Strategies to achieve energy efficiency through retrofit of existing apartment in warn humid climate

Strategies to achieve Energy efficiency through Retrofit of existing Apartment in warm humid climate of Chennai, India

A DISSERTATION

Submitted for the fulfillment of the degree MSC Sustainable Architectural Studies

School of Architecture The University of Sheffield

Sudheer Alavala Venkata Rama August 2013

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Declaration

All sentences or passages quoted in this dissertation from other people's work have been specifically acknowledged by clear cross-referencing to author, work and page(s). Any illustrations which are not the work of the author of this dissertation have been used with the explicit permission of the originator (where possible) and are specifically acknowledged. I understand that failure to do these amounts to plagiarism and will be considered grounds for failure in this dissertation and the degree examination as a whole.

Name: Sudheer Alavala Venkata Rama Signature: Date: 05-08-13

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Abstract Energy requirements and energy efficiency are two important categories for a developing country like India due to the fact that it is under severe pressure for energy requirement and migration of people to cities increasing the demand for energy. Buildings require energy from the grid and through renewable sources. Existing housing needs to be focused on as they consume more energy for the running of the building compared to the new construction housing. This study focuses on the existing housing projects of south India where the climate is warm and humid. Current passive cooling principles and strategies do not work well in this part of the country in terms of materiality. Hence different methodologies need to be adopted to cut down the energy loads of existing housing.

The Aim is to demonstrate methods for reducing the energy consumption through the application of various vernacular materials with less embodied energy for the wall element and compare the embodied energy against energy in use. A new IGBC-LEED green rated housing building is analyzed for its design principles, comfort levels, type of materials used and construction type to understand the IGBC-LEED standards. These ideas are then transposed to the retrofit of an existing structure using the chosen materials and simulated to compare their performance. Several materials are analyzed in this manner for energy efficiency and the best performing material is chosen for the wall element of the retrofit house.

The findings from this research show that the compressed stabilized earth blocks (CSEB) perform the best for the wall element of the building due to its physical properties and the least embodied energy among the chosen materials for analysis. 13.68% embodied energy against the energy in use for one year is observed for CSEB bricks. 16.52% energy savings from the base case is observed for CSEB for the annual energy in use per kWh. A wider question is asked as there were differences from a theoretical and practical research for an overall retrofit of the apartment.

Keywords: Energy consumption, Embodied energy, Vernacular materials, Retrofit of house.

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Acknowledgements I take this opportunity to thank several people who have been part of the journey.

First and foremost, I deeply thank my supervisor Fionn Stevenson for her guidance and ideas that helped me at all stages of the Dissertation. I thank her for the support and strength that was given to me which boosted the confidence in doing a deep research on the topic.

I would like to thank my parents for all the support and faith they had in me to do the Masters degree. I would specially thank my father who had given me this education that will help me throughout my life. I dedicate this Dissertation to my parents from the bottom of my heart.

I would also like to thank an Architect Mr. Anup Naik from Space Matrix, Bangalore who had sent me valuable information regarding case study and Mr. Jaideep Vivekanand, Green Evolution in Chennai who took time and provided valuable information regarding a case study project.

More importantly, I would like to thank all my friends in Sheffield and India who had supported and guided me through various doubts and discussions over the course of the Dissertation.

Sudheer Alavala Venkata Rama

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Table of Contents Declaration .................................................................................................................................................... 2 Abstract ......................................................................................................................................................... 3 Acknowledgements....................................................................................................................................... 4 CHAPTER 1 - INTRODUCTION ...................................................................................................................... 10 1.1 - Background on Retrofitting: ........................................................................................................... 10 1.2 - The Problem with Energy Trends:................................................................................................... 11 1.3 - Aims and Objectives........................................................................................................................ 13 CHAPTER 2 - Research Methodology .......................................................................................................... 15 2.1 - Research process through Diagram ................................................................................................ 15 2.2 - Literature Review - To refine the process....................................................................................... 16 2.3 - Identifying factors to analyze and why ........................................................................................... 17 2.4 - Establishing embodied energy/carbon data/ substitution of materials ......................................... 17 2.5 - Introduction to simulation and analysis ......................................................................................... 18 2.5.1 - Design Builder .......................................................................................................................... 18 2.5.2 - Method of Simulation .............................................................................................................. 18 CHAPTER 3 - LITERATURE REVIEW .............................................................................................................. 20 3.1 - Power Sector in India ...................................................................................................................... 20 3.1.1 - Electricity use of India .............................................................................................................. 21 3.1.2 - Tamil Nadu - Profile for Energy Efficiency ............................................................................... 22 3.2 - Background on Retrofit Scenario in India ....................................................................................... 22 3.3 - IGBC Green Homes Certification Levels .......................................................................................... 23 3.3.1 - Low carbon building example .................................................................................................. 24 3.4 - Climate of India and Tamil Nadu..................................................................................................... 25 3.5 - Apartments in Chennai, Tamil Nadu ............................................................................................... 27 3.5.1 - Benefits from Retrofitting: ....................................................................................................... 27 3.5.2 - Small Reduction Saving Opportunities: ................................................................................... 28 5

