving measures for the benefit of consumers. The green building handbook

PROFILE

â&#x20AC;&#x153;Free NEOPERL water savers for Italian householdsâ&#x20AC;? -One of the energy-saving measures used by several Italian energy suppliers was to provide NEOPERL water savers to their customers free of charge. In 2006 and 2007, a total of 7.5-million NEOPERL water savers were distributed throughout the country. The energy suppliers were then able to fulfil the commitments set out by the new directive. Reducing water consumption means that the energy required to process water is saved and that CO2 emissions are reduced. The consumer saves money and makes a contribution towards the environment and climate protection.

South Africa:

In 2012 Eskom initiated a rollout programme that supplied their consumers with free solutions for saving energy, of which energy-efficient shower heads where included. We supplied tens of thousands of our showerheads with Neoperl regulators to the market, and in addition to that hundreds of thousands of regulators to other suppliers so they could turn their showers into pressure-compensated showers. Although we cannot claim that all showers rolled out had our Neoperl technology, we do believe that those clients who did receive a shower with our technology included will benefit from a long-lasting, superior shower and predictable savings.

United Kingdom:

In 2011 with the help of the utilities Neoperl supplied water and energy saving devices to 4 million households. To date any household in the UK can request regulators from their utility company. 70

The green building handbook

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

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Transport & Mobility South Africa Volume 1

The Essential Guide

The

Water Resource

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Sustainable Handbook

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

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The Guide to Sustainable Waste Management

South Africa Volume 1

Renewable Energy The Essential Guide

PROFILE

Eco-friendly roofing from Metrotile Metrotile SA focuses on bringing a range of unique and ecofriendly roofing products to the SA market. Successful all over Europe and in many African countries, Metrotile (Europe) has put their weight behind Metrotile SA to replicate their international success. The innovative European manufacturer provides affordable, lightweight stone-coated roof systems in highly protective AZ185/Z300 corrosion-resistant steel, ideal also for coastal applications. This premium steel roofing system goes beyond the performance of traditional roofing materials, while convincingly maintaining the look of the traditional roof tile. This premium roof system is ideal for use on new projects and re-roofs, specifically for thatch and old “zink” roofs, creating an effective weather barrier, removing the high maintenance requirements and shielding the property from fire and hail. This can also save owners of thatched properties around 30% on their insurance premiums. Because they are far lighter than traditional roofing, they don’t require the same heavy (and expensive) roof structure and being recyclable they are in tune with current sustainability trends. Metrotile is conscious of the environment and with an average lifespan of more than 30 years this sustainable roofing system requires little maintenance and is 100% recyclable. The carbon footprint left is also smaller because they weigh on average only 6kg/sqm, and much less transport is needed than for traditional roofing of the same coverage. Further contributing to a green future, Metrotile leads the way in energy-saving roofing with its Metrotile Lightpower photovoltaic solar tile and proprietary ventilation systems. “Lightpower” generates 60Wp per tile and because it is integrated into the roof tile, it is more secure than retrofitted solar panels and does not spoil the aesthetics of the roof. The energy efficient ventilation systems add to the heat reflective steel substrate for a cooler roof, in line with the regulatory move towards more energy efficient buildings in South Africa. The PV system is ideal for new roofs and re-roofing and integrates with a number of the popular Metrotile profiles eg. Metrotile Woodshake/Thatch, Metrotile Bond and Metrotile Roman. In their quest for the constant improvement of the “Metrotile experience”, Metrotile SA is actively recruiting and training teams of competent installers to ensure that their roof installations match the quality and reputation of their premium product. And to underpin their commitment to proper installations, they are also offer a free maintenance plan for all new Metrotile roofs, installed by their approved contractors. These initiatives are some of the reasons why the name “Metrotile” is equal to “peace of mind” and fast becoming the preferred supplier of eco-friendly roofing systems in the world. Contact Stephan Schoombie: CE+27 82 4518711, Fax: +27 86 6483231 or info@metrotile.co.za for more information.

The green building handbook

PROFILE

The green building handbook

Net Zero Water

chapter: 3

Mauritz Lindeque Hydraulic Infrastructure and Engineering Built Environment CSIR Is it possible to develop a building that uses a net zero amount of water? In recent years it has become evident that it is possible to have buildings that use a net zero amount of electricity. This is possible when the building is taken off the national grid. The need to do this, especially in South Africa, is because up to 93% of our electricity is generated from coal fired power stations. The impact that the emission of carbon dioxide (CO2) has on the environment and global climate change has led us to develop renewable energy (RE) systems that can generate electrical and thermal energy by using energy from the sun. This includes technologies such as photo voltaic (PV) panels for the generation of electrical energy, solar water heaters (SWH) for the generation of thermal energy, and also concentrated solar systems that is used to concentrate the solar energy in trough collectors or to a solar tower where the intense energy is used to turn water to steam that then turns turbines for the generation of electrical energy. The only limiting factor at this time may be the capital expense on a domestic scale that makes it economically unattractive. Presently only small scale systems are installed to generate electrical energy for lighting as it is too expensive to operate other appliances from electrical energy generated from PV systems. The unfortunate situation with water is that there is no replacement technology for water. Water can be supplied from many different sources. One needs to take in to consideration however, where the water originates from. This increasing demand from the growing world population, of 7 billion people is placing strain on the environment. This is causing irreparable damage. It is not only humans that need water. It is also the environment that sustains life that requires water. The more people we need to feed the more ground water we require. This is water that is used for agriculture as well as daily use in residential applications. Examples where the harvesting of groundwater has left lasting damage is in areas where ancient subterranean water supplies are being depleted includes the Nubian Sandstone Aquifer (Waltina & Neubrt 2009). Figure 1 below points out some of the larger aquifers across the globe that spans many international borders.

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Net Zero Water

Figure 1: Examples on the globe where large trans-border aquifers occur.

Figure 2: The Nubian Sandstone Aquifer (NSAS) crosses over the borders of 4 countries. Figure 2 above points to the area that is covered by the NSAS. This is an area that falls in a present day desert area surrounded by the Sahara desert. Six thousand years ago this area received higher rainfall and allowed for the aquifer to be replenished by regular precipitation (Eltahir research group 2003). The rapid desertification of the area within one generation and the decrease in rainfall resulted in less to no replenishment of the aquifer. The increase in population and use of technology to gain access to the aquifer in modern times has resulted in a depletion of the ancient water supply. 76

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Net Zero Water

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In some cases there are countries with greater budgets and therefore greater access to technology that allows them to harvest water from these sources. The damage to the environment in neighbouring countries can lead to loss of arable land and pasture and potential conflict. There are no international agreements or treaties in existence to deal with water sources that cross international boundaries that address the harvesting and utilisation of a resource on international set agreements and understandings (Mostert 2010). South Africa is also classed as a water scarce country. We have an increasing population and growing economy that places a higher demand on our water resources. The development of the Katse dam in Lesotho is an example where water is imported to sustain the industrial complex of Gauteng that in turn fuels the South African economy. The generation of electrical energy from coal fired power stations consumes large volumes of water. This water is used for the cooling of the steam system that is used to turn the turbines that generate electrical energy. It is estimated that the water that is used in a coal fired power station can be as high as 95 litres to produce 1 kilowatt-hour of electricity (W.D. Jones 2009) Water is also used in other processes that allow us to generate the different forms of energy that we have become accustomed to in our modern life styles. Water is in some cases used to extract crude oil out of the ground. This is achieved by introducing the water to the oil wells. The fact that oil and water have different specific gravity values means that the oil will float on top of the water thereby causing the oil to rise in the wells when water is introduced. Water is also used in the removal of pollutants in the exhausts over power plants. There are losses in the generation of the steam that drive the actual turbines and it is also used to flush away the residues that are deposited from burning fossil fuels. What this means is that a net zero energy development will move closer to a net zero water development by reducing the demand on electrical energy that is generated from coal fired power stations. However the remote and centralised energy generation for the national grid is not the only consumer of water. The building and occupants also consume and pollute water on site. What is a net zero water building then? The Green Building Council of Cascadia in Seattle describes a net zero water building as a building that does not exceed that water budget of the site on an annual basis (Cascadia Green Building Council 2011). The South African Green Building Council potable water and sewerage calculator for the multi-unit residential rating tool uses the water efficiencies of fittings (such as WCs, baths, kitchen and basin taps, and showers). This, in conjunction with the reduction in the use of potable water through rain water harvesting projects and the recycling of grey and black water, is used in the calculator under Wat – 1 (Occupant amenity water) and Emi – 6 ( discharge to sewer) credits respectively (Green Star SA – Multi Unit Residential V1 Water Calculator Guide Version 1). There are certain areas within and around a building where it is advisable that the occupant is exposed to pathogen-free water. This would be uses where there is a possibility that the occupant of the facility stand’s a good chance to ingest the water. Then there are uses where the water quality is of no concern as the occupant should not come into direct contact with the water. These different uses can then be supplied with water that originates from different sources. Understanding and planning for the areas that require clean water will allow the designer to design systems that will reduce the demand for this clean water. If the building is in the design phase then it will allow the designers to allow for alternative reticulation systems that will transport the clean or recycled water through the building. The Green Building Council of South Africa quotes the Australian Department of the Environment by stating that a typical office building of 10 000m2 typically consumes over 20 000 litres of water per day. This can amount to 7 million litres per year. The green star South Africa Rating tools aims to encourage a reduction in the use of potable water. This will result in reduced pressure on our water supply. The green building handbook

Net Zero Water

chapter: 3

Aspects that are taken in to consideration include: • • • • •

Where the predicted water use through sanitation is reduced Where water metering is used for monitoring and control of water use in the building Where recycled water replaces potable water for landscape irrigation Where cooling systems use heat rejection systems other than water Where the use of potable water for fire protection and essential water storage is minimised

These points are scrutinised when a building is submitted for the green star rating. It will also be more cost effective and productive if it is incorporated into the building at the design phase. This will allow the designer to incorporate the different reticulation systems and the storage that will be required for the different sources of water. If a building has to be retrofitted with such systems it could be more cost intensive as the building was not designed to accommodate such systems (GBCSA 2011). Not only are the use of water and the reduction of potable water use taken into consideration but also the effluent from the building. This will reduce the pollutants that enters natural water courses or also the pollutants that put the Municipal Waste Water Treatment Plants under strain. There are different sources that water is traditionally supplied from: • • • • • •

Municipal water Traditional methods would require a qualified plumber to connect the new development to the municipal water supply. Some of the benefits from this supply in South Africa are that: The water is under pressure (Min flow rate = 10 litres/min) which means that little to no intervention is needed to supply water to double story residential structures (Department of Water Affairs 1997) The water is treated and therefore fit for human consumption The supply is reliable as a utility company is responsible for the supply and maintenance Requires no further storage on site Requires no complicated reticulation systems However, using municipal water does not mean that the building or development is a net zero water development as discussed.

•

Borehole water.

In many areas water that is supplied from boreholes could be tested and used for human consumption. The impact that large scale tapping of the aquifer will have on the environment could however lead to permanent damage. The practical aspects of the bore hole water is 1) Drilling for the water. This is practical where the drilling rig can have access to an area. In cases where the actual borehole is far from the end users then it requires a reticulation system and pumps. The first pump will be to raise that water from the well. This could exceed 130 meters in some cases. The larger the pump that is required becomes the harder the pump needs to work. In cases where the hole is very deep and the water needs to be transferred over a large distance then a three phase (380 Volt) system is required. Conventional domestic houses are only equipped with single phase (240 Volt) system. From the borehole that water must be supplied to a header tank. This is a storage tank that allows for a buffer supply of water. If the tank is on an elevated stand, then gravity will suffice to supply the water under reasonable pressure to the building. Alternatively when there is no option to store the water in an elevated header tank then a pressure pump will be required. Figure 3 below depicts a basic layout of a water supply system connected to a bore hole. The green building handbook

chapter: 3

Net Zero Water

Figure 3: Water reticulation from borehole water A Pressure pump is an electrical pump that is activated when a pressure sensor detects a pressure drop in the system. This pressure drop is achieved by opening a faucet or by flushing a toilet. The release of water from the system at that point along with the surface tension of the water then draws water from the pipes. This reduction in pressure or “loss of water” will then activate the pump that will increase the water pressure in the system as long as there is a supply of water in the buffer tank. The borehole however does require electrical energy to operate and also takes water from natural sources that sustain life. •

Rivers and streams

When water is to be harvested from rivers and streams it is difficult to know what pollutants are introduced to the water system upstream. The supply can also be unreliable due to the seasonality of many rivers and water causes. The water supply from rivers is very dependent on the upstream influence from residents on the river banks in the form of pollution and supply. Before the water from rivers or stream is used for human consumption it will require treatment. •

Dams

The construction of dams for the purpose of water supply can be very costly in capital expenditure but also in operational expenditure. If the dam is constructed in an area with little ground cover that will protect the topsoil during high rain fall periods then it will result in the dam silting up. Dams also offer large surface areas of water to solar irradiation that result in evaporation. The evaporation of the water will then result in a net loss of water. •

Rain water

The harvesting of rainwater has been used by humans for many years and has become more popular as of late due to the increasing drive to limit the impact on the environment. The scale of development that is happening in South Africa with housing communities and gated communities has decreased 80

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exposed top soil that can absorb natural precipitation. Surface areas such as roofs, paved roads and public areas offer perfect areas where rain water can be collected and harvested. The water harvested from such systems may contain pollutants and should also not be used for human consumption if harvested in an urban area. Some of the pollutants that may be found in urban areas include gasses that are associated with the burning of fossil fuel in an internal combustion engine. As mentioned water is used for the filtration of exhaust gasses from industry as water, including rain water, is very efficient in absorbing gasses. These gasses may include Nitrogen oxides (NOx) and Sulphur oxides (SOx). Other pollutants may also include: • Mosses • Lichens • Windblown dust • Urban pollutants • Pesticides • Insecticides There are many other uses for this water as discussed. If water borne sanitation is used then this water can be used for toilet flushing or alternative such as irrigation cooling and general cleaning of the facility. Harvesting of rain water from a roof will require that the water is stored. The stored water will then require energy to transport it to areas where required. When the water is harvested from a roof area the water is lead into storage tanks. When a reticulation system is designed to transport the water to the point of use then it will assist in the reduction of the energy requirements if the endpoint is downhill from the storage. Alternatively a pump system must be installed that can place the water under pressure that will transport it to higher ground where it may be required. The addition of the pump may be a step away from net zero energy unless the electrical energy required by the pump is generated from RE systems. Calculating the size of the storage system will require data inputs into a basic calculation. This data include the annual rainfall for the area. It will be more accurate if the data is gathered from a source that can supply accurate measurements that spans a number of years. The average annual rainfall can then be used. The roof surface must be taken in to consideration. The resistance that the roof surface will present to the water when it runs down to the guttering will be seen as a coefficient. The industry standards state: • Metal roof in the form of corrugated iron = 0.7 – 0.9 • Tile roofs = 0.8 – 0.9 • Concrete roof = 0.6 – 0.8 The surface area of the roof will then be calculated using the examples below. It is not the total roof surface that is measure but the footprint that the roof presents to the sky. It can be seen that the actual footprint seen from above will be less that the surface area covered by the roofing material. Figure 4 A, B, and C represent the surface areas for different types of roofs. As can be noticed in Figure 4 B and Figure 4C the actual surface of the roofing material is very different but the catchment area is the same. Figure 4 D is a more simplified explanation of the surface that is presented to the rain. The equation for calculating the potential volume of water that can be harvested is as follows (UNEP).

The green building handbook

Net Zero Water

chapter: 3

Liters/year = Rainfall (mm/year) x Area (m2) x Runoff coefficient

Figure 4 A:

Figure 4 B:

Figure 4 C The green building handbook

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Net Zero Water

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Figure 4D: A more simplified explanation of the surface area calculation Alternatives to using the roof structures of buildings may be making use of the natural environment. Figure 5 below is an example where a natural rocky outcrop or â&#x20AC;&#x153;kopjeâ&#x20AC;? in the Serengeti was used to harvest rain water. When harvesting rain water it needs to be remembered that some organic and inorganic solids will be harvested with the water. The physical and mechanical action of the rain falling on the surface will result in the rain flushing these solids into reservoirs. There are systems available commercially that allows for a simple filtration method of such solids. These systems however will not suffice in filtering out dissolved pollutants and materials. The natural rocky outcrop seen in figure 5 is set in a wildlife area. This means that animals have free access to the catchment area. Similarly in urban areas there are always birdlife and rodents that may use the catchment areas. Seasonal leaf litter and other vegetation may also end up in the catchment systems. The green building handbook

ANDREW NIMMO ARCHITECT

www.nimmo.co.zo

Net Zero Water

chapter: 3

Figure 5A: Using the natural environment to harvest rain water This camp is in a part of the South Western Serengeti where there is very little water available for domestic use. This system allows this facility three months of autonomy.

Figure 5B: The reservoirs constructed to store 1 million litres of rain water The green building handbook

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Net Zero Water

chapter: 3

Ideally when a roof is used for rain water harvesting then it will require filtration systems to prevent solids from blocking the reticulation system and also from polluting the water supply. Gutter mesh will assist in decreasing the amount of solids that will collect in the guttering. With the organic matter such as leaves being deposited on the mesh it will prevent a build-up of leaves that will then remain moist and decompose. The aeration of the leaves on top of the mesh will allow for the matter to air dry and be removed by slight breeze. If some solid matter does happen to bypass the mesh, a first-flush system is required. This is also available commercially. The principle of a first-flush system is to install mechanical filters in the form of wire mesh and nylon filters that are connected to a sump. The water that is collected from the roof will firstly collect in a sump that will accommodate a measured amount of the rain water as seen in figure 6. This first flush will also allow for the accumulation of the solid material in the sump. Once the sump is filled, the overflow will fill a storage tank.

Figure 6: Representation of a first flush system installed onto a domestic roof This system is not maintenance free and requires that the build-up of organic material in the first flush system is cleaned on a regular basis. The water from the storage tank will require a pump to circulate it to areas where it is required if the storage tank is situated on ground level. Biological Treatment The treatment of water through a biological process is a natural method where naturally occurring bacteria is employed. This is a complex biological process that is employed by municipal waste water treatment plant (MWWTP). This process can be used for the treatment of black water with great success. A very basic explanation of how the system works can be seen in figure 5. Although this is an explanation of the workings of a MWWTP it can become clear through explanation the two different streams that are followed. One stream is for the treatment of the waste water and the other stream is for the treatment and stabilisation of the solids. The treatment of the solids can have a benefit where a renewable fuel source in the form of a methane (CH4) rich gas is produced (Ross et al., 2009). This occurs in the anaerobic digester or AD as pointed out in figure 6. The green building handbook

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Figure 6: Typical layout and operation of a waste water treatment plant. The anaerobic digester is circled and named AD Figure 6: Typical layout and operation of a waste water treatment plant. The anaerobic digester is circled and named AD The waste water arrives at the MWWTP in a mixed solid and liquid stream. The goal of the presedimentation point is to allow for the solids to settle in the separators. This allows for the withdrawal of the solids from the bottom of the separators and the water from the top of the separators. The water is diverted to a stream where air containing atmospheric oxygen is introduced. This allows aerobic bacteria to treat the water through chemical processes that changes the composition of some of the pollutants such as ammonia (NH3) and phosphorous (P4). The solids that are removed from the water are introduced into the anaerobic digesters in sludge form with a solid content of 4-5%. The anaerobic digestion process occurs only in an environment that is void of atmospheric air. This means that the vessel where the anaerobic bacteria prefer to live needs to be airtight. Figure 7 below is an example of a WWTP that has been in operation for more than 100 years. The Dasspoort municipal waste water treatment plant makes use of modern aerobic treatment processes where oxygen is introduced to the waste water through aerators. There are also biological filters that were used with some success in the past. This is where a fixed film of bacteria is allowed to grow on the surface of a medium. The medium in this case is small gravel stones. The tiny facets on the stones allow for the bacteria to grab a hold and multiply. Between the gravel pieces there are cavityâ&#x20AC;&#x2122;s that then causes the water to â&#x20AC;&#x153;cascadeâ&#x20AC;? over the medium. This cascading action allows for the water to be oxygenated. Figure 7: Dasspoort municipal waste water treatment plant in Pretoria (Below) The circles at the bottom right of figure 7 are the older biological filters that are still in use today. The top left of figure 6 represents the newer activated sludge part of the MWWTP. For smaller scale waste water treatment facilities there are modern technologies that supplies plastic or injection moulded medium that will allow the bacterial film to grow. Figure 8 below is an example of such a system and Figure 9 is a representation of the modern filter mediums compared to the more traditional gravel filter medium. Systems that employ such a biological process can be employed to treat grey of separated black waste water. 90

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Figure 7: Dasspoort municipal waste water treatment plant in Pretoria

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Figure 9: The more modern filtration mediums compared to more traditional gravel stones

The basic principles of such biological process also occur in nature and can be found on natural reed beds and other wetlands. In a reed bed or wetland system it is not the plants that treat the water but the environment that is created around the roots. The roots provide a surface for the natural bacteria to grow and also a medium for filtration. Other benefits of using natural reed beds where possible is that the stems and reed plants act as shade that blocks sunlight from penetrating the water. With the high concentration of nutrients in the waste water it is an ideal environment for algae to grow. Algae however require sunlight for photosynthesis and this is prevented by the shade. The over population of algae in an aquatic environment rids the water of oxygen and then would not allow for natural processes to break down the pollutants. This oxygen is important as it is required in the transfer of gasses from the air to the water through the submerged parts of the plants. The construction of a wetland also serves to improve the environment of an area through aesthetics as well as providing a space for animals and birds to find refuge. Figure 9 is a good example of such a wetland system.