CHAPTER 4 - BUILDING CONSTRUCTION MATERIALS & EMBODIED ENERGY ............................................ 30 4.1 - Green Building Materials ................................................................................................................ 30 4.2 - Life of a construction material ........................................................................................................ 30 4.3 - Materials selection.......................................................................................................................... 32 4.4 - Embodied energy in Building materials/transportation ................................................................. 32 6. Fly Ash Bricks....................................................................................................................................... 35 4.5 - Analysis/Substitution of building materials for the retrofit case study.......................................... 37 CHAPTER 5 - CASE STUDIES ........................................................................................................................ 41 5.1 - SHEMPARK APARTMENTS ............................................................................................................... 41 5.2 - BCIL TZED HOMES ........................................................................................................................... 45 5.3 - VIKAS APARTMENTS, AUROVILLE ................................................................................................... 48 5.4 - SUMMARY/ANALYSIS OF THE CASE STUDIES.................................................................................. 52 CHAPTER 6 - RETROFIT OF APARTMENT - A CASE STUDY ........................................................................... 53 6.1 - Introduction of the existing project ................................................................................................ 53 6.2 - Simulations in Design Builder ......................................................................................................... 55 6.3 - Comparison of Embodied energy against energy in use for wall element ..................................... 57 6.4 - Analysis of material for % embodied energy against total energy in use ...................................... 58 6.5 - Analysis of difference in the energy use (AE) of different materials............................................... 59 6.6 - Analysis of materials for their availability, distance and skilled labour.......................................... 60 6.7 - Life expectancy of the materials ..................................................................................................... 61 6.8 - Analysis of the material life & Summary of Energy retrofit ............................................................ 62 CHAPTER 7 - DISCUSSION............................................................................................................................ 63 CHAPTER 8 - CONCLUSION .......................................................................................................................... 66 8.1 - Summary of the Research ............................................................................................................... 66 8.2 - Limitations of the Research ............................................................................................................ 67

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8.3 - Further Research............................................................................................................................. 67 REFERENCES ................................................................................................................................................ 68 BIBLIOGRAPHY ............................................................................................................................................ 72 Appendices.............................................................................................................................................. 74

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Table of Figures Figure 1: CO2 emissions from buildings – IPCC High Growth Scenario ...................................................... 10 Figure 2: Commonly identified energy efficiency technology needs in buildings and residences ............. 11 Figure 3: Distribution of Household Monthly Electricity Consumption (2005) .......................................... 12 Figure 4: Climate and Development Indicators: India, China, US and EU................................................... 13 Figure 5: Power Plant Utilization Improvements ........................................................................................ 20 Figure 6: Power generation in India ............................................................................................................ 21 Figure 7: Distribution of electricity consumption by income class ............................................................. 21 Figure 8: Embodied carbon of the pilot study ............................................................................................ 25 Figure 9: Climate zone map of India ........................................................................................................... 25 Figure 10: Average temperature graph of Chennai, India .......................................................................... 26 Figure 11: Region of Tamil Nadu, India ....................................................................................................... 27 Figure 12: Life cycle phases of buildings ..................................................................................................... 28 Figure 13: Small savings from large numbers of end-use units .................................................................. 29 Figure 14: The cycle of materials ................................................................................................................ 30 Figure 15: Log construction ........................................................................................................................ 31 Figure 16: Classification of materials as per energy intensity .................................................................... 32 Figure 17: Comparative energy requirements for various building materials............................................ 33 Figure 18: Transport energy costs for India ................................................................................................ 33 Figure 19: Diagrammatic representative of flyash brick manufacturing process ....................................... 35 Figure 20: Energy savings achieved through Flyash Brick over other materials......................................... 36 Figure 21: Embodied energy involved in transportation of building materials in India ............................. 37 Figure 22: Chosen materials for the retrofit ............................................................................................... 39 Figure 23: wall assembly of flyash bricks .................................................................................................... 40 Figure 24: Route Map to Shempark ............................................................................................................ 41