Figure 10: A constructed wetland for the treatment of waste water

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The water from these systems should not be used for human consumption unless sufficient sterilisation and complete analysis to establish the level of pathogen removal is completed on a regular basis. Biological processes are not well known for the removal of heavy metals. This however should not be a problem with a domestic system as the heavy metals typically originate from industrial waste. With systems such a biological filters it is still required that the water is disinfected. This can be done by using chemicals such as chlorine. A chlorine treatment process is added to the stream at the end of the treatment facility just before the water is reintroduced to the environment or where the water is return to a header tank or water supply. One area of a building that requires the most water is the toilet systems. Every time a person uses a toilet there is up to 13 litres of water that is used. This is a result of the water coming into contact with the pollutants associated with flush toilets. Once the water comes into contact with solid waste in the toilet it is contaminated and requires treatment before disposal. In urban areas water borne sanitation will have an end point in the municipal waste water treatment plant where the solids and liquids are treated as mentioned before. It is therefore suggested that if the owner or occupant of the building insists on water borne sanitation a system can be designed where recycled water is used in the flushing of the toilets. This will reduce the demand for clean potable water to be used for sanitation. The alternative to water borne sanitation will be compost toilets. A compost toilet is a system that allows for the dewatering of the solid waste. In many areas pit latrines are used for this task but more modern manufactured systems have been designed to allow for an installed system that can be used indoors. Additional to a conventional compost toilet is a urine diversion (UD) toilet. This is a system as depicted in figure 11 that separated the urine/liquids from the solids. When the urine separation is achieved it reduces the odours associated with pit toilets by reducing the volume of ammonia (NH3) that mixes with the solids. This then results in a system that is more conducive to indoor use. With a UD toilet the urine will be captured in a separate receptacle. This can be diluted with water and used as a liquid fertiliser. The solid matter reduces in net volume as the solids are dewatered. The lack of odour and the fact that the solids are exposed to air results in a solid material that can be used as a fertiliser in gardens. Although the cleaning process of the toilet will require some water, it will still be less than a typical 13 litre flush of water. Many waterless urinals are also available commercially that allow for odourless operation

Figure 11: Urine diversion (UD) toilet

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Alternative methods for the disinfection of the water can also be thermal treatment. This is where the water is boiled or heated above 80°C to allow for Pathogen destruction. This is a very energy intensive process though and will move away from a net zero energy building. Reverse osmosis (RO) or as it is known as desalination is another method of treating water. This is a process where the water is passed through a series of filters such as • sand for the removal of large suspended particles • Activated charcoal filter for the removal of odours and taste from the water • And 5 micron filters to remove smaller suspended particles The last stage of the RO process is for the water to be pressurised to ± 20 Bar and forced through membranes that removes microscopic pollutants from the water. RO is also a very energy intensive process and requires electrical energy to achieve the pressures required for the treatment of the water. Conclusion It may be possible to design a building that incorporate net zero water design principles. This is if the net zero water principles are purely to reduce the predicted use of potable water in the building. There are many mature and proven systems and technologies that can reduce the use of potable water dramatically. These systems can be incorporated in a building and reduce impacts that reach beyond the walls or boundary of the building. Harvesting and use of rain water will reduce the influx of water into the sewer system and therefore reduce the demand for capacity on the municipal waste water treatment plants. Every drop of water that enters the sewer comes into contact with contaminants and requires treatment. These plants require electrical energy to treat water. Lessening that demand for electrical energy will lessen the demand for more water to generate the electrical energy. Therefore there is a water cycle that has to be considered holistically. References Climate change 600 years ago in the Sahara desert explained. MIT News Monday March 31 2003. Read 2 Dec 2012 Available on the web at: http://eltahir.mit.edu/news/climate-change-6000-yearsago-sahara-desert-explained Conflict and co-operation in international freshwater management: A global review. Erik Mostert, Delft University of Technology. International Journal of River Basin Management. Read 29 Nov 2012 Available on the net http://www.tandfonline.com/loi/trbm20 Department of Water Affairs and Forestry. Regulations under section 9 of the water service act (Act No. 108 of 1997) Norms & Standards for Quality Water Services. Explanatory notes and guidelines available on the web http://www.dwaf.gov.za/dir_ws/waterpolicy/vdFileLoad/file.asp?ID=586 Guidance for innovative water projects in Seattle (February 2011) Available on the net http://livingfuture.org.cascadia/ideas-action/research/water/regulatory-pathways-net -zero-water Green Star SA – Multi Unit Residential V1 Water Calculator Guide Version 1. Available on the net at http://www.gbcsa.org.za/docs/greenstar/GSSA_MUR_v1_Water_Sewage_Guide_20111027.pdf GBCSA Green Building Council of South Africa Technical Manual Green star SA Office v1 Ross, W.R., Novella, P.H., Pitt, A.J., Lund. P., Thomson. B.A., and Fawcett. K.S. (1992). Anaerobic digestion of waste water sludge: Operating guide. Water Research Commission of South Africa. Project no No. 390, published TT55/92 Pretoria South Africa. Waltina & Neubrt Transboundery water management in Africa: Challenges for development cooperation. German Development Institute ISBN 3-88985-326-9 ISSN 1860-0468 URI: http://hdl. handle.net/123456789/26068 W.D. Jones, 2008. How much water does it take to make electricity? IEEE Spectrum journal. Institute of Electrical and Electronics Engineers. Read 4 Dec 2012. Available on the web at. http://spectrum.ieee. org/energy/environment/how-much-water-does-it-take-to-make-electricity 94

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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

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 purposes of sale, repair and/or extensions to maximise use of land and return on Investment.

Project Management

The Group offers the above service as detailed hereunder: 96

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PROFILE 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.

Development Planning

• Project Identification • Feasibility Studies • Project Conceptualisation • Project Capital Procurement • Public Involvement Co-ordination Programme

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

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.

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PROFILE

CEMENT & CONCRETE INSTITUTE The Cement & Concrete Institute (C&CI) grows the demand for concrete in all its forms, both in absolute terms and relative to competing materials. To achieve this, the C&CI provides information, advice, innovative technical consulting and training solutions to the construction industry. The Institute’s members cover a broad spectrum of stakeholders in the concrete industry and fall within three categories – Producers, Associates and Built Environmental Professionals. The all-inclusive nature of this structure helps to ensure that C&CI’s activities are focused on the areas of the greatest need and potential. In this way, the competitive position of concrete in the building materials market is continuously strengthened. The C&CI’s multi-disciplinary technical team of architects, engineers and concrete technologists tracks international trends and implements projects that both solve existing challenges (specific to South Africa), and promote future growth particularly in the area of sustainability, quality and industry capacitation. The team focuses their attention on the following critical areas to influence growth in the short and long term: Sustainability, Standards and Specifications, International Trends and Quality.

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These are the services offered by C&CI

• Comprehensive information on cement and concrete The Information Centre houses a unique and comprehensive collection of books, journals and technical reports on all aspects of cement and concrete. This library contains an extensive collection of more than 100 000 items on cement and concrete and also operates a unique database, allowing user-friendly, electronic searching of information through the C&CI website. The Institute issues a range of publications covering a wide variety of cement and concrete related topics. There are over 40 titles currently in print. • Education in concrete technology and practice. The CETA-accredited School of Concrete Technology offers training countrywide and has a portfolio of courses ensuring that the quality of concrete produced is of the highest standard. • Specialist technical services. The Institute has an established reputation for providing high quality, independent, professional services to private and public sector clients. C&CI’s consulting service is focused on concrete and related issues and takes the form of advice, verification or investigation. The Institute’s engineers and architects are available for consultation by telephone, e-mail, at our offices, or if preferred, on the relevant construction site anywhere in South Africa. It also offers general technical advice through its free advisory service. • Standards & specifications. The C&CI leverages its reputation as the objective authority on concrete in South Africa to exert increased influence on standards and specifications relating to concrete to ensure that it impacts positively on the use of concrete. The C&CI technical solutions team fulfills the role of custodian of all concrete related standards & specifications on behalf of the construction industry and champion quality, durability and best practice at stakeholder forums with the SABS, NHBRC and Agrément SA.

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Passive Design STRATERGIES

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Appropriate Passive Design Approaches for the Various Climatic Regions in South Africa

Dr Dirk Conradie Senior Researcher Built Environment CSIR

Introduction

Previous chapters, Maximising the Sun (Conradie, 2011) and SA Climate Zones and Weather Files (Conradie, 2012), gave an introduction of the current South African climatic characteristics. This chapter explores appropriate passive design approaches for the various South African climatic regions in detail and provide some clear answers to designers as well as the expected climate change expressed in KĂśppen-Geiger categories. In the course of my work at CSIR many people call with questions related to green design and climate. Recently an architect from Cape Town called and enquired about the possibility of using evaporative cooling in Cape Town. This is not an effective strategy in Cape Town. Direct Evaporative cooling is only efficient for about 141 hours and Two-stage Evaporative Cooling about 209 hours per annum in this climatic region. Another person from Middelburg (Eastern Cape) called in connection with massive overheating problems that he experience in his DoRegoâ&#x20AC;&#x2122;s fast food outlet due to excessive solar radiation and overheating. Investigation indicated in this case the orientation of the building is totally wrong. The lack of effective solar shading and too large unprotected surfaces of glass in this arid Karoo climate made it unbearably hot. Recently whilst passing Alexandra in the Gautrain it was The green building handbook

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noticeable how badly the large number of solar water heaters were installed. They were facing in all wind directions making the vacuum tube system used far less efficient than optimum. The use of passive design techniques are highly desirable but it is at the same time difficult to determine the most appropriate techniques or correct mix of techniques due to the variability of climate and the fact that quantified climatic data is not freely available. 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 designed for very well. To perform a quantified building performance analysis by means of simulation software not only a detailed set of quantified climatic data is required, but also knowledge of the passive techniques that is most appropriate. The climate of an area is the averaging effect of weather conditions that 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 map (Rubel et al., 2010). Today we know that the climate is constantly changing over time due to a complex interaction of factors.

Köppen-Geiger classification

While there are many different approaches to climatic classification empirical classifications such as the Köppen-Geiger classification is still 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 South African climatic conditions accurately as illustrated in Figure 1. 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. 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 1)

Table 1: Köppen-Geiger categories (Kottek, 2006) 102

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Figure1: CSIR Kรถppen-Geiger map based on 1985 to 2005 Agricultural Research Council data on a fine 1 km x 1 km grid (Author)

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Effective strategies

One of the accessible methods used in this chapter to determine the passive design strategies in the detailed Tables 2 to 12 is the bioclimatic chart that is today typically overlaid on the psychrometric chart. Bioclimatic design is used to define potential building design strategies that utilize natural energy resources and minimize energy use (Visitsak et al., 2004). This approach to building design for maintaining indoor comfort conditions was first developed by Olgyay (1963). 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 Givoni-Milne bioclimatic chart is currently used by many architects. Software such as Ecotect™ has a psychometric chart with GivoniMilne overlays. Tables 2 to 12 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 Köppen climatic regions in South Africa. The detailed tables were created by means of the advanced Climate Consultant v5.4 developed by Robin Liggett and Murray Milne of the UCLA Energy Design Tools Group with technical support from Carlos Gomez and Don Leeper. The weather files used in the analysis was generated by the Author using the Meteonorm software. The correlation between the weather file and the relevant Köppen climatic region was done by means of the high resolution CSIR developed Köppen map. The set of tables below list the set of passive design strategies per Köppen climatic region analysed for 38 representative locations. The green blocks indicate the number of hours per annum that the location would be comfortable without using any particular passive strategy. The ASHRAE Handbook of Fundamentals Comfort Model, 2005 was used. In this model it is assumed that people dressed in normal winter clothes, Effective Temperatures of

Figure 2: The original Olgyay Bioclimatic Chart with metric overlay (Olgyay, 1963)

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Figure 3: Watson and Labs Building Bioclimatic Chart, based on the original Psychrometric chart based Bioclimatic Chart of Givoni.

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20°C to 23.3°C measured at 50% relative humidity are applicable, which means the temperatures decrease slightly as humidity rises. The upper humidity limit is 17.8°C Wet Bulb and a lower Dew Point of 2.2°C. If people are dressed in light weight summer clothes then this comfort zone shifts 2.8°C warmer. The software used also supports the Adaptive Comfort Model of the ASHRAE standard 55-2004. However the latter do not provide quantified insights in the comprehensive set of strategies that the former does and was therefore not used in this chapter. The light blue blocks indicate strategies that would be beneficial more than 10% of the hours per year and could therefore be considered in the design. It should noted that the sum of the various hours and hence percentages do not add up to the total number of hours per year (8 760) because some of the techniques can be used concurrently or the applicability overlap. For example Direct Evaporative cooling could be used concurrently with Fan Forced Ventilation Cooling in Kimberley.

Aw (Equatorial, Winter Dry)

This type of climate occurs currently in only 0.2% of the surface area of South Africa. Although it is currently a small area it is very likely to expand significantly with climate change over the next century. This is discussed below. A tropical area such as Richards Bay that is close to Maputo analyzed below has a very humid climate. The most effective strategies are Sun Shading of Windows, Fan Forced Ventilation Cooling and Dehumidification.

Table 2: Quantified strategies for Köppen climatic classification Aw (Author)

BSh (Arid Steppe, Hot Arid)

16.59% of the country’s area falls within this category. If the other arid categories such as BSk, BWh and Bwk are included, 70.89% of the country’s area has an arid climate. In this hot arid region Sun Shading of Windows, High Thermal Mass, Evaporative Cooling, Fan Forced Ventilation Cooling and Passive Heat Gain strategies are most beneficial. The green building handbook

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Table 3: Quantified strategies for Kรถppen climatic classification BSh (Author) BSk (Arid Steppe, Cold Arid)

This is currently the largest arid climate type in South Africa with 23.81% of the surface area. Shading in the summer and heat gain in winter is important because it gets very cold in winter. Being an arid region evaporative cooling is also efficient in some areas indicated below.

Table 4: Quantified strategies for Kรถppen climatic classification BSk (Author) BWh (Arid, Desert, Hot Arid)

This climate type occurs in 16.29% of the surface area and is an extremely harsh climate. Sun Shading of Windows, High Thermal Mass, Evaporative Cooling and heat gain strategies in winter is beneficial. Alexander Bay is an anomaly due to the fact that it is close to the sea and the very cold Benguela sea current that change the climatic characteristics. 108

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Table 5: Quantified strategies for Kรถppen climatic classification BWh (Author) BWk (Arid, Desert, Cold Arid)

This climate type occurs in 14.2% of the surface area and is also extremely harsh with cold winters. The most beneficial strategies are Sun Shading of Windows, Evaporative Cooling and Heat Gain in winter.

Table 6: Quantified strategies for Kรถppen climatic classification BWk (Author) The green building handbook

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Cfa (Warm temperate, Fully Humid, Hot Summer)

This climatic region, only 3.7% of the surface area, is part of the warm temperate family of climates in South Africa that consists of Cfa, Cfb, Cfc, Csa, Csb, Cwa, Cwb and Cwc. Strategies that are beneficial in these high humidity areas are inter alia Sun Shading of Windows, Fan Forced Ventilation Cooling and Heat Gains in winter. Dehumidification is also beneficial.

Table 7: Quantified strategies for Kรถppen climatic classification Cfa (Author) Cfb (Warm temperate, Fully humid, Warm summer)

8.06% of the surface area falls in this category. Beneficial strategies are Sun Shading of Windows and heat gains in winter. Fan Forced Ventilation Cooling still works, but is not as beneficial as with Cfa.

Table 8: Quantified strategies for Kรถppen climatic classification Cfb (Author)

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Csa (Warm temperate, summer dry, Hot summer)

This is a rather problematic winter rainfall region that covers only 0.44% of the surface area in the Western Cape Swartland area. The only strategies that can be considered here from a passive point of view are Sun Shading of Windows and heat gains in winter. Fan Forced Ventilation Cooling contributes surprisingly little.

Table 9: Quantified strategies for Kรถppen climatic classification Csa (Author) Csb (Warm temperate, Fully humid, Warm summer)

This climate is a winter rainfall area that covers 1.59% of the surface area in the vicinity of Cape Town. Beneficial strategies are Sun Shading of Windows and heat gains in winter. Evaporative Cooling is not efficient at all.

Table 10: Quantified strategies for Kรถppen climatic classification Csb (Author)

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Cwa (Warm temperate, Winter dry, Hot summer)

This climatic region covers 2.69% of the surface area and includes the central part of Pretoria. Recommended strategies are Sun Shading of Windows, Fan Forced Ventilation Cooling and heat gains in winter.

Table 11: Quantified strategies for Köppen climatic classification Cwa (Author) Cwb (Warm temperate, Winter dry, Warm summer)

This relatively high lying climatic region covers 12.1% of the surface area and is known as the “Highveld”. It includes Johannesburg and parts of Pretoria. Strategies that can be considered include Sun Shading of Windows, heat gains in winter and to a lesser extent Fan Forced Ventilation Cooling.

Table 12: Quantified strategies for Köppen climatic classification Cwb (Author) climate change

The analyses above quantified the current climatic situation in South Africa. The current climatic conditions are illustrated in Figure 1 above. However all indications are that we can expect a significant The green building handbook

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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. In the light of the results of research of the Biometeorology group at the University of Veterinary Medicine in Vienna, the Carinthian Institute for Climate Protection in Klagenfurt (Rubel et al., 2010) and also the MIT Center for Global Change Science (Chen, 2003), the author is of the opinion that South Africa can expect a significant amount of climate change over the next 100 years. This will have a profound impact on the built environment and how buildings should be designed in future. The CSIR research team thought that if climate change could be expressed in terms of changes in the Köppen category for a particular location and building performance could be related to a particular Köppen classification it would become feasible to predict the future performance of a building within that particular location. This ambitious hypothesis was researched by first using the best available detailed weather files for 38 representative locations in South Africa. These locations were then related to the previously created CSIR Köppen map to obtain the Köppen climatic classification. The correlations between precipitation and humidity were also studied extensively, because comfort is strongly influenced by humidity and the Köppen formulas do not directly use humidity but rather functions of temperature and precipitation. Previously it was not clear what the correlation between humidity and precipitation would be. Although some correlation anomalies were observed there is generally a good correlation between humidity and precipitation especially in the higher rainfall climatic regions. The implication of this is that the Köppen map is a very good indication of the climatic characteristics within a particular climatic region. The applicability of the various passive design strategies, that would be most applicable for the said locations, was then studied using the UCLA Climate Consultant 5 software. From this clear passive design strategies emerged to address the different climatic characteristics. This is detailed in tables 2 to 12 above. From this it can be argued that if reliable weather files are available and connected or related to a particular Köppen classification it can be reasonably assumed that buildings in other areas that have the same Köppen classification will perform in a very similar way. If the appropriate passive design strategies are related to the Köppen climatic classification then the designer of today can plan ahead for expected climate change. Different climate change scenarios are available and can be expressed in terms of the expected change in Köppen category. If the expected Köppen category is known then the tables able can be used to quantify the most appropriate strategy. 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. Tables 2 to 12 indicated the current percentage distribution of Köppen categories in South Africa calculated from our study. However this is slowly changing. Advanced ocean-atmosphere coupled climate models such as the Hadley Centre for Climate Prediction and Research’s HadCM3 are currently being used in climate change studies (Wikipedia, 2011). A good example of such a study to calculate future Köppen-Geiger climatic maps is by (Rubel et al., 2010). 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 scenarios. Each scenario represents a different view of how the weather will change in future. 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 et al., 2010). The main The green building handbook

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variables in each model include population growth, economic development, energy use, efficiency of energy use and mix of energy technologies (Rubel et al., 2010). An ensemble of five general GCMs were used to simulate climatic changes, i.e. the Hadley Centre Coupled Model, the National Center for Atmospheric Research-Parallel Climate Model, the second Generation Coupled Global Climate Model, the Industrial Research Organization climate Model Version 2 and the European Centre Model Hamburg Version 4. These analyses predicted the expected climatic changes expressed as Köppen categories for South Africa over the next 100 years. Figure 4 and 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 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 1 or Table 1. Figure 4: Predicted climate change for a A1FI scenario by the year 2100 (Heterogeneous world that is fossil fuel intensive) after Rubel (2010) Figure 5: Predicted climate change for a B1 scenario by the year 2100 (World without materialism and clean technologies) after Rubel (2010)

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 the western parts of the country will progressively become hotter and dryer whilst the eastern parts will increasingly change to higher rainfall areas. The current small tropical area is likely to extend down to East London in a 100 year’s time. The in-depth analyses indicated the most appropriate passive design strategies that could be considered when designing buildings in the various climatic regions. 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 air-conditioning. The study indicates that in all climatic regions of South Africa Sun Shading of Windows is highly beneficial. 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) 116

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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 using bioclimatic principles will lead to far better “climate aware” and environmentally conscious energy efficient architecture.

References

Chen, Y-H. Estimation of Methane and Carbon Dioxide Surface Fluxes using a 3-D Global Atmospheric Chemical Transport Model. Center for Global Change Science, Department of Earth, Atmospheric and Planetary Sciences, MIT, Cambridge, MA: 2003. 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). 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. Wikipedia. 2011. Global Climate Model. http://en.wikipedia.org/wiki/Global_climate_model. Accessed 20 October 2011. Visitsak, S., Haberl, J.S. 2004. An Analysis of Design Strategies for Climate-Controlled Residences in Selected Climates. Proceedings of Simbuild 2004, IBPSA-USA National Conference, Boulder, CO, August 4-6, 2004.

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PROFILE

SOUTH AFRICAN FENESTRATION SYSTEMS (WINDOWS AND DOORS) & SANS 10400-XA ENERGY USAGE IN BUILDINGS Window technology has evolved over the past four decades to the point where windows can be selected not only for their aesthetic qualities, but also for their thermal performance abilities. For example, windows can be made from laminated glass that resists impact or have special coatings that control the amount of heat gain and loss. Windows with a “Low-E” coating are covered with an invisible film that can help keep window glass from emitting too much heat into a house. Glazing has a major impact on the energy efficiency of the building envelope. High performance (energy efficient) windows and glass are critical to a building’s energy efficiency performance. Choosing the right ‘performance glazing’ (energy efficient glass) allows one to control how much heat enters or escapes from a building. Poorly designed windows, skylights and glazed surfaces can make a building too hot or too cold. If designed correctly, it will maintain year-round comfort, reducing or eliminating the need for artificial heating and cooling. The “typical old South African” windows are notorious for unwanted heat loss and heat gain and in most cases they will not be adequate for new building designs to meet the requirements of the Energy Efficiency Regulations SANS 10400-XA Energy usage in buildings. All fenestration systems are required to be tested for air infiltration in accordance with SANS 613 Fenestration Products Mechanical performance criteria. How a window system is installed can also make a huge difference in the weather-resistant performance of the building envelope. Overcome this, by using energy efficient window and door systems which are now being built in South Africa and use only accredited installers for the best quality and performance. For existing doors install draughts seals to external side to prevent infiltration of cold air.

Air leakage clearly visible under door

“U-values” of Windows

Thermal imaging shows cold air infiltration and or leakage from underneath a door.

U-value also known as the U-factor or coefficient of heat transmission is defined as a measure of the rate of non-solar heat loss or gain through a material or assembly. U-values gauge how well a material allows heat to pass through. It is extremely important for owners and designers to make sure that they are comparing U-values for the entire window unit, (not just the glass) when selecting windows. The whole window includes glass (glazing), frame and spacers which need to be taken into consideration at design stage. The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating properties. 118

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PROFILE In 2006 the AAAMSA Group established the South African Fenestration and Insulation Energy Rating Authority (SAFIERA) to support its drive to promote energy efficiency in the building industry. SAFIERAâ&#x20AC;&#x2122;s primary goal is to provide accurate and reliable energy performance rating system. The rating system is derived from a similar system developed by the internationally recognised National Fenestration Rating Council of America (NFRC) and complies with the South African Energy Efficiency

Timber window prepared for testing in the rotatable Guarded Hot Box with Thermocouples placed strategically in accordance with ASTM C1199

Rotatable Guarded Hot Box testing fenestration systems in accordance with ASTM C1199.

Standards SANS 10400-XA Energy usage in buildings and SANS 204 Energy efficiency in buildings The energy rating process is based on the complementary use of computer simulation and physical system testing in the Rotatable Guarded Hot Box (RGHB) to establish energy performance ratings for fenestration and thermal insulated building envelope systems. The rating system is formalised by a certification programme where the products of manufacturers are certified to indicate its energy performance ratings. Typical information that would appear in the energy performance rating of fenestration systems are: the name of the company which has tested, the product range, dimensions, type of glazing, U-value, Solar Heat Gain Coefficient (SHGC), Air Leakage (AL), Visible Transmittance (VT) and mechanical

Example of Certificate issued to indicate thermal transmittance and other ratings achieved by fenestration system.

Example of aluminium sliding door being tested for mechanical properties this includes air infiltration in accordance with SANS 613

Example of timber window being tested for mechanical properties, this includes air infiltration in accordance with SANS 613. The green building handbook

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PROFILE performance criteria – class designation ranging from A1 – A6, determination of deflection, structural load, water resistance and air leakage in accordance with SANS 613. The Energy Star standard in many parts of the United States defines a maximum U-value of 2.0 W/m².K. European U-value ratings generally fall between 0.20 and 1.20 W/m².K. The local test results achieved in the RGHB falls between 1.86 and 5.78 W/m².K and can now be compared with those overseas as the testing parameters are exactly the same and whilst there are still room for improvement, it is evident that South African Manufacturers are changing window designs and achieving better results. To reduce U-factors, some manufacturers apply a low-E (low-emittance) coating to glazing surfaces. These low-E coatings reduce heat loss, improving both heating and cooling performance. Windows can also be assembled to improve thermal performance. Some assembly strategies include using two or more layers of panes or films; low-conductance gas fills between the layers, and thermally improved edge spacers, which are placed between the panes which undoubtedly makes a major impact on the thermal performance of the window system. The sash and frame of a window represent 10% to 30% of a window’s total area, depending on the window size and design. The material used to manufacture the frame can thus impact on heat loss and related condensation resistance. European design criteria are not necessarily suitable for the African climate and each design should be in accordance with the specific climatic zone. In Europe low U-values and high Solar Heat Gain Coefficients (SHGC) are applicable whereas low U-values and low SHGC’s would be more appropriate to the African climate. Windows have a large influence on the energy balance of a building and in order to design energy efficient buildings the window U-values should be calculated using the actual glazing and frame values. Local results are published on the SAFIERA website or available from AAAMSA Publications. For further information on local products tested contact the AAAMSA Group on Tel: (011) 805 5002 or visit the following websites: www.aaamsa.co.za or www.sagga.co.za or www.safiera.co.za

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Vodafone Site Solution Innovation Centre is certified 6 Star Green Star SA Office v1 Design

it pays to build green

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It Pays to Build Green

As the ‘green’ wave gathers momentum, so green-washing becomes more common practice in South Africa and the importance of having an independent body to certify green buildings, in accordance with established and agreed criteria, becomes more apparent. The Green Building Council of South Africa (GBCSA) is a non-profit organization and is South Africa’s official independent green building authority. The GBCSA not only promotes green building in the commercial property industry, but also enables the objective measurement of green building practices through developing and operating a green building rating system – the Green Star SA rating system. The number of certified green buildings, with Green Star SA ratings from the GBCSA, reached 30 by February 2013. This is a significant increase, considering that only 10 buildings were certified green in the initial 5 years between 2007 and 2011. This escalation demonstrates that green building is starting to enter the mainstream, and gaining acceptance in the built environment. However, the industry continues to battle the often touted misperception that ‘green building is expensive’. While it comes at a slight premium, the economically tangible benefits of green building far outweigh the initial costs, and this is presented in the report entitled ‘Rands and Sense of Green Building: Building the Business Case for Green Commercial Buildings in South Africa’ (R&S) – published by the GBCSA in 2012.

Aurecon Centrury City is a certified 5 Star Green Star SA v1 Office Design

While providing evidence-based South African case studies which demonstrate that green building is not as costly as perceived, it also focuses on the multitude of paybacks offered by green building.

TOP TEN ECONOMIC BENEFITS OF GREEN BUILDING

1. Energy Efficiency

Electricity prices in South Africa have increased exponentially since the power crisis of 2008, and energy efficiency (a hallmark of green building) is critical, and can have a major impact on the profitability of a company. Listed property giant Growthpoint Properties recently revealed that energy consumption has increased from R8.66/m² to R30.46/m² over the past five years, for larger office tenants. Highlighting significant scope for efficiencies to be built in wherever possible. South Africans are set for another average electricity tariff increase in 2013 as Eskom has applied for a 16% increase. This follows the rise of 25.8% in 2012; 24.8% average hike in 2011; 31.3% in 2010; and 27.5% in 2009. Making the case for energy efficiency, and alternative energy a ’must do’ and no longer a ‘nice to have.’

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Absa Towers West: One of the four gas turbines which runs the energy centre. By not utilising energy off Eskom’s grid, Absa will reduce its carbon dioxide emission by an estimated 19 000 tons a year

Energy efficient buildings also minimize the strain on infrastructure. In some cases - such as the Absa Towers West: Green Star SA rated office building in Johannesburg CBD, which houses a tri-generation plant to produce power for the campus – self supply of power not only reduces carbon emissions through use of natural gas, it also lessens the stress on Eskom infrastructure, and allows for expansion in an area where additional power supply is simply not an option.

Naturally lit stairwell at Nedbank Ridgeside

2. Productivity Increases

Improved Indoor Environmental Quality (IEQ – a requirement of green buildings) with its focus on temperature; air quality; light; noise and space, relate to productivity increases from staff. Fewer sick days are taken, and job satisfaction increases. 126

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When green building expert Jerry Yudelson spoke at the 2012 GBCSA Convention in Cape Town, he encouraged companies to pay particular attention to this point, noting that much more is spent on salaries than on rent. Efficiencies among staff are difficult to quantify, but very worthwhile. Another speaker at the 2012 Convention, Sustainable Property researcher Dr. Nils Kok emphasized that companies spend 100 times more on salaries than they do on energy, and on average, ten times more on salaries than rent. The benefits are also being yielded outside of traditional ‘office space’ such as in retail environments, where higher retail sales are being recorded in green buildings. Research by Yudelson shows evidence of increased sales in retail spaces from daylight harvesting alone, averaging 5%. In South Africa, the Pick n Pay on Nicol store, which boasts a number of sustainability initiatives, is an example of this. The store has experienced continued growth by customer numbers and sales. In fact, the shopping basket value at this store is more than double the average, and the basket size is bigger than the average. South African retail giant Woolworths has also adopted a more holistic approach to green design in their new stores, with emphasis on natural lighting, CO2 refrigeration, and visible electricity meters. Feedback from customers is that this enhances the shopping experience, while 30% savings in energy costs have been achieved with payback periods of about 3.5 years for green initiatives.

3. Higher Re-sale Value

Confirmation of ‘green premiums’ on the market value of green buildings continues to be recorded. Research outlined in R&S shows that green buildings in the US (LEED certified) on average fetch transaction price premiums of 11%, while in Australia the figure is 12% higher market value recorded for Green Star rated buildings compared with similar, non-certified properties. Kok’s research has also shown that globally (including Europe) certified green buildings have displayed higher resale transaction prices of 13%.

4. Higher Rents Reclaimed

The R&S cites a report entitled ‘Sustainability and the Dynamics of Green Building – New Evidence on the Financial Performance of Green Office Buildings in the USA’, which concludes that the effective rental rates of commercial property are markedly higher in green buildings. Kok’s research also shows that, (using like for like comparisons) green buildings fetch higher rent by about 3%. This is owing to the numerous benefits realised by the tenants of a green building, such as increased productivity, lower operating costs, and a greater ability to retain and recruit sought-after staff.

5. Increased Tenant Value

Tenants of green buildings are more likely to renew their lease in a well-operated green building. There is also increasing demand for green buildings from tenants. Kok’s research shows increased effective cash flows in certified green buildings, with an average 7% higher occupancy. Further, R&S references a study entitled ‘Green Value: Growing Buildings, Growing Assets’, which found that green building certification enhances an asset’s value as it allows property owners to secure tenants more quickly, and experience lower tenant turnover. The green building handbook

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Certified green buildings are also more able to attract and retain desirable corporate and government tenants, which will likely have increasingly stringent criteria for building performance going forward.

6. Reputational & Marketing Benefits Investors are demanding greater disclosure, accountability and responsibility from companies, and more responsible investment standards are being introduced.

By seeking a green building certification, investors can be assured that a company has been measured with independent criteria, by an independent body, and the property in question has met certain environmental requirements. It demonstrates a commitment to green building principles, which shows concern for people and the environment as well as bottom line efficiencies. The public perceives green buildings as modern, advanced, dynamic and altruistic, and organisations associated with these buildings will reap the benefits from these. The Green Star SA rated buildings profiled in the case studies of R&S noted increased media coverage and industry awareness as a result of their green initiatives and Green Star SA certification. Although often difficult to quantify, buildings that pursue a GBCSA rating at an early stage, do so knowing that the reputational benefits will be advantageous. Prior to its submission, Amdec (developer of multi-unit residential apartments within Melrose Arch in Johannesburg) had not anticipated the kind of marketing and publicity ‘Forty on Oak’ would receive – it generated over R360 000 of free Advertising Value Equivalent within six months of achieving the accolade of the ‘first Green Star SA rated multi-unit residential development’.

7. Recruit & Retain Talent

Richefond Circle proudly displays its 4 star Certification

Exceptional employees are in limited supply in today’s competitive market. To attract key individuals, Yudelson highlights that a company must show commitment to issues of relevance to staff. This includes reputation of a company, as well as the quality and health of the working space offered to employees. 128

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8. Reduced Liability & Risk

Environmental issues are proving to have economic impacts, for example through the insurance industry as a result of threats from resource scarcity and climate change. Another example is the possible introduction of a carbon tax in South Africa. By incorporating sustainable features immediately, building owners are â&#x20AC;&#x2DC;future proofingâ&#x20AC;&#x2122; for changes in the business and regulatory environment, and protecting themselves from possible environmental impacts. Taking cognizance of the risks pre-emptively ensures that buildings will not be uncompetitive in the future. The need for costly retrofits in the future is averted, as well as possible legal action resulting from employees suffering after being subjected to inferior IEQ.

9. Operational Cost Savings

The increasing cost of electricity in South Africa is accompanied by the steady rise in the cost of other services such as water and solid waste removal. Green buildings reduce the amount of water used in a building, and well-run recycling programmes within a building ensure that there is less waste to landfill and more recycling taking place, which can have economic benefits. In addition fewer resources are used in the first place, as the management criteria of a green building, ensures that resource-efficient programmes are put in place.

Waste solutions at Nedbank Phase ll

10. Expansion of Green Products and Services Markets

By committing to achieving a Green Star SA certification, a company commits to using more sustainably sourced and manufactured products and materials for their building.

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This helps to grow the industry in South Africa as it boosts the demand for individuals and companies with ‘green skills’, and ensures that there are markets for green products. Costs thus become more cost-competitive. These goals are in line with the government’s objectives within the Green Economy Accord to bolster ‘green’ manufacturing and services and create ‘green jobs’ in sustainable industries.

AN EVOLVING MARKET

As greener products and services become more readily available, professionals, property owners and developers begin to subscribe to the numerous health, environmental, social and economic benefits of green buildings, we see the whole property industry transforming towards a lower carbon-path and ultimately environmental sustainability. Regulation is catching up to Green Star SA standards, and the ratings tools will continue to raise their benchmarks, and recognise the leaders. The GBCSA continues to work on the number and range of rating tools available, with a Green Star SA - Interiors rating tool and a Green Star SA - Performance rating tool on the cards for development and release in 2013. These tools are set to be ‘game-changers’ because until now the GBCSA has focused on the certification and rating of new ‘whole’ buildings and major refurbishments only, which accounts for just 1-2% of the average property portfolio. To truly minimise the impact of buildings on the environment, existing buildings, and tenant interior fit-outs must be considered. Current rating tools available to the market: Office v1; Retail Centre v1; Multi-Unit Residential v1; Energy & Water Benchmarking PILOT and the Public & Education Building v1 rating tool. Certification is becoming easier as the number of Green Star SA accredited professionals with certified project experience increases. The GBCSA continues to expand its educational course offerings, as part of their commitment to improving the knowledge and skills base of green building in the industry. The GBCSA also continues to conduct research on green building, and produce reports to raise awareness of green building in South Africa, and importantly dispel myths that exist surrounding green building. The market is changing and the realization is dawning that while there is an ecological imperative to improve the environmental impact of the built environment, doing so can yield many more benefits reflected in the traditional bottom-line.

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GREEN STAR SA CERTIFICATIONS (September 2012) 1

Nedbank Phase II

4 Star Green Star SA Office v1 Design

Nedbank Phase II

4 Star Green Star SA Office v1 As Built

Villa Mall

4 Star Green Star SA Retail Centre v1 Design

Nedbank Ridgeside

4 Star Green Star SA Office v1 Design

24 Richefond Circle

4 Star Green Star SA Office v1 Design

24 Richefond Circle

4 Star Green Star SA Office v1 As Built

Aurecon Centre Tshwane

4 Star Green Star SA v1 Office Design

Aurecon Century City

5 Star Green Star SA v1 Office Design

Nedbank Menlyn Maine Falcon Building

4 Star Green Star SA Office v1 Design

Vodafone Site Solution Innovation Centre

6 Star Green Star SA Office v1 Design

Forty on Oak

4 Star Green Star SA Multi Unit Residential PILOT Design

Mayfair on the Lake

4 Star Green Star SA Office v1 Design

Lincoln on the Lake

4 Star Green Star SA Office v1 As Built

Upper Grayston Office Park, Building E

4 Star Green Star SA Office v1 Design

SANRAL Corporate Head Office

4 Star Green Star SA Office v1 Design

Millennia Park

5 star Green Star SA Office v1 Design

ABSA Towers West

5 Star Green Star SA Office v1 As Built

New Sisonke District Offices

5 Star Green Star SA Office v1 Design

Eastgate20

4 Star Green Star SA Office v1 Design

City of Cape Town

4-Star Green Star SA Office v1 Design

Electricity Head Office

5 star Green Star SA Office Design v1

Standard Bank Rosebank

4 Star Green Star SA Office Design v1

City of Cape Town

4 Star Green Star SA Office Design Rating v1

Mannenberg - Human Settlements

4 Star Green Star SA Office Design Rating v1

115 West – Alexander Forbes

5 Star Green Star SA Office As Built Rating v1

Softline VIP Menlyn Maine, Epsilon

4 Star Green Star SA Office Rating v1

Upper Grayston, Office Park, Block E

4 Star Green Star SA Office Rating v1

Nedbank Ridgeside

4 Star Green Star SA Office Rating v 1

Mayfair on the Lake

4 Star Green Star SA Office Design v1

Agrivaal – Department of Public Works

4 Star Green Star SA Office Design v1

No. 1 Silo – V & A Waterfront

6 Star Green Star SA Office Design v1

Alice Lane Phase 1

4 Star Green Star SA Office Design v1

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GREEN BUILDING COUNCIL OF SOUTH AFRICA - FACT SHEET

• Established in 2007 by leaders from all sectors of the commercial property industry • An independent, non-profit, membership-based organisation • Focus includes new or refurbished commercial building applications, multi-unit residential, retail, public and education buildings, and more recently interiors and existing building stock. • The GBCSA currently has: • 30 Green Star SA certifications • 400 accredited professionals • Over 3000 have attended GBCSA courses • Over 1000 member companies • Is a full member of the World Green Building Council

GREEN STAR SA TOOLKIT

• • • • •

Office v1 Retail Centre v1 Multi Unit Residential v1 Public and Education Building v1 Energy and Water Benchmarking PILOT tool

GREEN STAR SA FAST FACTS

• Green Star SA is South Africa’s officially recognised green building rating system • It exists to prevent buildings being paraded as green when they are not, ie. green washing • Based on the Australian Green Building Council tools, it was developed by the GBCSA, together with the input of a local stakeholder group of industry experts • Comprises eight green building categories: management, indoor environment quality (IEQ), energy, transport, water, materials, land use & ecology, emissions, innovation • A new category tackling socio-economic issues in design and construction has been developed and will be offered with the Green Star SA tool in 2013 • Certification can be achieved for ‘Design’ (tender stage) and ‘As Built’ (practical completion stage) Certified ratings: • 4 Star Green Star SA: Best Practice (45 - 59) • 5 Star Green Star SA: South African Excellence (60 – 74) • 6 Star Green Star SA: World Leadership (75 – 100)