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Figure 25: The figure showing the typical floor plan of the Apartment complex....................................... 42 Figure 26: Apartment unit A, Shempark ..................................................................................................... 42 Figure 27: 3d perspective view of shempark Apartments .......................................................................... 43 Figure 28: Passive Solar design, elevation treatment ................................................................................. 43 Figure 29: Roof Coating at Shempark ......................................................................................................... 44 Figure 30: Solar water heaters at Shempark .............................................................................................. 44 Figure 31: Map to go to TZED ..................................................................................................................... 45 Figure 32: Apartment type - 1, BCIL TZED ................................................................................................... 46 Figure 33: Apartment type - 2, BCIL TZED ................................................................................................... 46 Figure 34: Apartment 1 & 2 - BCIL TZED ..................................................................................................... 47 Figure 35: Apartments 1 & 2, Vikas ............................................................................................................ 49 Figure 36: Overall layout of vikas apartments ............................................................................................ 50 Figure 37: Elevation of the vikas apartment ............................................................................................... 50 Figure 38: Section of the apartment building, Vikas................................................................................... 51 Figure 39: 3d view of the retrofit apartment .............................................................................................. 53 Figure 40: Typical Floor plan of the Retrofit Apartment ............................................................................. 54 Figure 41: Design Builder model of the Retrofit Apartment....................................................................... 56 Figure 42: Energy analysis of different wall materials ................................................................................ 57 Figure 43: Embodied energy against energy in use over one year ............................................................. 58 Figure 44: % of EEEV compared to energy use of the building..................................................................... 59 Figure 45: AE - operational energy of the building ...................................................................................... 59 Figure 46: Annual energy saving from the base case ................................................................................. 59 Figure 47: Energies of various mode of transport ...................................................................................... 61 Figure 48: Embodied energy compared to energy in use of materials over 100 years .............................. 62

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CHAPTER 1 - INTRODUCTION 1.1 - Background on Retrofitting: According to the fourth assessment report of IPCC, the global greenhouse gas emissions due to human activities rose by 70% between 1970 and 2004 (IPCC, 2007). 30% of global annual greenhouse gas emissions are contributed by the building sector which consumes 40% of all energy and is the single largest quantity compared to other sectors. The energy savings and cost effective emission reductions of more than 30% are possible in many countries (fig 1) (LEMMET, 2009).

Globally there is no more cost-effective way to make major cuts in green house gas emissions and in energy use than to retrofit the existing buildings (David Biello, 2011). A study conducted

by Deutsche bank Americas foundation with 22 other non-profit organizations had examined 19,000 affordable housing units in New York city that underwent energy efficiency retrofits had resulted in 19% and 10% savings on fuel bills and electricity which had resulted in to $240 and $70 on both fuels and electricity per Apartment/Yr. The definition of Building Retrofit as quoted by David H Allen, the American expert in energyefficient building improvements states the modification of the property to improve the comfort, energy use, safety, health and durability (DECCAN HERALD, 2012).

Figure 1: CO2 emissions from buildings – IPCC High Growth Scenario Note: Dark red: historic emissions. Light red: projections 2001 – 2030. 2000 – 2010 data adjusted to actual 2000 carbon dioxide emissions. EECCA= Countries of Eastern Europe, the Caucasus and Central Asia. Source: Levine et al, 2007.

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It is clearly seen the Asian continent needs more technology to address Air conditioning costs and means to reduce the electrical bills regarding this need (fig 2).