GBCSA FOUNDING MEMBERS

• SAPOA • Spire Property Group

GBCSA PLATINUM FOUNDING MEMBERS

• • • • •

Growthpoint Properties Ltd Old Mutual Property Capicol Grohe Eskom

Contact Details:

For further information, visit www.gbcsa.org.za or contact: Green Building Council of South Africa I Rosanne Mitchell - Marketing Executive 0861 042272 | rosannem@gbcsa.org.za

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MANUFACTURERS OF FABRICS FOR ROLLER BLINDS VERTICAL BLINDS Our FABRICS are FULLY WASHABLE

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PROFILE

Vrede Textiles Vrede fabrics is the finest woven blinds fabric created from a unique intergrated composite spun yarn that results in a high performance, stable and non-fraying textile perfectly suited to vertical, roller, roman, holland and conservatory blinds. Buildings account for almost half of all energy consumption and CO² emissions. As the drive to cut carbon emissions gathers pace, cost effective ways of reducing energy consumption are being sought. In a typical office building lighting, heating and cooling represent approximately 65% of energy use. Our woven blinds fabrics have an important role in improving energy efficiency. It is widely recognized that more than double the amount of energy is required to cool a room than to heat a room. A correctly specified window blind will not only reduce solar gain but also allow good levels of natural light, resulting in dramatic reduction in air conditioning and artificial lighting usage. In winter and at night, window blinds act as an insulator, reducing the amount of warm air escaping the building through the glass thus reducing the strain on the buildings heating system. Our woven blinds fabrics are a cost effective solution that can have a big impact. By reducing carbon emissions, not only are you doing your bit towards a sustainable future you will also enjoy the benefits of a reduction in energy costs and an increase in productivity as a result of an enhanced working environment. The versatility of vertical/roller blinds is well known. Not only do they offer aesthetic enhancements to your rooms but they can also offer privacy, light control and protection for valuable furniture, furnishings, flooring etc. When installed in conservatories, for example, they make the space feel more homely. A wide range of fabrics in plain and pretty patterned styles are available in many colors. When you use vertical/roller blinds on a large scale application, like covering sliding glass patio doors, you effectively diminish the amount of heat transferred through sliding glass doors Whether it’s retaining heat in the winter, shading the sun’s rays in the summer, or providing maximum UV blockage and sound absorption, proper window coverings can substantially cut your energy costs and improve comfort levels and overall décor. The result is a surprisingly early return on investment and a refreshing new look you will enjoy for years to come. 134

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PROFILE

Belgotex Floorings Belgotex Floorcoverings operates a ‘green’ factory and is ISO 14001 Environmental Management System certified. Product development is increasingly geared toward solution-dyed fibres and yarns over postdyed materials due to their more preferable dry production process which reduces water, chemical and energy consumption. Several products are made using recycled material while factory waste is in turn reused by other manufacturers as post-industrial recycled content in the production of their products. Bestselling BerberPoint 920 is made with varying percentages of recycled facefibre and 70% recycled content (fly-ash) in the backings of NexBac Eco modular ranges is available on request. Belgotex Carpet’s Reclamation programme collects used carpets which are cleaned and sent to charity organisations such as Wildlands for reuse and redistribution so they don’t end up on a landfill site. All Belgotex products bear the company’s Environmental Choice logo for eco-friendly flooring and production processes.

Contact Details Belgotex Floorcoverings Tel: 033 897 7500 Website: www.belgotexfloorcoverings.co.za or www.environmentalchoice.co.za The green building handbook

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Case Study: Bio-Climatic Building Design for Tropical Climates

Antoine Perrau Architects LEU Réunion Environemental Quality Department Environmental design in the humid tropics requires special consideration. This chapter is based on two case studies which attempt to develop a practical approach to including key elements of bioclimatic design in tropical regions. Location: Reunion Island Population 840,000 inhabitants Area: 2512km ² Geology: Volcanic island Highest point: Mount des Neiges 3070m Rainfall: Reunion holds all world records for precipitation between 12 hours and 15 days

Figure 1: Geographic Location of Reunion Case Study 1 Malacca Flores: Promoter: SIDR (Semi-Public Social Housing) Architects: Michel Reynaud / Antoine Perrau Environmental quality department: LEU Meeting City: Le Port Altitude: 10 m leeward coast Delivery: 2011 Total floor area: 8950 m² The Context: The green building handbook

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The project is located in a Development Zone and the objectives include: opening the city towards the sea, to reinvigorate the city centre, create a link between the periphery and centre of the community, and to implement the principles of sustainable development through a green master plan. The projects location and surroundings were thus crucial to its success. The Site: The site of a project and its concomitant micro climate is of particular importance in the tropics. Favourable conditions on site will impact the performance of buildings constructed there.

For instance the presence of trees plays a fundamental role in the areas micro-climate. Our firm’s offices are in the centre of the island, allowing us to illustrate these differences. During February, the month with the highest temperatures in the Southern Hemisphere, a temperature differential of 7 ° C was measured between the street and the inside of the office (without air conditioning). This is achieved in part, by planting buffers of vegetation such as grass and shrubs between the street and the building. The effect of the plants is to cool the air through evapotranspiration, and reduces the albedo effect by shading the concrete and other hard surfaces.

Figure 2: Office veranda and adjacent garden shielding the building from the street The role of plants in reducing the urban heat island effect has also been demonstrated in the city of Paris by researchers from Météo France. The diagram below illustrates the difference in temperature between the suburbs and the city center during a summer’s day, which was 4 ° C. 140

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Figure 3: Temperature differentials in Paris Source: The Journal of Research We therefore sought a favourable site for the project, and special effort was taken to re-vegetate surrounding buildings and find space on natural land.

Figure 4: Project Location Shading: The second step was to determine the most favourable orientation of the shading devices through computer simulations of sunscreen designs.

Figure 5: Modeling Efficacy of Sun Shading Devices The green building handbook

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Parallel to this reflection, we verified the thermal comfort. It should be noted that the concept of comfort temperature is different from the temperature measured with a thermometer and is not absolute but depends on several parameters: humidity, air velocity, air temperature, the radiation

Figure 6; Factors Influencing Thermal Comfort

temperature of the walls, metabolism and clothing. One can evaluate the effect on internal comfort of a building as influenced by the first four factors mentioned above using the comfort graph developed by Givonni:

Red air velocity of 1m / s Yellow air velocity of 0.5 m / s Green air velocity of 0m / s

Figure 7: Givonni Chart The graph demonstrates how essential it is to ensure natural ventilation, which is achieved through the porosity of the facades, and in this latitude, there should be a minimum porosity of 20% between two opposite facades. Effective implementation of these interventions allows urban and architectural buildings to reduce their energy consumption by between 28 and 41 kWh / mÂ˛ / year. In fact spaces designed in this way provide thermal comfort without the need for air conditioning, even in the tropics.

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Figure 8: Cross Ventilation Additional features: Beyond these provisions, the specification proposes a number of other environmental features: Implementation of solar hot water panels and photovoltaic roof panels These panels are also used to shield the roof from high levels of solar radiation. 70% of the heat input comes through the roof, and so this element of the design should be treated with the utmost consideration and care.

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This dual purpose of the solar devices can increase their efficiency and reduce overall cost. Increased use of wood to reduce the carbon footprint of the project Wood was specified for the structure of corridors, sidings, sunscreens and pergolas.

Figure 10: Timber Material Choice Grey water recycling We used a filtration system with a settling tank and a filter zeolite vertical which provided regular contributions of water for irrigation.

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Figure 12: Ariel View of Completed Project Case Study 2 National Park House of RĂŠunion

Figure 13: Images of Proposed Development

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Promoter: National Park Meeting Architects: Michel Reynaud / Antoine Perrau City: The Plain Palm Altitude: 1050 m Delivery: 2013 Work in progress The context: The context here is very different from the first project as the site is located in the centre of the island, a mountainous area at an altitude of 1000m. The challenge therefore was to achieve conditions of human comfort in respect of both heating and cooling as the area can get very cold in winter.

Figure 14: Site Plan This region is characterized by heavy rainfall, prevailing winds from opposite directions and a high quality bio sphere with many endemic species. A key objective was to organise the buildings in a manner that least affected the surrounding, and this was achieved in part by building on narrow stilts. The effect is to preserve flora at the forest floor and allow for the movement of animals and insects, and at the same time creating opportunities for natural ventilation. The position of the site within the surrounding environment is highly favourable due to the existence The green building handbook

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of plants and trees, and the objective here was to preserve and thus take advantage of the micro climate and its characteristic albedo and thermal regulation. The Building The environmental strategy was focused primarily on the following topics: thermal comfort in summer and winter, optimised natural lighting, optimisation of one unit energy consumption, water treatment, storage of COâ&#x201A;&#x201A; with the use of wood and ecological restoration of the site. Thermal comfort As mentioned above the altitude of the location has led us to consider two strategies utilising two thermal and different operating modes to achieve comfort in summer and winter. Moreover, given the non-permanent occupation of the premises (offices and exhibition) we focused on comfort during periods of occupancy and have implemented climate zoning to optimise shading and natural ventilation devices to optimise different thermal comforts. The strategies employed are: Workspace: Control of hygrothermal conditions (Controlled Mechanical Ventilation dehumidification) Circulation: Buffer space (cold in winter - warm in summer) Large volume space: passive functioning + wood stove Technical / Sanitary spaces: ventilation + humidity control

Figure 15: Building Configuration Summer comfort: The founding principles here are similar to those mentioned in the previous project: input controls such as shading on the building and effective ventilation to maintain a comfortable temperature. 148

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To obtain satisfactory results we have taken the following steps: -Dry construction to limit thermal storage in the walls -Good thermal insulation of the roof (remember 70% of heat gain through the roof ) -Good porosity of the facades, to optimize the ventilation -Buffer thermal circulations positioned to the North A Trombe wall consisting of polycarbonate tubes filled with water acting as sun protection and cold tank thermal inertia was also used.

Figure 16: Summer Comfort Strategies Winter comfort A major goal here was not to have to mechanically regulate heating and to minimise the high humidity discomfort factor. To obtain satisfactory results we have taken the following steps: - Dry structure to limit cold wall effect - Good insulation to walls - Fenestration: all closed but may be opened for localised temperature - North passageway bioclimatic greenhouse to optimize solar radiation - Trombe wall water Heat diffusion, thermal inertia tank - Double flow CMV with dehumidification and air preheating new Trombe wall The sun warms the tubes filled with water in the morning, through solar radiation, and heat in the water is distributed throughout the height of the tubes by convection which then returns the heat to the air. In Reunion clouds very often appear in the afternoon which assists this process. The green building handbook

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Figure 17: Trombe Wall

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Energy Efficiency A careful selection of technical equipment and lighting allowed us to obtain the following energy balance as set out in the Table below:

Table 1: Technical Equipment and Lighting

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This table also highlights the importance of verifying assumptions and therefore the need to monitor the building to ensure compliance with the assumptions. Construction system The construction system has introduced a dual use of the building facade so that the structure minimises the carbon footprint of the project while reducing the impact of building on the site by taking it off the ground and thus preserving the transparency and hydraulic corridors and embracing the surrounding ecological environment as well as mimicking the surroundings.

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Figure 18: Section and Elevation Ecological restoration: This project also provided an ambitious ecological restoration of the site with the preservation and planting of endemic species which constitute the World Heritage of UNESCO that is Reunion. Conclusion The two case studies demonstrate how designing with the bioclimatic conditions of a site can enhance the performance of the building while simultaneously enhancing the ecological value of the site. It is a clear indication that it is possible to undertake developments while supporting ecosystem resilience.

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PROFILE

Eastern Cape Top Green Organisation Award Winner 2012

Langkloof Bricks, the pioneers of Vertical Shaft Brick Kiln technology in South Africa, have invested and created one of the most energy efficient clay brick firing systems in the world. The VSBK reduces Green House Gas Emissions and coal usage by up to 50%. The first South African six shaft VSBK was constructed, commissioned and inaugurated in late 2011 at Langkloof Bricks. The proven VSBK system of firing clay bricks now gives the South African brick industry an environmentally viable alternative to the original method of firing bricks in clamps. At Coetzee, the Executive Director of the Claybrick. org says, â&#x20AC;&#x153;The VSBK Project is a brilliant example of how local expertise can partner with international knowledge leaders to benefit an entire industry and country. This will have lasting benefits for our members, their employees, the environment and our country for many decades to come, thereby enhancing the benefits of building with clay brick which is already proven to be the most sustainable building material for us in housing in the South African climate.â&#x20AC;? These reductions in emissions will lead to improved quality of air and thereby improved quality of life. See chart below for energy usage for brick firing technology currently used in South Africa. We should also note that a common brick weighs approximately 2.6 - 3.1 Kg after being fired. Energy Comparison usage chart:

The VSBK technology allows a dry green brick to be fired/vitrified in 24 hours, it is the fastest and most efficient clay brick firing system in the world. Our products are thoroughly fired throughout to give strength and durability and a warm aesthetic appeal. 156

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Since changing from the old clamp firing method to the new VSBK technology, Langkloof bricks will save 3193 tons/ annum of coal and contribute to the reduction of CO2 emissions of 6822 tons/annum. This energy saving also negates 94 loads of coal at 34 tons/load being road hauled 225,000 kilometres in round trips, a further commensurate benefit for the environment. There is no doubt in our minds that VSBK technology is one of the most energy efficient and cost effective brick firing processes in the world, with the added benefit of providing a better working environment for our staff members. We believe the VSBK technology will fundamentally shift the way many clay brick manufacturers think about production in the future, from an economic, social and environmental perspective. The VSBK technology shows that environmental protection can also be a stimulus for economic growth! This project is a perfect example of how the private sector can contribute in climate change mitigation while increasing economic competitiveness in the market. By reducing the embodied energy required in our brick production, our clay bricks offer the building industry a truly green alternative to other building products. Clay brick has real longevity, is completely recyclable, totally inert after vitrification (no release of CFCâ&#x20AC;&#x2122;s or other harmful compounds or gases). Other benefits include high thermal mass, excellent sound insulation properties and lower carbon footprint over the life span of the product. Our company is currently engaged in planning to further lower our energy requirements throughout our business.

DEDEA & IWMSA Eastern Cape Top Green Organisation Awards 2012 1st Place Small Organisation With High Environmental Impact Head Of Department Innovation Award Tel:042 293 5872 sales@thebrickcentre.co.za www.langkloofbricks.co.za The green building handbook

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24 - 25 July 2013

At the first Green Building Conference 7 years ago the key issues that building designers needed to address were energy, water and resource efficiency; and human and environmental health. Sharing knowledge and developing competence in these key building performance indicators remains the focus of Green Building 2013, but with some stark differences in intensity and focus. Enough has been said about global context, policy and advocacy - Green Building 2013 will focus squarely on the implementation of design strategies and the specification of materials and technologies empowering delegates to commission, design, construct and operate buildings that achieve and exceed specific standards and objectives:

Module 1 Morning Session 09h00 - 09h30 Opening 09h30 - 10h30 Master class by Prof Charles J. Kibert on Design for Net Zero Buildings 10h30 - 11h00 Questions & Answers 11h00 - 11h30 Tea 11h30 - 12h30 Master Class by Glenn Murdoch, Chairperson Passive House Institute New Zealand on Passive House Design 12h30 - 13h00 Questions & Answers 13h00 - 14h30 Lunch and expo tour

Module 2 Afternoon Session 14h30 - 16h00 Six short presentations on how to achieve EE standards using different materials and technologies (15 minutes each): • Solutions using: concrete, steel, brick • Insulation • Lighting • Building Performance Modelling 16h30 - 17h00 Panel discussion on how to fit technologies together in a building 17h00 Networking Function

Module 3

Morning Session

Module 4

Afternoon Session 14h30 - 16h00

International Expert - Master Class on water efficiency in buildings

14.00 – 14.25 Enrico Daffonchio, Daffonchio and Associates – Case Study on Energy Works, Parktown North

10.00 - 10.30 Q&A

14.25 – 14.50 Kate Otten, Kate Otten Architects – Case Study on Lulu Kati Kati Melillo

9.00 - 10.00

10.30 - 11.00 Tea 11.00 - 12.00 Graham Young, University of Pretoria Mater Class on Landscape Architecture 12.00 - 12.30 Q&A 12.30 – 13.30 Lunch and expo visit

14.50 – 15.15 Anna Bailey, Claude Bailey Architects Case Study on House Kavuma, Lanseria 15.15 – 15.40 Steve Kinsler, East Coast Architects – Case Study on Vele Secondary School, Limpopo 15.40 – 15.05 Jaco Burger, Project Manager City of Ekurhuleni - Case Study on OR Tambo Cultural Precinct, Benoni 16.05 – 16.30 Activate Architects – Case Study on Lebone II College, Phokeng 16.45 – 17.30 Informal Q&A at the Expo Stage

SUSTAINABILITY 2013 WEEK SANDTON CONVENTION CENTRE – 23 - 28 JULY

book your seat now at alive2green.com/green-building-booking-form/ or simply email us on bookings@alive2green.com, call 021 447 4733

PROFILE

Riaan Steyn Architects

STAND 1557 – WATERFALL ESTATE SHOW HOUSE.

Riaan Steyn Architects was approached to design a house with a total floor area of 550m². Along with Large, comfortable, open spaces and a permeable external skin - capable of being manipulated to capitalise on the views offered by the site’s natural vegetation. In order to achieve and maintain sustainable outcomes; identified throughout the planning phase of the project; influences relating to site context, site location and the project budget were critically observed. Gas geysers for hot water appliances have been specified rather than solar geysers and solar collectors. The estate is supplied with reticulated LP Gas which allows for reduced gas expenses as well as the opportunity to size larger usage specific gas geysers, for the bathrooms. Other features include the under-floor heating, whereby floor surfaces are warmed by the heated water-filled pipes, laid in the screed. The water is heated via gas which adds to the unique status of the system Energy efficient LED lighting is also proposed throughout the house. LED lights have a longer life expectancy compared to their incandescent competitors. They are also unaffected by voltage fluctuations on the grid as opposed to CFL lighting. The passive energy systems that have been implemented within the design of the house allow for energy efficiency with regards to daily living activities. Emphasis on electrically driven appliances has been eradicated by ensuring temperature comfortability through natural means and my making use of alternate water heating and lighting systems. In an attempt to improve the design’s “green” status, passive design techniques were successfully implemented to ensure that the reliance on external, mechanical systems would be reduced.

Company Name: Riaan Steyn Architects Contact Person: Riaan Steyn Contact Number: +2711 339 5022 Email: info@rsarc.com • Website: www.rsarc.com 160

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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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Department of Environmental Affairs (DEA) – New Head Office Case Study A National Commitment to Sustainable Buildings

Michael Aldous (Pr.Tech.Eng) Associate Director Head: Green Building & Sustainability Services PD Naidoo Consulting Engineers

Introduction

The Department of Environmental Affairs (DEA) is mandated to ensure the protection of the environment and the conservation of natural resources within the context of sustainable development. In this regard the DEA is guided both by its constitutional mandate, prevailing legislation, and relevant international agreements to ensure that all South Africans have a right to a clean environment that is not harmful to their health or well-being, and that the environment be protected, for the benefit of present and future generations as entrenched in the Bill of Rights of the Constitution of the Republic of South Africa (1996). The DEA has set in motion a process to lead in the area of renewable energy, energy consumption, water conservation and current environmental considerations through the head office being housed at a location that gives life to these aims; a “Green Building”. The head office development has been implemented in terms of a Public Private Partnership (PPP). The consortium tasked with the development is the Aveng Grinaker-LTA-Keren Kula DEA Joint Venture. The DEA is committed to ensuring that a continuous process occurs to ensure awareness and action on matters impacting the environment; as such the project has fully committed to achieve exemplary leadership through joint efforts with the departments of national government in an effort to substantially contribute to broader market transformation across all spheres of national and local influence, while leveraging bilateral international relationships in respect of environmental protection. Figure 1 provides and artist’s impression of the new entrance to the DEA building.

Fig. 1: The new green centric DEA Head Office, City of Tshwane Image: Boogertman + Partners Architects (Pretoria)

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Locality, Climatic & Urban Context

The development is located in close proximity to central Pretoria, bounded by Steve Biko (formerly Beatrix) and Soutpansberg Roads in Arcadia and within the previously approved Gauteng Urban Edge (2002). The development of the area pre-dates 1940 and as such falls well within the current developed footprint of Tshwane and is the redevelopment of previously developed land that exhibited an overall Present Ecological State (PES) that was low and highly degraded. The significance of the site selection allowed for the construction and rejuvenation of land without contribution to continued urban sprawl and provided access to viable existing municipal infrastructure. The impact of urban sprawl and decentralization are highlighted by Horn (2009) and it is within this context that the DEA building has focused on the redevelopment of a previously utilised site as a commitment to leadership by example. In addition to urban rejuvenation the locality played an important role in determining the applicable climatic conditions upon which modelling and analysis of the building performance were based particularly given that Pretoria, based on the revised KĂśppen-Geiger classification information presented by the CSIR by Conradie & Kumirai (2012), shows three climatic regions in the vicinity of Pretoria, each requiring varied passive design responses. The site is in close proximity to two Meteonorm data sources and these provided a localised basis for performance modelling in the absence of any higher resolution long term weather data

Building Form

The building concept comprised three distinct elements; the central reception building, the office wings and the bridge structure connecting the elements together. The nautilus shell concept as one of natureâ&#x20AC;&#x2122;s timeless shapes was used as inspiration for the design of the Central Arrival Space and ministerial wing. The shape of the building with optimised north orientation and narrow floor plates with atrium provided positive indoor benefits in terms of light and space. The Main Office is comprised of three wings to the south and two shorter wings to the north of the site, the regular form and repetition improves constructability and minimises potential wastage. The structure is expressed externally in the form of a concrete frame that provides shading, with offshutter finishes intended to reduce maintenance and introduce an aspect of dematerialisation by means of reduced finishing required. Decorative screens on the facade serve a dual function as aesthetic and functional solar shading devices, supporting energy efficiency through reduced thermal loads in conjunction with glazing placement and envelope design.

Fig.2: A Rendered View of the New DEA Head Office Image: Boogertman + Partners Architects (Pretoria)

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Fig.3: The DEA Head Office â&#x20AC;&#x201C; Building Form and layout Image: PD Naidoo & Associates, Integrated Design Approach

The international Energy Agency (IEA) highlighted the short comings of the traditional design process (Larsson and Poel, 2002) and it is within this context that the benefits of an Integrated Design Approach become apparent in the delivery of a project that is able to fulfil the environmental performance requirements as well as achieve occupant satisfaction. The DEA project underwent a detailed evolution with conceptual design focusing on the optimisation of environmental performance from the outset with the professional team adopting an iterative approach to the building fabric and systems, rather than the linear approach common of traditional design. The project relied on the integration of a high level of skill early on in the design process driving open communication and synergy supported by leading simulation and analysis tools as identified by Larsson and Poel, (2002). In order to maximise the available design options the influence of major factors impacting building performance were simulated by the design team for various proposals and combinations, starting with basic geometry and progressing to detailed building form from which a cost / performance benefit analysis determined the finally adopted strategies within the project brief parameters. The combined benefit of the design has resulted in a modelled building that significantly exceeds the requirements of the revised SANS regulations. The outcome of this process has been a design optimised and fine-tuned through repeated interrogation and iteration to meet the expected environmental performance outcomes.

Key Building Features

Daylight and Lighting Controls: The project was subject to a stringent energy target that assigned a maximum allowable energy consumption per square meter per annum, in order to meet this target. Given that lighting has been identified as contributing between 30 and 45% of the energy demand of a commercial building (DiLouie, 2005), the building incorporated extensive lighting controls that featured occupancy sensing, continuous dimming, addressable lighting components, photometric based control and integration with the Building Management System (BMS). The lighting solution maximised the use of natural daylight where possible as indicated in (Fig.4). The 166

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image highlights the extent of natural lighting intensity within the occupied and common zones on the typical second floor of the building, allowing for a visual assessment and design refinement. As detailed by Phillips (2004) the impact of daylighting has extensive positive benefits in occupant wellbeing, health and energy savings, thus serving as a key consideration in design optimisation. The lighting controls have been designed to maximise the zonal nature of the light distribution from the perimeter inwards and make use of a full dimmable DALI control system. Each fitting was designed to be capable of dimming in response to lighting levels and defined control scenarios. The design sky adopted for analysis purposes refers to a simplified approximation of the sky luminance for the purposes of modelling daylight over a period of time. Various sky types exist and are continually evolving as computational capacity grows.

Fig. 4: Natural daylighting levels across the typical office floor plate under design sky conditions indicating areas with sufficient natural light to minimise artificial lighting for part of the operating hours of the building. Image: Solid Green

Fig. 5: The energy impact of daylight harvesting with continuous dimming under different glazing VLT scenarios Image: Solid Green

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The lighting control design was conducted in close concert with the selection of glazing materials as the impact of visible light transmission (VLT) was a key determinant in faĂ§ade glazing selection. The benefit of the lighting and glazing selection strategy is evident in Fig. 5, the grey line indicating a standard lighting control on/off scenario, and coloured lines representing the various combinations of VLT glazing in combination with dynamic continuous light dimming. The impact of the lighting control and glazing highlight the imperative for cross discipline integration in order to maximise the final energy demand profile; by synergising faĂ§ade and lighting the net benefit result is achieved in the lighting example provided. Based on the modelled data the energy savings attributed to glazing and lighting control design showed a reduction from 19.7 kWhr/m2/annum to 7.5 kWhr/m2/annum, a reduction of approximately 62%. BMS System Controls & Sensing: The large scale of the DEA Building and the contractual obligation to run the building for a period of 25 years require that a robust data monitoring, trending and analysis system be put in place. The BMS system selected is based on the open source KNX protocol allowing a multi-vendor supply of components over the life of the project and enhancing the long term maintenance adaptability of the system. The value of measurement of resource consumption is well documented and serves as the yardstick against which future improvement and design performance is measured. Bauer, Mosle and Schwartz (2010) highlight the importance of data collection that allows true interrogation of the long term rather than a narrow comparative year-on-year assessment. The BMS provided a platform that included raw data logging, trend and seasonal banding, variance and condition monitoring, historical records over the life of the building and detailed web based management and enquiry. The benefits of long term building performance data allow for the informed re-commissioning and optimisation over the life of the project thereby maximising the value of capital equipment and reducing operational impacts not only financially, but in terms of resources, including both energy and materials. The value of historical data in the optimisation of building performance is well documented and the results clearly point to improved outcomes based on the level of detail of historical data available. The BMS system has both control and monitoring functionality with adaptive optimisation capabilities. An area that is often overlooked when evaluating historical performance data is the prevalent weather conditions at the time of the event. The project has provided a high quality weather station that feeds a number of analogue and digital signals to the BMS regarding real-time weather conditions; the collected data includes rainfall, wind speed / direction, temperature and humidity as well as solar radiation, cloud cover and a number of additional metrics. Each of these measurements has a specific energy or performance impact on the building and provides invaluable context to the building performance data. Night Flush Ventilation: Weather data acquired from nearby meteorological sources provided an indication of the applicability of thermal mass utilisation based on assisting the HVAC system by reducing morning cooling loads with negatively impacting thermal comfort. The ability to utilise the thermal mass of the concrete structure of the building to store the rapid heat gains typical in an office area and limit the energy requirement of the mechanical cooling system was extensively modelled based on the availed Meteonorm data. Current research supported the consideration of a night â&#x20AC;&#x201C; flush principle and Clements-Croome (2003) notes that the inclusion of sufficient areas of exposed thermal mass affords designers the opportunity to improve thermal comfort in a commercial building environment. Generally accepted construction techniques typically isolate the inherent thermal mass of the building through the inclusion of ceilings, effectively eliminating a large potential passive heat store. In order to overcome this challenge the project provided a number of ceiling openings and perforations over 168

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the floor-plate that allowed the direct interaction of air from the occupied space with the exposed thermal mass of the high thermal mass concrete slab above. The slab effectively stores a portion of the heat, offsetting the peak energy demand for cooling and providing additional radiant comfort improvements.

Fig. 6: The impact of the night flush cooling strategy on indoor temperature over a 24 hour period Image: Solid Green

Venting of the area between the soffit and the partial ceiling allowed cool air drawn in through the automated window system to create a natural convective stack within the atrium, thereby removing heat from the soffits overnight in preparation for the following day. Fig. 6 indicates the impact of the design strategy on temperature differential attained through the application of night flush while Figure 7a and b provide a simplified overview of the conceptual design.

Fig. 7a: Evacuation of hot air through the atrium using an actuated faรงade night-flush protocol Image: PD Naidoo & Associates Consulting Engineers

Fig. 7b: Interaction of slab soffit and warm air allowing storage of heat within the thermal mass Image: PD Naidoo & Associates Consulting Engineers

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Renewable Energy Systems

The DEA project has incorporated one of the largest roof top mounted PV systems in South Africa on a commercial office building. The original Request for Proposal from the DEA stipulated that at least 10% of the building energy was to be produced on-site from a renewable source. The DEA building utilises both high efficiency solar-thermal systems for hot water, and photovoltaic for direct electrical energy production. Gaiddon, Kaan and Munro (2009) indicated that codes for â&#x20AC;&#x153;green buildingsâ&#x20AC;?, such as the South African Green Star SA Tool, provide a motivation for the inclusion of PV systems in the absence of compulsory PV specific building regulations and rewarded these system inclusions within the voluntary rating tool. The selected photovoltaic system utilises a direct feed into the building without a battery store and is utilised as generated. The described scenario posed some challenges in ensuring that the building base load was able to absorb the power generated on weekends and public holidays. The current design is based on high efficiency mono-crystalline fixed tilt roof mounted photovoltaic panels with a guaranteed lifespan equal to the operating contract of 25 years for the project. The selection of the installation angle was based on maximising the annual yield rather than seasonal output as well as adopting standard commercially available mounting system angles resulting in an installation angle of 25 degrees. The system was designed to be fully monitored and provide long term data collection to enhance the body of knowledge and promote solar PV as an energy technology, while providing a tangible reduction in energy usage over the life of the building. Figure 8 provides a three dimensional view of a portion of the roof mounted PV array.

Fig. 8: Dedicated roof area with solar PV arrangement on each block and wing of the building Image: PD Naidoo & Associates Consulting Engineers

Indoor Environment

Indoor Environmental Quality: The indoor environmental quality of a building is in all likelihood the most tangible interaction that the fabric of the building has with the occupant and has a direct impact on the end user experience of the space. Rostron, (2005) described a number of key building issues typically associated with indoor 170

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environmental quality, including lighting, ventilation, the presence of VOCâ&#x20AC;&#x2122;s, allergens and mould . The South African Green Star SA suite of tools provided the framework for intervention opportunities as part of the building rating process to ensure a conducive, healthy work environment. The DEA project design team has developed the interior strategy in a manner that minimises occupant exposure to harmful chemicals and constituents while enhancing the perceived health and comfort levels of the occupied spaces. Figure 9 provides a rendered impression of the interior elements contributing to overall occupant health and comfort. The project has specifically excluded volatile organic compounds in the specification of paints, adhesives and carpeting as well as a reduction in the presence of formaldehyde. The impact of poor lighting â&#x20AC;&#x153;flickerâ&#x20AC;? has been addressed through the inclusion of high frequency electronic ballasts to reduce eye strain while maintaining optimal lighting levels at low energy consumption. Comfort has been addressed through the inclusion of high performance double glazing improving the thermal performance of the space as well as providing significant improvement in the indoor noise levels and acoustic disruption. The selected double glazing system is comprised of a dual pane glass assembly with a performance outer layer and clear inner layer, bonded with an elastomeric polymer and desiccant spacer. The inclusion of Argon or Xenon within the cavity was found to be uneconomical relative to the performance gains achieved, again highlighting the need for the commercial optimization of proposed building systems to the intended purpose.

Fig. 9: Efficiently lit low emissions interiors provide the platform for enhanced occupant health and comfort Image: Boogertman + Partners Architects (Pretoria)

Innovation Showcase

Concentrated Photovoltaic (CPV) Vehicle Charging: The DEA has provided the project with the opportunity to showcase an advanced Concentrated Photovoltaic based electric car charging system. The CPV system is based on leading global concentrated photovoltaic technology that uses multiple Fresnel lenses to focus a beam of sunlight onto a small section of silicone at up to 500 times The green building handbook

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the original intensity (Soitec, 2011), the benefits of CPV technology are higher energy yields and the use of substantially less silicone than found in typical crystalline based PV panels, thus having an effective dematerialisation effect compared to traditional PV technologies. Based on the high CO2 emissions associated with the generation of coal based power in South Africa (Letete, Guma and Marquard, n.d.) an alternative source of electric car charging is required, providing and ideal fit with CPV technology. Research by Annair and Mahmassani, (2012) clearly demonstrates the emissions implications of coal-based electricity versus that generated from solar, a relevant consideration for South Africa. The site specific proposal for the DEA building included a tracking solar array and battery storage unit provided with an internationally standardised charge point and plug arrangement for the simultaneous charging of two vehicles. Design Integration & Building Information Modelling (BIM) A key imperative for the design and construction of the DEA project was to ensure that performance was optimised and any potential waste was minimised while ensuring all opportunities to maximise the building performance were explored. The entire project team across all disciplines adopted the Autodesk REVIT platform as the basis for undertaking the design as a building information model (BIM) rather than a collection of independent 2D drawings. While the adoption of the BIM concept and associated workflow required significant investment in time and human capital as identified by Kymmel (2008), the process presented an opportunity to realign with global trends. The project team reaped the benefits that began to emerge and this painted a clear picture of progress and the validity of BIM as an appropriate tool in support of sustainable design, including: • Visual Clash detection of services in 3D • Improved interdisciplinary coordination of services and structure • Integrated scheduling and measurement • Reduction in potential rework during construction and associated waste reduction • Energy and climatically sensitive environmental modelling Krygiel and Nies (2008) identified the benefits of the BIM approach from conceptual design massing through to the complex thermal, solar and energy modelling. The project has followed this path to enable the building to react appropriately to the climatic region and provide a platform for further optimisation through the appropriate building systems. The BIM process has provided a visual platform to optimise the building structure, fabric and services in such a way that material wastage and the inherent environmental impacts of this wastage have to date been limited, as well as recorded in a visually accessible three dimensional communication medium furthering the integrated design approach. Figure 10 clearly demonstrates the degree of integration available through visual review of the discipline specific design elements. As the building is a public private partnership and will be operated by the development consortium for a period of 25 years the BIM benefits have provided the ability, on completion of construction, to hand over to the operator a fully documented 3D model and database of the building to assist with the optimal management and lifecycle cost optimisation of the building over time. With the operational energy and environmental impacts associated with commercial buildings the long term environmental benefits of the initial investment are projected to be substantial. 172

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Fig. 10. The integration and coordination of multi-disciplinary services as a function of the BIM environment allows for optimal service placement Image: PD Naidoo & Associates Consulting Engineers≈

Conclusion The project provides an ideal showcase to South Africa of the significant contribution that the built environment can make in reducing the negative impact of continued development. The project further highlights the paradigm shift required in the manner in which design teams collaborate, integrate, iterate and innovate to deliver sustainable solutions and provides a tangible reference for transformation across both the private and public sector. References Annair. D & Mahmassani. A, 2012, State of CHARGE - Electric Vehicles’ Global Warming Emissions and Fuel-Cost Savings across the United States, UCS: Cambridge MA Bauer, M., Mosle. P. and Schwarz, M. 2010, Green Building: Guidebook for Sustainable Architecture. Berlin: Springer-Verlag Clements-Croome, D., 2003, Naturally Ventilated Buildings – Buildings for the Senses, Economy and Society. London: E & FN Spon Conradie, DCU and Kumirai, T. The creation of a South African climate map for the quantification of appropriate passive design responses. 4th CIB International Conference on Smart and Sustainable Built Environments, Sao Paulo, Brazil, 28-29 June 2012 DiLouie, C., 2005, Advanced Lighting Controls: Energy savings, Productivity, Technology and Applications. Lilburn,GA: The Fairmont Press, Inc. Gaiddon, B., Kaan, H. and Munro, D., 2009, Photovoltaics in the Urban Environment – Lessons Learnt from Large-Scale Projects. London: Earthscan The green building handbook

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Horn, A., 2009. The Life & Death of Urban Growth Management in the Gauteng Province. Pretoria: University of Pretoria Krygiel, E. and Nies, B., 2008, Green BIM: Successful Sustainable Design with Building Information Modelling. Indianapolis: Wiley Publishing Inc. Kymmel, W.,2008, Building Information Modelling â&#x20AC;&#x201C; Planning and Managing Construction Projects with 4D CAD and Simulations. New York: McGraw-Hill Larsson, N. and Poel, B., 2002. Solar Low Energy Buildings and the Integrated Design Process â&#x20AC;&#x201C; An Introduction. Cedar, MI: International Energy Agency Solar Heating & Cooling Programme. Letete. T., Guma, M. and Marquard, A., n.d., Information on climate change in South Africa: Greenhouse gas emissions and mitigation options. Cape Town : UCT Energy Research Centre Phillips, D., 2004, Daylighting: Natural Light in Architecture. Oxford: Architectural Press Rostron, J., 2005, Sick Building Syndrome Concepts, Issues and Practice. London: E & FN Spon Soitec, 2011, Soitec CPV Technology Data Pack, Peabody, MA: Soitec The Bill of Rights of the Constitution of the Republic of South Africa. (1996). Government Gazette. (No. 17678).

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Fort Hare Institute of Technology

The Fort Hare Institute of Technology (FHIT) established itself as a hub within which state-of-theart expertise and infrastructure are housed to support the rest of University of Fort Hare, industry, commerce, neighboring institutions and local communities. The objective is to put in place a highly professional academic, organizational and competitive system that will provide academic, research and market opportunities, as well as support to its interns and postgraduate students, to enable them to contribute and compete meaningfully to the global economy, global knowledge society and in the information age. The education and training in science and technology and technical skills are customized to the needs of industry and local communities. A multidisciplinary pedagogical approach that stimulates the integration of fundamental applied sciences, design methodology, social sciences, and law and economics is adopted. FHIT, under the directorship of Professor Edson L. Meyer, established education, training, research and development around five key research niche areas; namely, Solar Energy, Biomass Energy, Energy Efficiency, Energy Resource and Environmental Assessment, and Energy Policy. To achieve its strategic priorities and goals, FHIT utilizes advanced material science, computer modeling and smart metering as enablers. Professional expertise in the five research niche areas enables staff to provide consulting services to industry and government on energy and related matters.

Contact details: Prof Edson Meyer Tel: +27 40 602 2311 Email: emeyer@ufh.ac.za

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Biomass Energy Research

http://fhit.ufh.ac.za

Being situated in the rural Eastern Cape, research on biomass energy proved invaluable to the surrounding community at large. FHIT has been instrumental in setting up the first commercial biomass gasifier plant at the nearby Melani village. This improved the standard of living of the otherwise impoverished rural community. For this project, the waste from the sawmill at the village is used as a fuel for biomass gasification, producing more than sufficient electricity to power a containerized bakery run by the community. Therefore, essentially turning wood waste into bread. Research around this focus area include the improvement of the collection efficiency of the gasifier cyclone, thermal and chemical analysis of the gasification process and associated feedstock, combined heat and power generation (CHP), and co-gasification of biomass and coal in high temperature gasification. Recently, sugarcane bagasse has also enjoyed some attention as a fuel for biomass gasification. On campus, FHIT has an experimental biomass gasifier for determining material characteristics and heating values of various biomass materials. In addition, FHIT in collaboration with the physics department is now conducting research on anaerobic biogas digesters at the SOLAR WATT PARK. A number of business opportunities and postgraduate research projects are available. For more information contact the niche leader and senior researcher, Dr. Mamphweli: smamphweli@ufh.ac.za FHIT conducts research in solar cells, solar modules and systems, and solar thermal. Recently, a hybrid photovoltaic (PV) and photochemical (PC) cell structure was designed and fabricated using 176

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Solar Energy Research

http://fhit.ufh.ac.za

ultrasonic spray pyrolysis and carbon doping. In addition, a hybrid PV thermal system has been developed and is now in the prototype phase. Research on the degradation and failure of PV and PC solar cells, modules and systems entails optical characterization, electrical characterization and structural analysis. Building integrated photovoltaics is one of our niche areas and targets both existing and new buildings and is aimed at addressing a wide spectrum from low-income dwellings to commercial buildings. On campus, FHIT has three active PV systems in the kW range with grid connection capability. These three systems employ different PV technologies as well as different invertor technologies and, with passive solar design features and solar water heaters (SWH), render the buildings independent of the national utility. These facilities are then used to present handson renewable energy and energy efficient training courses for unemployed graduates, interns from private and public sectors as well as postgraduate research projects. The SOLAR WATT PARK also provides facilities for standardized testing on PV modules, SWH and heat pumps targeting industry with new products and entities initiating energy efficient device or process rollouts. A number of business opportunities and postgraduate research projects are available.