Figure 2: Commonly identified energy efficiency technology needs in buildings and residences Source: (UNEP SBCI, 2011)

1.2 - The Problem with Energy Trends: India and several developing countries participated in the Bali Action plan 2007 to develop Nationally Appropriate Mitigation Actions (NAMAs). India's strong resistance had led to its reputation as "obdurate" and "unhelpful" for not compromising its development goals and undertaking mitigation actions (The Economist, 2008). The per capita consumption of electricity in India stands at 481kWh as compared to a world average of 2596 kWh which is less than one fifth of the consumption scales (World Resources Institute, 2010). The use of available efficient technologies for cooking, heating, lighting, electrical appliances and building insulation could bring in potential energy savings as high as 75%. The growth rate of per capita household income is slower than the household electricity usage (Chipman, 2011).

More than 40% of India lacks electricity, the use of kerosene for lighting and one-sixth of population use electricity with a consumption of 100 kWh per month as compared to 900 units

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per month for the US (fig 3). India being the second most populous country in the world has less than a quarter of Co2 in both annual and per capita terms as shown in (fig 4), with International Energy Agency (IEA) projecting India's emissions will grow by 4% per year contributing less than 7% of global Co2 by 2020 though India is home to almost a fifth of world's population (International Energy Agency, 2008). The intensity of energy and carbon use can grow if the country's poverty is reduced as the carbon emissions are directly related to income levels (Narasimha Rao, 2009). The existing housing can be upgraded for an improved performance although, it is not feasible to demolish and rebuild due to economic, social, psychological and cultural reasons. However, the interventions for retrofit may range from repairs, strengthening, and even replacement of some elements of the building (R.P.Nanda, 2011). This study looks at the external wall element for the retrofit as a complete retrofit is expensive for the occupant and as the concept of retrofitting housing is new in India compared to the developed countries. In the current scenario, around 35% of all urban households cannot afford housing at market prices and this will increase over the next 20 years. India's lower income groups (<90,000 rupees in tier 2 & 3 cities and <500,000 rupees per year in tier 1 cities like Mumbai) are unable to afford housing with a lot of gaps between demand and supply (Mckinsey Global Institute, 2010). Such section of people can look at retrofit of existing homes which is more cost effective.

Figure 3: Distribution of Household Monthly Electricity Consumption (2005) Source: Prayas Energy Group, India

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Figure 4: Climate and Development Indicators: India, China, US and EU Sources: WRI, European Environmental Agency, US Energy Information Administration, International Monetary Fund, BP Statistical Review 2009.

How can we reduce the amount of energy used by buildings in India by Retrofit?

1.3 - Aims and Objectives An energy and ecologically conscious approach to the design of the built environment such as reduction in the consumption of natural resources and fuels can decrease the green building footprint simultaneously reducing the carbon emissions generating from the building and construction industry (Beattie, 2001). In the face of increasing economic growth of India, housing requirements will increase rapidly in the future especially in the cities. It is in this regard, the specific research aim is to evaluate retrofitting of existing housing / dwelling with a focus on the walls of the structure in terms of embodied energy and energy efficiency. The background review of this topic leads to several key research questions: 1. What are the different means by which energy consumption reduction can be achieved in a Retrofit house/Apartment in warm humid climate of India?

2. What are the different materials that can be substituted for a retrofit considering several factors such as embodied energy and embodied carbon?

3. What would be the percentage of difference in the embodied energy against energy in use for the wall element of the building?

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There is some literature on improving the comfort in homes through other elements of building, user usability and automation controls of appliances (Stevenson, 2012) (Fionn Stevenson, 2013), but can similar comfort be achieved through building fabric changes alone?

Attention towards creating less energy in use building and identifying the right material choice for the wall assembly of the building is the core aim of this research. The virtual non-existence of low carbon retrofit projects for such a climate adds a further challenge to the research. The research aims to explore different vernacular materials of the Tamil Nadu region that are sustainable and adaptable to an existing structure to decrease the overall energy in use of the building.

The Research is carried out with the following Objectives:1. To review the condition of selected new build green housing projects in terms of the physical character, concepts and strategies used to lower the household energy consumption and highlight the best practicing materials for the wall element.

2. To examine different chosen materials for achieving energy efficiency and thermal comfort in the retrofit building.

3. To examine the various materials for their embodied energy embodied carbon, thermal conductivity, density and the distance it has to travel from cradle to gate.

4. To analyze the materials with respect to their embodied energy embodied carbon, thermal conductivity, density and distance from the retrofit site to consider for the retrofit building in terms of overall lifecycle energy analysis.