For more information contact the Director, Prof. Meyer: emeyer@ufh.ac.za

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Voidcon Decking Systems VOIDPRO MANUFACTURING (Pty) Ltd The company started supplying the Decking System in 2004. The products were manufactured by Safintra and March 2012, Voidpro Manufacturing took over the production process, and opened its own production facility. By utilising the Franchise business system, Voidpro Manufacturing ensured that it has presence throughout the country, in 8 of the 9 provinces plus Namibia and Botswana.

WHAT IS THE VOIDCON DECKING SYSTEM Voidcon is a composite suspended slab system, suitable for industrial, commercial and residential buildings. The system consists of galvanized steel profiles which are laid in position, into which concrete is poured. The concrete provides strength, while the steel provides stability. As a result, the system uses substantially less concrete than conventional decking systems and offers the client substantial cost saving. Because it uses less concrete and steel, it is substantially less harmful to the environment. VOIDCON DECKING SYSTEM FEATURES Voidcon steel decking system has 3 outstanding features: • Permanent Decking – Provides a simple interlocking deck to support mass wet concrete and other construction loads. • Composite Action – Not only acts as permanent shuttering but serves as tensile reinforcement, resulting in a composite action with the concrete.T-Beam System • The profile design is base on a T-Beam system that provides beams and voids for large reduction in in-situ concrete volumes. BENEFITS OF THE VOIDCON DECKING SYSTEMS • 40% - 60% Concrete saving Lightweight system Minimal propping requirement Saving on cranes 178

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PROFILE Highly cost-effective • Exceptional strength due to the T-Beam design Composite action of the system leads to an extremely strong bond between steel and concrete. • National and International representation leading to Comprehensive technical support Voidcon’s business model utilises the franchise system, with presence in all the provinces (except Gauteng) Franchises in Namibia and Botswana Gauteng serviced directly by Voidcon • Product versatility Ideal for complicated shaped slabs Ample space in voids for all services (Electrical & Plumbing) • Improved sound and temperature insulation • Easy installation of conventional ceiling systems

CONCLUSION Voidcon decking systems is a proudly South African product, designed and manufactured in South Africa. The name was appropriately chosen because the system offers a decking system that has – Voids in Concrete! The system can be viewed as a complete package with variable cost savings in areas like concrete, cranes not needed, minimal support compared to conventional slabs and therefore contributes positively to meeting delivery deadlines. In terms of transportation, the lightweight materials can be moved in large quantities with minimal effort. It is thus a fair assumption to state that the steel to concrete ratio used, puts the product squarely in the Eco Friendly Products’ category. CONTACT INFORMATION Phone: 086 110 6275 Fax: 086 637 6176 Email: info@voidcon.co.za Mobile: 072 411 7449 Website: www.voidcon.co.za The green building handbook

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DetNet South Africa (Pty) Ltd Energy Efficient Building Riaan van Wyk Chief Technical Officer DetNet South Africa

Introduction

From a designing perspective, a green building can be energy efficient by implementing technology systems as well as natural and architectural systems to reduce energy consumption. There are many ways to be energy efficient, but the strategies may not always be considerate to the environment. Green design favours nature conservation and minimizes carbon footprints, whereas energy efficiency reduces the cost of energy which also concludes in a smaller carbon footprint but may make use of less environmentally friendly materials. DetNetâ&#x20AC;&#x2122;s decision to go for energy efficiency as first priority before going purely green will be discussed in more detail.

Background of DetNet

DetNet is a joint venture company between two explosive suppliers, Dyno Nobel and JSE listed AECI. Its business is to focus on designing and manufacturing electronic detonators and its associated control equipment. All control equipment is manufactured on the premises. DetNet originally shared premises with AEL, a sister company which provided the company infrastructure. DetNet was required to move to new premises and a decision needed to be made regarding the building type i.e. Standard, Efficient or Green. For DetNet, saving energy is important as well as being green. A few critical decisions had to be made such as the type of air-conditioning system and type of Building Management System (BMS). One of the key factors for deciding on the type of building and systems was the return on investment. After initial research, the return on investment did not justify a fully green building because it is difficult to comply with all the aspects of the green check list. However sustainability was important to DetNet and therefore only green aspects with a return on investment within 5 years were considered. With the rising electricity costs in South Africa and the potential cost saving with an energy efficient building, the board considered an additional expense of R1.4m for energy efficiency as a sound investment.

Electricity Usage

The estimated electricity usage in DetNetâ&#x20AC;&#x2122;s Office building with a fully air-conditioned workspace can be represented in Figure 1. The highest usage of electricity is from the air-conditioning system, followed by the IT system, lighting and water heating. DetNetâ&#x20AC;&#x2122;s IT requirements are much higher than most other companies, where you would typically expect lighting power consumption to be higher than the IT system consumption. This graph should be kept in mind when deciding on infrastructure equipment and management techniques. From figure 1 it became clear to focus on minimizing energy usage of air-conditioning, IT and lighting systems. The majority of the energy efficient budget was directed into managing these high energy usage areas.

Architectural Design

The fundamentals of any Green or Energy Efficient Building are with the initial architectural designs. All the energy efficient design aspects of the building combine to form a final efficient system. DetNet Architectural requirement was modern, high-tech, different and the external facade should mainly be white with clean lines. The green building handbook

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From a technical point of view, all external walls contain a cavity of 40mm between the external brick and internal brick layers. The roof slabs are isolated with 40mm extruded polystyrene with an R-value (Thermal resistivity) of 5 to isolate the roof slab to the interior of the building. Extruded polystyrene for the roof slab was the one area where efficiency and availability of product took priority over purely green materials. In addition to this, the roof is painted with reflective silver sealant to reflect direct sunlight from the roof and not to absorb the heat. Double glazed windows are installed on the outside, western side of the building and thermal reflective glass on the Northern side of the building. All aluminium window frames consist of rubber seals to ensure an airtight fit. Sunshields are installed on the northern and western side of the building and are aligned to protect the windows form direct sunlight at the warmest time of the day in summer. Figure 2 : Sunshields on Northern side

On the green side, DetNet thought about low solvent paints and bio degradable materials. DetNet did not insist on this, The green building handbook

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but low solvent paints were used in the end. The building material was selected to be durable and to conserve energy input in the building. In the end DetNet’s main goal was efficiency and not necessarily green.

Mechanical Engineering

Today mechanical engineers still design heating and cooling system at “500 – 600 BTU/m2”. DetNet’s Mechanical engineers followed this design principle when they designed the air-conditioning system of the building, although it was stated in the initial design the insulation material will be used as well as cavities in the walls. The result concluded that the air-conditioning system for the building was completely over designed at the time of construction.

Building Management Systems

A Building Management System (BMS) is a computer-based control system installed in buildings that controls and monitors the building’s mechanical and electrical equipment. The BMS is designed to take control of the heating, ventilation and air-conditioning (HVAC), illumination, water systems, security systems and any other electrical equipment such as blinds, projector screens and electrical appliances. These Building Management Systems can be expensive but after initial calculations, it was proved that a system would indicate a return on investment in less than 3 years. Efficiency is to achieve maximum productivity with minimum wasted effort or expense. To be efficient, DetNet required a BMS to manage electricity efficiently. DetNet insisted on a BMS that supports an open standard to ensure easy connectivity to other systems. An open system architecture will assure that the building will not be locked in with only one supplier or system and this reduces complications of future expansion. The BMS is also required to have minimal maintenance and configuration requirement from the occupants and should be user-friendly to work with. Heating and cooling consumes most of the electricity to provide a comfortable working environment, followed by IT and Illumination systems. To achieve maximum efficiency of electricity use, the high usage areas such of these are managed as thoroughly as possible. Other electrical devices such as the water heaters, water coolers and coffee machines are also managed by the BMS to provide an additional electricity saving. DetNet decided to build their BMS on the KNX Platform due to the local availability of the components and the open standard they provide.

Working Environment Temperature

Thermal comfort can range between 18⁰C and 26⁰C depending on factors such as air movement and humidity and as Figure 1 illustrated, the HVAC (heating, ventilation and air-conditioning) system uses the highest percentage of total electricity, it should be noted that the biggest cost can be saved by managing the HVAC correctly and installing the most efficient system. DetNet installed an inverter air-conditioned system to provide the building with heating or cooling of workspace environment. An inverter air-conditioner controls the speed of the compressor motor to allow continuously regulated temperature where the traditional air-conditioner’s compressor is either running at maximum power or off. Inverter systems not only improves the efficiency of the heating or cooling system but it also allows the temperature to be controlled more precisely without a major change in air temperature between compressor switching times. 184

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DetNet opted to install smaller air-conditioner units into areas of the building rather than one global air-conditioner. This allows occupied areas to be controlled and unoccupied areas to be turned off. DetNet calculated and tested that the best relationship between efficiency and thermal comfort is to cool the building down to 23⁰C when cooling is required, and heat up the building to 21⁰C when heating is required depending on the exterior temperature acquired by the weather station located on top of the building. Another design aspect of the system is to continuously measure all the unoccupied areas inside the building and heat up the building, if the temperature drops below 16⁰C and cools down if the temperature reaches above 28⁰C. This control is implemented to keep any equipment and plants inside the building from temperature damage. All the measurements and temperature controlling are done with the BMS system. The BMS system is configured in two general modes namely normal and afterhours operating modes. Normal mode includes turning on all air-conditioning systems in the work areas during normal working hours. In after-hour-mode only occupied areas temperature is controlled by the air-conditioning system. DetNet is located in a low lying area and this cause the temperatures to drop in winter to close to -5⁰C thus the fresh air ventilation is controlled via the BMS system to minimize the required energy input to get the fresh air to a working environmental temperature. The ventilation is managed to ventilate the building on a conditional basis. Conditioning is done by logic decisions. As illustrated in Table 1, ventilation occurs for 45 min when the outside temperature is within 2⁰C of the inside temperature set point. However this does not always ventilate the building during the extremely cold and hot days. To improve on this the building will always ventilate for 80 minutes during the hottest time of the day when the outside temperature is less than the internal temperature set point, this is typically at 14:00 in winter. To ventilate during hot periods the building will always ventilate for 80 minutes at 07:00 if the outside temperature is above 17⁰C. This also assists in cooling the building down after a heat build-up during the night from any equipment. If this system is not running as such, an additional 6.2 W/m2, (39% power consumption increase) is noted during cold winter or warm summer days.

Working Environment Illumination

DetNet achieved the correct illumination levels efficiently by installing T5 high efficiency fluorescent tubes throughout the building. These fluorescent lights have a high power factor and use hot start ballasts instead of a starter (coil) to switch them. They are controlled via a presence sensor which is connected to the BMS system, this ensures that only occupied areas are lid. 230VAC LED down lights with high power factor built-in regulators is used in areas to emphasise architectural details. To enrich the interior lumens of the building, highly reflective surfaces such as white desktops and reflective cream marble tiles are used with as much natural light as possible from an architectural perspective. The centre foyer lighting is controlled by the BMS system on account of the outside lumens as provided by the weather station, there are 3 chandeliers which turn on in two sections as the outside lumens drop. First the stairway chandelier followed by the mid foyer chandeliers at different lux levels. All external lights are controlled by the BMS system. The rest of the exterior illumination was carried out by placing LED strip lights in close proximity to the architectural features of the building. A mixture of warm and cold temperature coloured white LED lights was used to accent certain building features. Most walkways and parking bay lights are switched off after 23:00 if there is no presence inside the building for more than an hour. The green building handbook

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DPI Plastics highlights the importance of ‘Best Practice’ PVC products

Environmentally conscious building contractors and architects can benefit from making use of PVC piping products produced by companies that are recognised by the Southern African Vinyls Association (SAVA) as ‘Best Practice PVC Manufacturers’. DPI Plastics is a leading manufacturer of water reticulation, drainage and pipe fitting systems in South Africa, and in January 2012 became recognised by SAVA as a Best Practice PVC Manufacturer after officially becoming a signatory of the association’s Product Stewardship Programme (PSP), which is a series of achievable commitments to address the industry’s environmental issues. “The GBCSA announced that the use of PVC products in sustainable projects will no longer be penalised, by recently removing the MAT-7 PVC minimisation clause from its green star tool rating system. The removal of the clause means that environmentally conscious contractors can enjoy the benefits of PVC products, while ensuring that they have a neutral impact on their GBCSA green star rating,” notes DPI Plastics technical manager, Renier Snyman. As a SAVA PSP signatory, DPI Plastics has committed itself to following fundamental key aspects of the manufacture of PVC piping products including but not limited to (1) Responsible and sustainable use of additives; (2) Responsible and sustainable vinyl recycling programmes; and (3) Effective communication to all stakeholders regarding industry progress. DPI Plastics is also playing a major role together with its Southern African Plastic Pipe Manufacturer’s Association (SAPPMA) partners in entirely eliminating lead from all locally manufactured plastic pipes. Although lead creates no immediate risk to the end-user, it does pose a serious risk during the manufacturing process, as raw lead comes in powder form and creates a toxic dust that can be inhaled and absorbed into the skin by factory workers and suppliers of the lead stabilisers. DPI Plastics and other SAPPMA members decided to remove lead from the manufacturing process on an entirely voluntary basis, as part of their ongoing commitment to corporate, social and environmental responsibility. For further information kindly contact Renier Snyman, Technical Manager, DPI Plastics. Tel: 011 345 5600 E-mail: rsnyman@dpiplastics.co.za or info@dpiplastics.co.za Visit: www.dpiplastics.co.za 188

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Compact fluorescents need to be priced competitively to replace filament light bulbs, thus the designers use cheap and inefficient circuitry, due to this extreme power factor inefficiency and shortened lifespan if housed in enclosed light fittings, compact fluorescents with built in electronics were banned from using as illumination equipment. Only one standard high powered flood light is used for external lighting due to high power usage.

Water conservation and Water heating

DetNetâ&#x20AC;&#x2122;s attempt to include green features to their efficient building took water into consideration. DetNetâ&#x20AC;&#x2122;s consideration was water handling. Due to the nature of the business most of the waste

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Rickard Air Diffusion Rickard Air Diffusions slogan “Intelligent Comfort Control” underlies its belief that VAV Diffusers must be designed to not only intelligently maintain comfort levels but achieve this efficiently too. South Africa is unique in that it uses Variable Air Volume diffusers in the majority of its buildings that are air-conditioned with ducted systems. The alternative commonly used overseas is a combination of constant volume diffusers and VAV boxes. The advantage of VAV diffusers are their energy savings, comfort levels and flexibility. A study by an external engineering consultancy shows that VAV diffusers save 20% of an installations air-conditioning energy expenditure and 5% of the entire buildings energy bill. Unlike VAV boxes, VAV diffusers directly affect fan speed and hence energy used when they reduce the volume of air into the conditioned space. VAV diffusers are also able to maintain air movement and comfort levels while doing so. Rickard uses industry leading controls to intelligently control its products and the latest Engineering tools to design them. They offer the client seamless integration into a buildings management system and unparalleled flexibility for building layout changes. Rickard offers further energy saving functionality through built in occupancy sensing that closes the diffuser when the room is unoccupied and airflow sensing that saves commissioning cost and calculates a zones energy use. The advantages of VAV diffusers and Rickards focus on innovation and quality has seen growth for the company into overseas markets. Rickard sees further potential in smaller buildings where energy saving is a deciding factor.

Contact Details Cape Town: 021 704 1533 (Head Office) • Gauteng: 012 804 5488 • Eastern Cape Agent: 041 487 1781 KwaZulu Natal Agent 074 169 6168 • sales@rickardair.com • www.rickardair.com 190

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water is classified as black water. This minimised the effect that DetNet could have on waste water management. The only area left where DetNet could bring their contribution to water saving is controlling the amount of water it uses. When it came to the design of DetNetâ&#x20AC;&#x2122;s watering system, it was decided to directly couple coffee machines with ceramic filters and not reverse osmosis filters as it is inefficient and uses a lot of water. Automated taps in the bathroom area include aerators to reduce the volume of water which pours out of the taps, as well as low volume auto flush urinals and dual flush toilets. Under counter geysers are installed to ensure immediate availability of hot water to the basins. This reduces the time, water and energy wasted to transport warm water from a communal geyser to each warm water tap. Water saving in the garden included indigenous planting. The plants require minimal water and a minimum use of lawn with an irrigation system which receives irrigation commands from the BMS. The BMS system can command the irrigation system not to irrigate the plants if it had rained in the past 24 hours and an irrigation cycle is imminent.

Appliance Controlling

DetNet implemented the following schedule as set out in the table below in the control Logic of the BMS. The following appliance / electronic devices are controlled with respect to energy efficiency as well as safety considerations were kept in min

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Beyond Engineering The Graduate School of Technology Management (GSTM), University of Pretoria, is the first graduate school of its kind in South Africa. The GSTM provides skills solutions in Engineering Management, Technology Management, Innovation Management and Project Management to practising engineers and scientists, with the option of domain specialisation to allow for meaningful expansion of the programmes. Degree programmes: Masters in Engineering Management (MEM) Masters in Project Management (MPM) Masters in Technology Management (MTM) Honours in Technology Management (MOT)

For more information on programmes offered by the GSTM, visit www.up.ac.za/gstm

Year programmes and short courses:

mediachef4903

Project Management Engineering Management Technology Management Maintenance Management Logistics System Engineering

Universiteit van Pretoria • University of Pretoria • Yunibesithi ya Pretoria Privaatsak • Private Bag • Mokotla wa Poso X20 Hatfield 0028 • Suid-Afrika • South Africa • Afrika Borwa Tel: +27 (0) 12 420 4111 • Fax • Fekse: +27 (0) 12 420 4555

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Building Monitoring

The BMS system main function is to control services efficiently but itâ&#x20AC;&#x2122;s not the only feature it provides for the Building. DetNetâ&#x20AC;&#x2122;s BMS is set up to display instantaneous results such as Total Power Usage, Highest Instantaneous Power Usage, Outside Temperature, Lux levels and wind speed can be displayed. DetNet also set up their boardroom touch panels to inform employees of any error which the BMS measures, this can be errors such as Generator Fuel Level Low or UPS Battery Errors.

Electricity Saving IT - Systems

DetNet was also required to host their own line of IT infrastructure which includes backend servers, user desktops, network switchgear and telephone system. Due to nature of the business DetNet requires a sophisticated IT infrastructure which includes 560 network points for 90 people and 10 server platforms. All services run over Ethernet including, Security cameras, IP Telephones, selected building control systems and automated production testing equipment and test jigs. To minimise the electrical cost of the backend servers, the 10 required servers were virtualised to 5 Physical machines.

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Another concept was to distribute lower power desktops (Thin clients) to employees and services which donâ&#x20AC;&#x2122;t require a fast processing environment. With this action taken DetNet reduced an average power usage from 300W to 30W per workstation for general office workers. Not only was there a saving on electricity but these machines do not require a lot of desk space. Additionally all CRT monitors were replaced with LCD flat panels, preferably with LED backlights which saved an extra average of 75W per workstation. After this efficiency drive, DetNet reduced their IT related energy usage by nearly 300 Kwh/day which was a reduction of 60% on the IT power consumption. The IT system uses an average of 7.9 kW afterhours, (3.6 W/m2) and an average of 8.9 kW during working hours (4.0 W/m2).

Conclusion

To conclude, DetNet have reduced their power bill with more than a half. DetNet currently has an electricity usage per square meter with an average of 19.5 W/m2 during day mode. The final measurement after a year resulted in an average usage of 15.0 W/m2 for the year of Jul 2011 to Jun 2012. The extreme months had an average of 16.3 W/m2 in winter (Jun-Aug) and 16.1 W/m2 in summer (Dec-March). This achievement was made with standard, readily available technology at the time of implementation. With our original planned power density of 80 W/m2, solar voltaic cells to power the building during daytime was considered but was found too expensive. With a 15 W/m2 requirement solar power becomes cost effective and very viable. Something we will consider doing in the future.