5. To create a basis for further research to improve the building fabric and reduce the overall energy in use of the building.

Assessment of the available materials for external fabric is done in terms of energy and thermal performance. The comparison of different materials is done to identify the correct combination for the retrofit of the house. These results are achieved through careful simulation of the existing apartment done using Design Builder energy simulation software.

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CHAPTER 2 - Research Methodology 2.1 - Research process through Diagram Background the existing energy efficiency and power sector in India and Tamil Nadu.

Identify the standards in India, IGBC - LEED Green homes rating system

Critical analysis of standards describing what is missing in it.

Research the existing new build green housing projects in warm humid & moderate climate of India to document the design features, materials, facilities and the ways of achieving internal comfort through efficient systems and technologies.

Create a building materials table showing various materials under structural, non-structural and insulation categories.

Analysis of these materials is carried out with factors of Low/medium/high. Preferred choices are shown at the end of the table.

To choose a housing project that could be retrofitted for energy efficiency and thermal comfort.

To simulate just the wall element of the building for the base case scenario results in Design builder energy simulation software.

To find out the existing energy and thermal comfort levels through the energy simulation and understand what could be done to improve it.

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Apply the relevant materials on the retrofit building which are considered from the material study table or the case studies.

The chosen material is applied individually to the wall element and a calculation is performed to find the exact embodied energy of that material based on its weight.

The findings enable a choice of best performing material for the wall assembly out of the shortlisted materials for its less embodied energy and achieve energy efficiency in the building.

The simulation process is carried out with the material combinations to see what results are best for the building being an improved retrofitted space for different lifecycles.

2.2 - Literature Review - To refine the process The research primarily depends on the type of data that is collected from the journals, reports, research papers, websites and people. The type of data needed includes Green building standards in India for a Retrofit home, the Project details of some of the energy efficient residential buildings, the concepts and strategies that led to the energy savings including type of materials used, availability of the material, application of the material (exterior walls and roof), and type of renewable strategies adopted to support energy efficiency.

How is the Data Collected?

One of the challenging and time consuming aspects of the research is the data collection. The research is linked with a geographical location (India). Much of the required data regarding the projects had to come from India. Several people were involved in the data collection through emails, video calls, phone calls, direct request of information through a third person (family members or friends).

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2.3 - Identifying factors to analyze and why The research process has to be further analyzed to investigate key aspects that have major role in determining the effectiveness of the research. The factors include:-, 

Transportation - A lot of energy is needed and used in the transportation of building materials from cradle to gate. This is because of the poor material selection criteria and lack of will by developers to choose a better environmental material nearer to the construction site.



Typologies of material - For simplicity, the building materials have been categorized according to whether they are structural/non-structural and insulation. The density factor of a material also has a crucial role to play in determining the amount of embodied energy transmitted by it.



Roof assembly - This is an important portion as it determines the thermal comfort, air penetration, insulation to the space and water proofing.



Wall assembly - This is an important typology to analyze in a building for determining various results such as performance of the building skeleton, thermal conductivity, air tightness, moisture penetration and thermal comfort of the space.

2.4 - Establishing embodied energy/carbon data/ substitution of materials The above factors mentioned are important criteria in a building that need to be focused on and form the essence of the building. All these factors are related to building materials which need to be carefully selected keeping in mind few criteria such as the embodied energy, embodied carbon and their substitution in the building itself. These criteria help to enhance the quality of selection process of these materials. Embodied energy and carbon determine the amount of energy that is burned during the manufacture process, sourcing, packaging, transporting to the project site (Miller, 2001). Hence these criteria helped to determine the choice of building materials to be adapted to the retrofit site.

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2.5 - Introduction to simulation and analysis The Aim of this study through environmental simulation is to determine the current indoor operative temperature, humidity levels, and the electrical consumption levels of the second floor of the apartment. The existing floor plan had been discussed above shows the building orientation and the space arrangement. A building in Chennai (warm and humid climate) is taken to convert in to an energy efficient structure through the careful alteration of materials to its exterior walls and the roof.