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LYT Architecture

LYT Architecture began life as Tyser Pellegrini some 25 years ago as a small mining focused architectural practice and through several iterations, most recently as TPS.P Architects, has become one of the largest and most successful practices in the country. In September 2012, the practice was re-launched as LYT Architecture, a brand which reflects not only a new management structure and style, but also a focus which builds on the successes and expertise of the past and which looks to the future as a pro-active wealth creating enterprise seeking to address many of the pressing issues in South Africa through a design orientated solutions driven approach. While maintaining its position as a leading commercial practice, LYT remains the most diversified design and architectural practice in South Africa with significant skill and experience in the design and delivery of mining, infrastructure, industrial, educational, residential, commercial, hospitality, retail and transportation projects, both in SA and abroad. Notwithstanding the tough economic circumstances in 2013, the practice looks forward to an exciting year with several large commercial and retail projects in the ground as well as a promising list of imminent new work across the full spectrum of its operations and services. Key to LYT’s success has been its ability to maintain and grow strong relationships with its client base and its “can-do” approach. LYT’s current projects: New building for TWP (Green Star Rating) Head Office for Group 5 for Atterbury (Green Star Rating) Unilever Production Buildings (LEED Certification) Maretlwane Outdoor School, the first Green Star Educational Building Contact Details Tel: 011 218 3710 2nd Floor, No3 Melrose Square, Melrose Arch, Johannesburg www.LYT.co.za The green building handbook

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GREEN SCHOOLS SYSTEM by LYT Architecture

‘Greener schools for a smarter future’ ADDRESSING SOUTH AFRICA’S EDUCATION INFRASTRUCTURE PROBLEMS THROUGH QUALITY DESIGN, APPROPRIATE TECHNOLOGY AND FOCUSED DELIVERY.

We in South Africa are facing a nationwide education crisis exacerbated by the paucity of adequate facilities, educators and materials and a seeming inability by Government to reverse the downward trend. As much as its policies and intentions are well founded and stand scrutiny, it is at the level of implementation and delivery that South Africa is falling short. As the schooling budget backlog escalates into the billions and tens of billions of Rand’s with each passing year, Government is confronted with myriad contradictory proposals, which are being implemented on an ad-hoc basis. Often the impetus for projects is driven by shortterm politically motivated agendas. As a result, the quality of school infrastructure is inconsistent and the approach to delivery is often based on expediency rather than from a considered strategy. LYT as a design practice operates in the built environment space and has approached education by creating a vision for rural and suburban schools which we believe has the ability to transform the way that government will think about its infrastructure roll out while creating opportunities for entrepeneurs and local communities at the same time. It is a fundamental tenet of our philosophy that even the most remote rural community has a right to have its children educated in an appropriate, sheltered, sustainable and safe environment. We had to design a rural school system that could be rolled out across the country, with these as key requirements: • A design that conforms in every detail to the requirements of the Department of Basic 196

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PROFILE Education requirements for schools and is adaptable to cater for all varying permutations with respect to size, school level and ancilliary facilities. • A modularised design system that’s adaptable to a number of different sites and climates • An alternate technology system that includes a roof that is self-supporting and frees up the area below, to allow walls to be built independently • Quick construction time • Economically and environmentally sustainable • Community involvement and ownership • High flexibility of spaces and overall design • Durability, strength and ease of maintenance Sustainability and Green Strategies Our overriding approach was to use green strategies in a playful and ergonomically efficient manner, so that the pupils see these features as a delight. Elements like solar power and wind driven stacks, water storage tanks and wind turbines become a defining feature of the architecture. The green elements serve multiple overlapping functions maximizing value for money, simplicity and robustness where appropriate. Each element is part of a system where the whole is greater than the sum of its parts. Given the urgency of the demand for new schools in South Africa it is entirely appropriate to consider new alternate building technologies that lend themselves to improved economy, speed of delivery and performance relative to traditional building methods. The new school concept can thus be thought about as a potentially mass-produced yet customizable system unique to us.

Contact Details Tel: 011 218 3710 2nd Floor, No3 Melrose Square, Melrose Arch, Johannesburg www.LYT.co.za The green building handbook

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COROBRIK PREFACE This profile presents the case for Corobrik bricks in providing sustainable more energy efficient buildings with low total greenhouse gas emissions over a 50 year lifecycle.

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.

Reducing Corobrik’s Emissions 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 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. Corobrik presently has two CDM projects registered with UNFCCC.

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 14001 Environmental Management System Certification

Corobrik has SANS 14001 Certification at four SANS 9001:2008 certificated factories and is pursuing a programme to extend certification to all Corobrik factories.

EMBODIED ENERGY OF COROBRIK MASONRY MATERIALS AS WALLING SYSTEMS The Carbon Footprint of Corobrik bricks

As calculated by CSIR Built Environment, the embodied energy of bricks from 3 typical technologies Corobrik employs, ranges between 23.2 and 33.8 Kg CO₂/m² single skin of brickwork. Ideas and 198

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PROFILE interventions with the potential to effect incremental reductions in emissions are continually being assessed and implemented where appropriate.

Embodied Energy in Context

The full LCA by Energetics found that no matter the construction type the embodied energy of a house was less than 10% of the total energy [embodied plus operational] consumed by the house over a 50 year period. Hence while pursuing interventions to incrementally reduce the embodied energy of materials has relevance, focusing on operational energy component is where the biggest opportunity for greenhouse gas emission reductions exists.

CLAY BRICKS CONTRIBUTION TO THE ENERGY EFFICIENCY OF WALLING ENVELOPES Research estimates heating and cooling energy to comprise 25% to 40% of total energy consumed in houses here in South Africa. The findings of Energetics Australia’s full Life Cycle Assessment of five walling alternates in two house types located in three climatic zones and four orientations correlate with 8 years of empirical research, a parametric study and three significant thermal modeling studies in South Africa confirming thermal mass, naturally inherent in clay brick masonry, as a critical thermal performance property for optimizing thermal comfort and for achieving lowest energy usage for heating and cooling of houses located in climates typical of the 6 major climatic zones of South Africa.

Comparative Thermal Comfort

Thermal discomfort drives behaviour to achieve indoor 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. The higher the CR Product of a walling envelope the greater the correlation was found to be.

Findings of “A Study of the Thermal Performance of Australian Housing” [www.Thinkbrick.com.au for downloadable document]

This 8 years of empirical study to understand the role of clay masonry in achieving sustainable design, has proven clay brick is a superior building material in producing thermally comfortable, energy efficient environments, for people to live, work and play. As a case in point and as depicted in Figure 13 below, the insulated lightweight walled building (R1.51) with over three times the R-value of the cavity brick (R0.44) used over three times the energy to maintain the temperature in the comfort zone during the Spring period of 2007. This 8 years of research where heating and cooling requirements of four full scale test buildings comprising different wall construction types was measured using a total of 105 sensors and data recorded every 5 minutes for 24 hours per day found: • The lightweight building was the worst performing in all seasons • Brick veneer performs better than light weight • The insulated cavity brick performed the best • Thermal mass in floors alone is not sufficient to reduce extremes in temperature • There is no correlation between the R-value of a wall and energy usage • R-value is not the sole predictor of thermal performance The green building handbook

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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 superior energy efficiency with the best payback. The SANS 204 compliant 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 wailings’ superior thermal performance attributes was 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 for energy efficiency optimization. In this study the double brick un-insulated walled house outperformed the timber frame insulated weatherboard alternate in most situations while the insulated brick outperformed in all situations.

CR Product and SANS 204 Energy Standards for Masonry Buildings

The CR Product values as incorporated in SANS 204 Energy Standards for masonry buildings [presently voluntary] were found, in the WSP Green by Design 130m² house study, to provide for greater thermal comfort than the LSFB SANS 517 and 204 compliant house in all six major climatic zones. These CR Product values also represent minimum lifecycle cost options at the time the SANS 204 standards were proposed. The graph below depicts the comparative PMV amplitude ratios for different wall types in climatic zone 1. The poor performance of lightweight walling correlates with empirical and thermal modeling studies that used ASHRAE and Agrément SA accredited software.

COMPARATIVE LIFECYCLE CARBON FOOTPRINTS OF WALLING SYSTEMS Corobrik clay brick walled houses offer the propensity to amortize their embodied energy and achieve 200

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PROFILE a low total carbon footprint in the long term. Two studies that demonstrate that the savings in heating and cooling energy that clay brick construction affords translate into lower total [embodied plus operational] Greenhouse Gas emissions over a defined lifecycle include:

40 m² Low Cost House Study

Over a 40 year life cycle this desk top study found that two leaf brick accounted for a total 50.1 tons of CO2 [embodied plus operational] this 10.2 percent less than the SANS 204 compliant LSFB insulated lightweight walled alternate located in Johannesburg. Cavity brick and insulated cavity brick offered further improvements on this.

Energetics Full Lifecycle Assessment

This study established that the HVAC energy savings of the insulated clay brick house [R1.3] on average translated into 15.1% lower operational Greenhouse Gas [GHG] emissions over 50 years than the lightweight timber frame weatherboard alternate. This resulted in cavity brick affording lower total [embodied + operational] GHG emissions over timber frame in most situations and insulated brick in all situations..

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, 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 that are significantly environmentally friendly. For more information go: www.corobrik.co.za Email: intmktg@corobrik.co.za The green building handbook

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Building Thermal Loads: A case study for David Hellen Petta public secondary school

Tichaona Kumirai Researcher, Built Environment Unit CSIR

Introduction Statistics published by the Department of Basic Education in November 2010 reveal the following: 1. there are 11 834 516 learners that attend public schools: 2. there are 387 837 educators for public schools: and 3. there are 24 699 public schools in South Africa (DOE, 2010). These statistics show that almost 25% of the South African population spends the majority of its time in public school buildings. Often, however, indoor environmental conditions in the classroom are not conducive to learning. Gibbert et al, 2012, carried out measurements for air temperature in an occupied classroom at David Hellen Peta public secondary school. The measurements were done in an over-occupied classroom (45 learners) during winter and summer. The results of the measurements reviewed classroom temperatures above 30˚C during summer and winter temperatures below 18˚C. Both measured winter and summer temperatures are outside the thermal comfort band (20.5°C -26.5°C, calculated as shown in Figure 5) for the site (ASHRAE, 2004). Extreme thermal conditions have been found to increase irritability and reduce students’ attention span and mental efficiency. This results in an increased rate of student errors, increased teacher fatigue and deterioration in work patterns (Department of Basic Education, 2008).

Aim of research This chapter assesses the impact of appropriate passive interventions on building thermal loads. The passive interventions investigated are ceiling insulation, wall insulation, attic ventilation, natural ventilation and roof absorptance and their combinations.

Limitations of research 1. The thermal load reduction potential for the stated passive strategies was quantified by simulation only. 2. The research is limited to David Hellen Petta public school which is located in Atteridgeville, Pretoria West.

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A typical classroom in the middle of the block with two external walls exposed to the atmosphere at David Hellen Petta secondary school was used in the case study. The site is located in Pretoria west, Atteridgeville, South Africa (latitude 25˚46’45.84’’S, longitude 28˚04’12.16’’E, altitude 1443 m).

Figure 1: Southern facade (left) and Northern facade for DH Petta classroom block

Field studies The field studies were primarily done to acquire data for calibration of the Ecotect thermal model. The field studies were conducted from 13 June – 15 June 2012. One HOBO™ (air temperature and relative humidity measuring device) was suspended in the middle of the classroom at 1.1 m above finished floor level (Figure 2). The measurements were done in an un-occupied classroom. The other HOBO™ was suspended 6 meters above ground, in an open area outside the classroom. The measured air temperatures inside and outside classroom are shown in Figure 3.

Figure 2: Illustration for temperature and humidity measuring data logger suspended 1.1 m from finished floor level 204

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Figure 3: 13 June â&#x20AC;&#x201C; 15 June 2012 measured indoor and outdoor air temperatures with no occupancy and windows and doors closed.

Ecotect model All classrooms were considered as discrete thermal zones (Figure 4). The attic (ceiling void) was also considered as a separate thermal zone. This was done to account for inter-zonal thermal exchanges. The classroom used in the study is zone: E3 (blue coloured zone, see Figure 4 left). This zone corresponds to the classroom where field studies were carried out.

Figure 4: Ecotect Thermal model for classroom block, left. Illustration of the three sections of the wall, right. (see Figure 7).

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Inputs of the thermal model Weather file The Pretoria Irene weather file was selected for the simulations because: 1. Irene falls into the same Köppen Cwb (Highveld) region as DH Petta location (Pretoria, Atteridgeville) (Conradie, 2011). 2. The Irene weather data is based on actual recorded measurements which is prefered over the interpolated data generated with Meteonorm. In order to ensure that the simulation weather file and actual measured temperatures correspond closer to ensure better predictive simulation, on site outdoor temperature and relative humidity were recorded. These were then inserted into the Pretoria, Irene weather file. This was an attempt to get a closer correlation between observed and predicted values.

Human thermal comfort for naturally ventilated and air conditioned spaces ANSI / ASHRAE standard 55 - 2004 was used in determining thermal comfort bands (for both naturally ventilated and air conditioned space) for the case study site. For thermal comfort band (20.5°C -26.5°C, calculated as shown in Figure 5) for naturally ventilated space, 90% acceptability criteria was used given the importance of thermal comfort to learners. Climate Consultant V5.4 developed by UCLA energy design tools group was used to calculate the approximate winter average and summer average temperatures for Irene (Figure 5). The thermal comfort band (21°C - 24.5°C) for an ideally air conditioned classroom (Figure 6) was calculated using the following assumptions: 1. For the summer upper thermal comfort limit: upper humidity tolerance of 60%, as recommended in SANS 204 and lower Clo value of 0.5. 2. For the winter lower thermal comfort limit: lower humidity tolerance of 30%, as recommended in SANS 204 and higher Clo value of 1.

Figure 5: Left acceptable operative temperature ranges for naturally conditioned spaces (obtained from ASHRAE 55, 2004) and right illustration of average temperatures for Irene (obtained from Climate Consultant)

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Figure 6: Acceptable range of operative temperature and humidity for air conditioned spaces (ASHRAE 55) Building material thermo physical properties Building material thermal properties such as density, specific heat capacity and conductivity were obtained from the Ecotect materials library, South African Clay Brick Association, SAN 204 and from Clarke et al., 1990. See Figure 7 and Table 1 for the input materials thermal properties.

Figure 7: Thermal property values for sections (1,2 and 3, see Figure 4) of the classroom wall

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Table 1: Thermal property values

Occupancy

In the Ecotect model, occupancy was simulated using an annual operation schedule. This assumes that learners are in the classroom during weekdays from 07h00 until 15h00 (Figure 8) with no occupancy during weekends. Heat output per reading learner (55 W) was used as defined in Ecotect. The internal heat load profile was calculated on the basis of this annual occupancy schedule.

Infiltration Infiltration rate is measured in air changes per hour (ACH), and specifies air leakage within the zone through cracks and gaps. This rate ranges from 0.25 ACH for airtight buildings to 2.0 for leaky ones (based on the Ecotect software database). In this case an Infiltration value of 0.5 ACH and a wind sensitivity of 0.5 ACH was selected for all the thermal zones.

Ecotect model calibration The calibration process, used here, compared the results of the simulation with real-world measured data. An alternative calibration method involves comparing results of the same thermal model from two different thermal modelling software packages (inter-model comparison). A limitation of intermodel comparisons is that there is no known â&#x20AC;&#x153;right answerâ&#x20AC;? against which to measure the absolute accuracy of the predictions. Calibration of simulation models is necessary for accuracy and usability of building analysis simulation software. The simulation model used in the calibration considered closed windows and doors and no occupancy of learners as was the case during field study. 208

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temperature (degrees celcius)

Calibration results

Time of day Figure 8: Modelled vs. measured results 13 June â&#x20AC;&#x201C; 15 June The results of Figure 9 showed that, in general, the model under-estimates indoor air temperatures when compared with the measurements for the same period. The reasons for differences between the measured and the modelled data could inter alia be attributed to the following: 1. Inaccuracy of input data: thermal properties of the building materials, building infiltration rates and wind sensitivity. 2. Measurement errors: Temperature sensors give a much localized spatial value that will usually have some radiant component, while simulation tools typically provide spatially averaged temperatures. Thus, some disparity between the two sets of results is to be expected. The performance of this model to replicate data, and hence make predictions, can be considered adequate. The model accurately predicted daily maxima and minima and diurnal variation with average error of 6.5%.

Analyses of the calibrated classroom model Heating and cooling loads To simulate the thermal loads, the type of system was illustratively â&#x20AC;&#x153;switchedâ&#x20AC;? to full air conditioning (for all thermal zones except the attic (roof void) zone). This was done to artificially investigate how much cooling or heating energy could be required in order to offset the thermal loads keeping each of the zones within the target thermal comfort temperature limits (as discussed above in paragraph 2.3.1.2). The thermal load simulations results reported here are for zone E3 (Figure 9 and Table 2). The results of Figure 9 and Table 2 were produced by Ecotect with the following input parameters: 1. Occupancy of 45 learners controlled by the occupancy schedule of paragraph 2.3.1.4. 2. Thermal comfort band of 21-24.5 as calculated in paragraph 2.3.1.2. The green building handbook

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Figure 9: Predicted Annual heating and cooling loads in Wh for calibrated model (Zone E3)

Table 2: Predicted Annual heating and cooling loads for calibrated model (Zone E3)

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Figure 9 shows that cooling load is predominant. Table 2 indicates that a total heating load 430.3 kWh and total cooling load of 4 609.7 kWh is required. This shows that students experience uncomfortably hot temperatures for a much longer time than uncomfortably cold temperatures. From this it can be hypothesized that passive cooling strategies will help to improve comfort more than passive heating strategies. The winter heating load is small because of a very high occupancy of 45 learners in a small floor area of 56.2 m2. The difference between measured indoor air temperature for an occupied classroom in winter and the lower thermal comfort band is small (2 oC from results of the study done by Gibbert et al, 2012), thus the amount of heating energy required to raise the indoor air temperature to thermal comfort is low. For summer the difference between the upper thermal comfort limit (24.5) and the summer indoor air temperatures is big (averaging 6oC from results of the study done by Gibbert et al, 2012). This big difference explains the need for more cooling as compared to heating.

Results of parametric studies Single material parametric studies Ceiling insulation Two types of ceiling insulation, i.e. Neopor and glass wool, were applied above the Gypsum board ceiling. In both cases the thickness was increased in steps of 50 mm resulting in a commensurate improvement of insulation.

Figure 10: Effect of varying Neopor ceiling insulation on thermal loads for zone E3

Figure 11: Effect of varying glass wool ceiling insulation on thermal loads for zone E3

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Discussion of ceiling insulation The results on the total energy load, in relation with the thickness of ceiling insulation materials (Figures 10 and 11), indicate that there is an optimum or economical thickness, beyond which negligible improvements are realised. The implication is that there is an ideal thickness of ceiling insulation. That point is reached at 100 mm for Neopor and 150 mm for glass wool. These materials are both high R-value materials with the former having highest R-value. Ceiling insulation is an appropriate measure that dramatically reduces the cooling load in the case study. This result was expected due to the reduction of interzonal heat flow from the very hot attic zone to the classroom zone during summer periods. Thermal bridging is a challenge in ceiling insulation installation. BRANDZ, a research organisation in New Zealand that investigates the construction and design of buildings, assessed thermal performance of different ceiling insulation installations using heat flux transducers for measuring thermal resistance. The finding was that installing insulation between and on top of ceiling brandering or truss tie-beams gives the best R-values.

Roof solar absorptance Solar absorptance is a measure (ranges from 0-1) of the proportion of solar radiation that is absorbed by a material. Solar reflectance refers to the fraction of solar radiation that is reflected back to the atmosphere. Therefore, a surface with high solar reflectance value has low solar absorptance value. Roof solar absorptance values were varied from 0.3 (white surfaces) to 0.9 (dark surfaces). The values for roof absorptance were obtained from SANS 204: 2011.

Figure 12: Effect of varying roof absorptance on thermal loads for zone E3 Discussion for roof absorptance

White, low-absorptance roof reduces thermal loads significantly by 28.9% (Figure 12). In this case a white colored roof is highly recommended. Dust and dirt increases the solar absorptance, therefore periodic preventative maintenance by washing the roof needs to be done.

Attic ventilation The ventilation flow rate in the attic was varied from 0.5 to 20 ACH and the impact on thermal load predicted (Figure 11). Attic ventilation for this case can be achieved through introducing turbine 212

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ventilators and or large ventilation grills on both east and west gable ends. A study of Pretoria wind roses indicate that the predominant summer wind direction for the site is east (Figure 15).

Figure 13: Effect of varying attic ventilation flow rate on thermal loads for zone E3

Discussion for attic ventilation

Attic ventilation reduces the thermal load of the case study classroom. An increase in the attic ventilation rate results in a decrease of cooling thermal load for the classroom. Although the predominant summer wind direction for the site is easterly in the direction hitting the attic ventilation directly, a high ventilation rate is required to have a significant reduction in the cooling load. This is unlikely to be achieved solely by natural ventilation. The potential of wind turbine ventilators to provide high attic ventilation rates in low wind areas like Pretoria needs to be assessed. The green building handbook

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TECHNOPOL ENERGY EFFICIENT BUILDING PRODUCTS Technopol established in 1993, manufactures and supplies Expanded Polystyrene Insulation Products to both domestic and export markets. In our Springs factories we mould and process Expanded Polystyrene Products into a multitude of Insulation Solutions. As a bulk Insulation producer, we work closely with consumers and contractors to develop systems for the building Industry. We manufacture Insulation Elements for Wall, Roof and Floor Applications. All our products are Fire Retarded and produced without using any CFC’s of HCFC’s. Technopol is a founder member of both the Expanded Polystyrene Association of South Africa and Thermal Insulation Association of SA and we are proud to be part of the initiative to protect our environment by implementing energy efficient living.

Let’s look at the price we pay for thermal comfort

If you can afford electricity, remember the irresponsible consumption of this resource results in fossil fuel emissions polluting our environment, i.e. Sulphur, CO2 and NOx (GHG Emissions). For those who can afford air-conditioning equipment, be reminded they contribute to the HCFC build up in our atmosphere. We now know that HCFCs have a thousand times the heat trapping ability of CO2. If the reduction of GHG emissions is our objective then HCFC liberating processes should be reduced. If you can’t afford the above, you have to burn coal and wood to prevent element exposure. This could damage your lungs and cause respiratory diseases thus placing major cost pressures on the health care system in SA. All this while creating smoke pollution and liberating more GHG.

The solution is so simple

Design energy efficient and introduce sufficient thermal insulation and see the benefits: • Energy costs for space heating and cooling will reduce by between 35 and 60 percent. • Energy resource will be conserved. • Pollution will be reduced. • GHG emissions will reduce. • Occupants will be healthy because of the thermal comfort of their dwellings. All these benefits for less than 10% of the average building cost.

Lammie de Beer,Managing Director Technopol (SA) Pty Ltd, 9 Wright Road Extension Nuffield P.O. Box 2445, Springs, 1560 Telephone: 011 363 2780 Fax: 011 363 2752 Email: info@technopol.co.za Website: www.technopol.co.za 214

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Wall insulation Neopor wall insulation was varied in steps of ten and the impact on thermal load predicted (See Figure 14).

Discussion for wall insulation Wall insulation in this case reduces the heating loads significantly during winter. However wall insulation in this case increases the cooling load much more than it reduces heating loads. Since the dominant thermal load is cooling in this case, wall insulation alone is not that beneficial.

Figure 14: Effect of varying wall insulation on thermal loads for zone E3 Summer natural ventilation An annual operational schedule for natural ventilation through windows was set in Ecotect. The schedule assumed that all windows and doors were fully opened to give the maximum natural ventilation flow rate. The ventilation rates were varied from 2 - 20 ACH and the number of annual hours which exceeded 26.5 oC in summer was calculated.

Table 3: Impact of summer natural ventilation rates on thermal comfort

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Discussion for natural ventilation Table 3 shows that an increase in the natural ventilation rate significantly reduces the number of too hot discomfort hours. A wind analysis (Figure 15) done for a site close to David Hellen Petta school i.e. Berea sports grounds in central Pretoria, shows that the wind direction during summer months is predominantly East. The window openings for the classroom are located to the North and South. Therefore the design for the classroom does not promote natural cross ventilation. This implies that high summer ventilation rates are not easily achievable hence poor air quality and overheating in the classroom during summer even though windows are fully opened as shown by a study by Gibbert et al, 2012. Interventions such as installation of solar powered ceiling mixing fans may help alleviate the overheating problem.

Figure 15: Wind rose for Berea sports ground generated by Climate Consultant using Meteonorm data

Combination of materials Ceiling insulation combined to wall insulation Two variables (ceiling insulation and wall insulation) were varied simultaneously and the thermal loads predicted (See Table 4).

Table 4: Effect of combination of ceiling and wall insulation on thermal loads for zone E3 The green building handbook

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Discussion of ceiling insulation combined to wall insulation A combination of ceiling and wall insulation lowers both heating and cooling loads significantly by up to 28.1%. Therefore this combination will ensure comfort in both winter and summer seasons. However ceiling insulation alone has a higher thermal load reduction potential of up to 31% when compared to the combination. In climates like Pretoria where there is predominantly a need for summer cooling, the location of insulation must be carefully considered. This research in this case indicated that ceiling insulation is more beneficial than wall insulation.

40mm wall insulation plus 150mm ceiling insulation combined with roof absorptance In this case the best thermal performance design of Table 4 was selected. To this wall and ceiling insulation were fixed and the roof absorptance was varied (Table 5 for predicted thermal loads).

Table 5: Effect of ceiling insulation combined to wall insulation and roof absorptance on thermal loads for zone E3 Discussion for combination of materials The net result of combining different interventions are not always as beneficial as expected because they might neutralise the beneficial effects when seen in isolation. For example it was expected that a roof absorptance of 0.3 could have had a further reduction in the energy load of 28% when combined with a 40 mm wall insulation plus 150 mm ceiling insulation. Unfortunately this resulted in a mere 2% further reduction. It is therefore inappropriate to combine (add) results from individual components directly to determine the total thermal load reduction potential of a group of strategies. The green building handbook

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BUILDING THERMAL LOADS

Conclusions This research has investigated the possible impact of passive interventions on building thermal loads for David Hellen Petta public secondary school. The findings provided useful indications which can be used by building designers in retrofitting public school buildings in climatic regions similar to that of David Hellen Petta. Results indicate that ceiling insulation has the greatest potential for reducing thermal loads by up to 31%. The second most effective measure is a combination of 40 mm wall insulation, 150 mm ceiling insulation and a 0.3 roof absorptance leading to a reduction of 30.4%. The third most effective measure is by painting the roof white (0.3 absorptance value) leading to a reduction of 28.9% (See Figure 12). The fourth method is to use a combination of 40 mm wall insulation and 150 mm ceiling insulation that realises a reduction of 28.1%. A combination of wall and ceiling insulation reduces both heating and cooling loads significantly. Therefore a combination of wall and ceiling insulation performs well in both winter and summer. Apart from climate considerations, the operation schedule for the building need to be taken into account of when selecting appropriate passive interventions for a building design. Whole day strategies might not be the same as partial day strategies. The fact that ceiling insulation in this case has the greatest potential in reducing building thermal loads supports the hypothesis that heat gains in Pretoria occur mostly through the roof and ceiling. This is due to the fact that the solar trajectory is almost overhead in summer.

6 References ANSI/ASHRAE Standard 55-2004 Thermal Environmental Conditions for Human Occupancy. Conradi. D. 2011. Designing for South African Climate and Weather. Chapter 11. The Green Building Handbook South Africa Volume 4. The Essential Guide. Department of Basic Education. 2010. Education Statistics in South Africa. Gibberd J., Motsatsi L. and Baloyi N. 2012. An investigation into indoor environmental quality in a classroom. Building Performance Laboratory PG report. Applied Phase of the Building Perfomance Laboratory. Technical Report No: CSIR/BE/BST/R/2011/0053/B GWDMS No. 202053.

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PROFILE

arcelormittal ArcelorMittal South Africa is the largest steel producer on the African continent, with a production capacity of 7,8 million tonnes of liquid steel per annum. The company has a depth of technical and managerial expertise carefully nurtured since 1928, a reputation for reliability and a sharply defined business focus, which has forged the organisation into a modern, highly competitive supplier of steel products to the domestic and global markets. ArcelorMittal South Africa’s global standing is further underpinned part of the world’s largest steel producer, the ArcelorMittal Group.

Core Services

ArcelorMittal South Africa’s steel is used in various projects for critical infrastructure in South Africa. These include: • Construction • Transport systems • Electricity transmission and distribution systems • Telecommunications networks • Water supply and treatment • Fuel supply systems Domestically the company plans to expand its position in the market through development of new products and growth of the downstream industry, while focusing its international attention on selective export markets, particularly in Africa.

Company Strategy

ArcelorMittal South Africa has set clear goals for itself as it enters the next phase of its journey towards transformation. The board of ArcelorMittal South Africa has developed and approved the following strategic goals: • Industry leading value-creation for shareholders • Positive economic value add over the steel price cycle • Improving operating capabilities • Value-creating throughput increases • Substantial reduction in hot rolled coil/billet cash cost in real terms • Building on the existing performance culture • Create an environment that generates true employee pride and attracts, develops and retains top performing people and Being a responsible corporate citizen. The drive for operation excellence is supported by the Group’s global presence which gives ArcelorMittal South Africa access to a unique knowledge base.

Markets

ArcelorMittal South Africa is the major supplier to the Southern African steel market. With its wide range of products, it services the construction and heavy engineering sectors, pipe and tube manufacturers, the automotive market, as well as the furniture and appliance manufacturing industries. High strength plate and hot rolled strip are used for heavy commercial vehicles and mining equipment. Galvanised and pre-painted sheet are used widely for roofing, cladding and rainwater goods, while tinplate and cold rolled sheet are used for a range of applications in the packaging industry. Its wire The green building handbook

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PROFILE rod is transformed into cable and fencing material and utilised by fastener manufacturers. Domestically the company plans to expand its position in the market through development of new products and growth of the downstream industry, while focusing its international attentions at selective export markets, particularly in Africa.

Product Branding /Marking

We pride ourselves in our brands, trademarks and logos which stand for sustainability, quality and leadership. This is why we make sure that we brand/mark our products with our logos. This guarantees you that the products are genuinely from ArcelorMittal and they are of good quality. It is very important to know what you are buying as the quality of the material you use is pivotal to the sustainability and quality of your projects regardless the size. Steel is generally regarded as a rigid material offering only strength. This is not true of ArcelorMittal South Africa’s galvanised sheet used as substrate for Chromadek®. It is readily formable which makes it eminently suitable for a wide variety of end-uses in the building industry. The formability of the substrate is matched by the flexibility of the paint system – two characteristics desired by architects, profilers and developers. Chromadek® is lighter than any other roofing material, providing roofs of up to 80% lighter than those using concrete tiles. This saves on the roof structure, construction time and equally important – cost. Chromadek® offers great versatility for roofing and cladding applications. South African architects use Chromadek® in a variety of roofing and cladding projects ranging from churches, shopping malls, factories, warehouses and airports to luxury eye-catching homes and large housing estates. Chromadek® is exceptionally colour fast. Warrantees are given on application, subject to certain conditions. The African Heritage Colour Range of 14 exciting colours captures the essence of the African environment and reflects the continent’s unique colours and hues, allowing designers the freedom of expression. Over and above its aesthetic attributes, Chromadek® paint coatings are designed to provide superior corrosion protection under conditions where the performance of unpainted galvanised sheeting may prove inadequate. Furthermore, the coatings exhibit excellent formability and elasticity to facilitate roll profiling and bending operations without damage to the paint coating.

Heat reflective Chroamdek®

Two of the colours of the Chromadek® range (See Data Sheet C1.4), Charcoal Grey and Dark Dolphin, are produced by utilising an advanced thermal technology paint system. This advanced paint system incorporates a heat reflective pigment into the paint providing up to 8°C cooling effect and improved durability. The durability of an exterior coating is measured according to its capability of maintaining gloss, colour and film integrity.

Light Steel Frame

Light Steel Frame building is part of a fast growing innovative building solution that offers a modernist and fresh approach to creating space for living and working with the benefit of contributing towards a suitable environment. The features of light steel frame buildings include structural integrity, speed of construction, thermal 222

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PROFILE insulation, dimensional accuracy and high quality finishes. Steel lends itself to a category of construction materials that is recyclable. A light steel frame building consists of steel sections, selected for their structural and mechanical properties in accordance with the national standard for light steel frame building, SANS 517. In addition these sections are galvanized for corrosion protection, ensuring the longevity of the structure.

Steel Recycling

Steel is one of the most recycled materials in the world. ArcelorMittal is the biggest recycler of scrap steel in the world, which cuts down on around 36 million tons of carbon dioxide. One of the most successful projects that we are involved in is Collect-a- Can. Recovery rates of steel cans in South Africa have risen from just 18% to around 70% in the years since the initiative was set up, preventing the cans from being sent to landfills.

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net zero waste

chapter: 10

Net Zero waste

Gordon Brown CEO Alive2green According to the World Green Building Council the construction sector accounts for up to 40% of waste in landfill sites worldwide, and while this figure may be lower in South Africa construction remains a significant contributor to landfill content. The National Waste Information Baseline Report (DEA2012) indicates that the construction sector is responsible for 8% of all waste generated, although it is unclear whether this number includes the waste from product suppliers during production, which is significant. Importantly this statistic also excludes the ongoing operational waste generated in all occupied buildings, and so is understated. Construction waste is made up of aggregates (concrete, stones, bricks) and soils, wood, metals, glass, biodegradable waste, plastic, insulation and gypsum based materials, paper and cardboard, a very high percentage of which are reusable or recyclable if separated at source. Currently 16% of construction waste is recycled in South Africa (NWIBR). TRENDS AND FORCES FOR CHANGE The green building movement is being spearheaded by the CSIR and the Green Building Council of South Africa, the latter having set up rating tools that award points for, amongst other green building aspects, resource efficiency for designs which reduce waste. BEST PRACTICE Construction waste emanates due in some part to inconsiderate design, construction, maintenance, renovation and demolition, as well as supplier considerations such as packaging. Intelligent design and best practices during each phase can significantly reduce waste. Design: Architects and engineers have a very significant opportunity to affect the waste generated through the life cycle of a building by determining the method of construction and the materials specified. From simple strategies like utilising building rubble onsite as fill for instance, or reusing items from demolished buildings such as wooden window frames, by specifying materials with recycled content, and adopting strategies and building methods geared to dismantling and designed for deconstruction - design affects everything, and with careful planning and consideration given to waste and reusing materials at concept stage, much waste to landfill can be avoided. An example of this is modular construction.

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net zero waste

It is also very important at design stage to consider how the building is going to manage operational waste while the building is occupied – sufficient space will be required for recycling storage and sorting, as well as the access to various floors and of course for collection. Construction: At a waste management level, there are a number of best practices to ensure maximum recyclability of materials on site: • • • • • • •

Make this consideration a key performance criterion when appointing contractors Set targets for % of waste not to go to landfill (refer to Green Star SA for achievable best practice) Have a waste management plan drawn up according to best practice prior to beginning the project (ie. Part of the tender/brief document) Have correctly marked skips for certain waste streams Ensure that the correct paper work is filed for all items removed from site Safe disposal tickets for hazardous waste must be kept Keep a monthly and overall project reports of all waste and at the conclusion of the project – confirm whether targets are being achieved

There are many great examples of achieving excellent standards in construction waste management, one of these was the first Green Star SA certified project in South Africa, the Nedbank Phase II building in Sandton – in 2008 the contractor was initially concerned about the high standards set within Green Star SA for waste diverted from landfill (30, 50, or 70% of construction waste). By the end of the project, with the good waste management programme they employed, they were surprised at the incredible success – they were able to divert over 90% of their construction waste from landfill. This is a significant achievement, and is replicable across all construction projects by implementing good waste management programmes. Product and Material Suppliers suppliers have huge potential to reduce the amount of waste going to landfill. Many suppliers could provide their materials to site in a way that requires less or no ‘packaging’, or packaging that is recyclable, and also ensure that their contract with the construction contractors is such that their packaging is returned to them directly for recycling or reuse. ‘Packaging’ is significant 226

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waste source. (Packaging refers to anything that is not the actual material that will be used and left installed on site.) Besides the ‘packaging’ referred to, the product suppliers are also responsible for a significant amount of waste at their own factory or storage houses – the contractors and design team can have a significant influence on the downstream waste impacts by contracting only with suppliers that minimise their waste production and maximise recycling and reuse of waste. The building in operation: During the course of a buildings life it will require multiple new light bulbs, new carpets and flooring, painting, filling, stripping, windows due to breakages etc. Good building managers and operators can make the necessary effort to separate materials. The Green Star SA rating tools will reward designers for making provision for separation operations within the utilities area of the building, and building maintenance would utilise these facilities for its waste streams. It is important to have both the space designed to store and sort the waste for collection, but also to have waste management policies in place for the ongoing operation while the building is occupied. MARKET FORCES As the market places a greater value on sustainability, products with recyclable content become more sought after. Masonry bricks made from crushed aggregates, tiles made from recycled plastics, are just two examples of products gaining traction. On the waste disposal side, costs are rising but it remains relatively cheap to dispose of construction waste to landfill, cheaper in fact than general waste disposal which costs R272.00 per ton. As costs increase so too does illegal dumping, which poses an environmental problem, and municipalities need to consider increasing the penalties imposed on transgressors and to find ways of policing illegal dumping more effectively. Perhaps funds from increased charges for legal dumping can be directed in part to policing illegal dumping. The construction sector has a massive impact and a commensurate opportunity to effect positive and meaningful change. Through a combination of product design and innovation, building design and methods, and through best practice waste management on site the sector can radically reduce the amount of waste created and significantly improve on the rate of recycling. REFERENCES Republic of South Africa, 2009. National Environmental Waste Act, No 59 of 2008 Waste Management Plan, Malelane Safari Resorts National Waste Information Baseline Report, Draft 6, 5 September 2012 Green Building Council of South Africa – Manfred Braune, Technical Executive The green building handbook

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index of advertisers

PROFILE

COMPANY

PAGE NUMBER

AAAMSA

118, 119, 120

AFRICAN WATER CONTROLS

68, 69, 70

AKISA ARCHITECTS

150

ALUGLASS BAUTECH

114

ANDREW NIMMO ARCHITECT

ARCELOR MITTAL

221, 222, 223, OBC

BASF 6 BELGOTEX

135, 136, 137

BLUESCOPE STEEL

28, 58, 59

BOOGERTMAN & PARTNERS ARCHITECTS

55, 56, 57

CAMFLY

186

CEMENT AND CONCRETE INSTITUTE

98, 99

COROBRIK

198, 199, 200, 201

CRAMMIX 30 DPI PLASTICS

188

ECO WARMTH

218

EMERGENT ENERGY

36 ,38 ,40

ERGOSYSTEMS

2, 3

ETTENAUER SA

GEBERIT 78 HONEYWELL AUTOMATION

ICI DULUX

20, 21, 24

IMBONO FJA ARCHITECTS

144

JOJO TANKS

KYASOL

LANGKLOOF BRICKS

156, 157

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index of advertisers

PROFILE

COMPANY

PAGE NUMBER

LEBONE ENGINEERING

121, 122,123

LYT ARCHITECTURE

195, 196, 197

METROTILE

72, 73

MIBT 88 MODENA 8 NICHOLAS PLEWMAN ARCHITECTS

16, 18, 19

PLASCON

IFC, 1

POLYMER PROFILES

216

RABANA ARCHITECTS

95, 96, 97

RIAAN STEYN ARCHITECTS

160, 161, 164

RICKARD AIR DIFFUSION

190

SA INSTITUTE OF ENTREPRENEURSHIP

182

SA VINYLS ASSOCIATION

230, 231

SAFAL STEEL

SAINT-GOBAIN

SASOL

232, IBC

SHORROCK AUTOMATION

104

SIKA 10 SOVENTIX 62 TCTA

TECHNOPOL 214 UNIVERSITY OF FORT HARE

175, 176, 177

UNIVERSITY OF PRETORIA

192

VERSUS PAINTS

112

VOIDCON

178, 179

VREDE TEXTILES

133, 134

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is endorced by through its Product Stewardship Programme.

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

ArcelorMittal South Africa

Did you know? is now heat reflective Two of the colours of the Chromadek® range Charcoal Grey and Dark Dolphin, are produced by utilising an advanced thermal technology paint system. This advanced paint system incorporates a heat reflective pigment providing improved durability and a cooling effect of up to 8°C. The durability of an exterior coating is measured according to its capability of maintaining gloss, colour and film integrity. Heat reflective Chromadek® offers the following benefits: • Increased durability. - Increased gloss retention. - Improved colour stability (less fading). - Sustainable film integrity. • Reduced heat transfer into buildings. ArcelorMittal’s products are branded and/or marked for your protection We pride ourselves in our brands, trademarks and logos which stand for sustainability, quality and leadership. This is why we ensure that, where applicable, we brand/mark our products with our logos and product information. This guarantees you that the products are from ArcelorMittal and of the highest quality. It is very important to know what you are buying as the quality of the material you use is pivotal to the sustainability and quality of your projects - regardless the size. Some of the ArcelorMittal South Africa products that are branded and/or marked are plate, galvanised coil, Chromadek® and rebar. Steel is infinitely recyclable Steel is one of the most recycled materials in the world. ArcelorMittal is the biggest recycler of scrap steel in the world, which cuts down on around 36 million tons of carbon dioxide. One of the most successful projects that we are involved in is Collect-a-Can. Recovery rates of steel cans in South Africa have risen from just 18% to around 70% in the years since the initiative was set up, preventing the cans from being sent to landfills.

If you need more information contact us at chromadek@arcelormittal.com tel 016 889 4870 or www.arcelormittal.com/southafrica