2.5.1 - Design Builder Design builder is simulation software that is selected for the research. Ecotect software is not considered as it does not give as accurate thermal results as Design builder. The modeling of the building is a quick process. It has a realistic user friendly interface that provides quick clear results. The software provides good outputs for thermal comfort, temperature differences, natural ventilation and CFD calculations. The output accuracy depends on the amount of input provided. The software is linked to Energyplus software as it gives the weather data required for the project. Quick difference in the results is compared for further analysis and improvement in design builder. The material library consists of several materials that could be applied to the building. The materials that are needed were readily available within Design Builder that makes the process more efficient.

2.5.2 - Method of Simulation The building is simulated for the existing base case scenario through initial modeling. The simulation is done to analyze the electricity consumptions through walls in kWh. The building materials are then changed for the walls with several combinations to check for the optimum result. Four different material simulations including the base case are performed. The materials to be substituted are carefully chosen based on the literature study. The chosen materials are tabulated in terms of walls, roofs, cladding/ non-structural materials and insulation materials out of which only the wall materials are simulated and analyzed. The comparisons of the

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simulations are displayed in tables for easy understanding. The method for analysis is as follows:-, 1. Four simulations including the base case scenarios are performed in Design builder.

2. Four different materials for walls would be applied and analyzed for the percentage amount of embodied energy of the material against the total energy in use.

3. The jpeg images of the results for those materials that the software produces are saved separately in order to compare them with other scenarios easily.

4. Several values and factors are considered from the material table (Appendices table 1.0), such as the embodied energy, density and thermal conductivity to calculate the amount of embodied energy of the specific material according to its weight.

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CHAPTER 3 - LITERATURE REVIEW 3.1 - Power Sector in India

Figure 5: Power Plant Utilization Improvements Source: Central Electricity Authority, India

The Power sector in India faces severe challenges with large power shortages, financially crippled electrical companies and inadequate access coverage. The government policy reforms in recent decades gave higher priority to the above challenges than to improve energy efficiency. India's electricity generation is mostly coal which is inefficient that constitutes 53% of total generation capacity with several measures been taken to improve the efficiency of these coal manufacturing units. Several renovation and modernization schemes have led to an improvement in the plant load factor (PLF) of the Thermal power plants that rose to 77% in 2006-07 from 63% in the 1995-96 periods (Central Electricity Authority, CEA, 2009) (fig 5).

Furthermore a table shows the dominance of coal under the installed capacity in MW for India.

Renewable energy sources contribute a mere 7% of the total generation of electricity in the country, although an improvement from 2007 to 2010 is seen on the rise which is a good sign for the years to come for India (fig 6). Having seen the importance of tapping energy efficiency through Retrofit statistics and the current state of power generation in India, the research focuses only on the existing Apartment buildings in the city of Chennai, India due to the limited time of the research.

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Figure 6: Power generation in India Source: http://expert-eyes.org/power/capacity.html

How important is it for India to focus on the Retrofit of Existing buildings to make them more energy efficient?

3.1.1 - Electricity use of India Electricity is the most used household fuel in the Urban India as it depends on the occupant's capacity with respect to income and the high price of the fuel. Over half the electricity consumed in India 2004-05, serves the top 20 percent of the population where most of the appliances are powered by electricity (fig 7). It is for seen in future as a natural consequence of the development in the increase of Per Capita electricity consumption with the decrease in poverty. The growth potential is high if the government initiatives on energy efficiency are implemented to reduce the overall electricity intensity of the household electricity use.

Figure 7: Distribution of electricity consumption by income class Source: National sample survey data, 2004-05

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It is clearly evident for India, Decrease in Poverty

=

Rise in household electricity consumption

Leads to Increase in electricity demand with already struggling power generation sector in the country with shortage of supply.

There is a need for clean energy and energy conservation through Retrofit of the existing buildings and promotion of the new green efficient buildings. simultaneously.

Under the current situation, India will be unable to supply the expected energy demand by 2030. The demand is created by the new constructions, the increase in connected load and consumption can be reduced by accelerating the building efficiency (ASCI, NRDC, 2011).

3.1.2 - Tamil Nadu - Profile for Energy Efficiency Tamil Nadu is one of the country's most urbanized state and the fourth largest contributor to India's GDP (Rediff Business, 2011). Chennai being the Capital of Tamil Nadu is India's fifth most populous city and the second largest exporter of IT, Software and ITES, after Bangalore. The city is under severe power shortage and there are no existing buildings that are retrofitted in the country (IGBC, 2012).

3.2 - Background on Retrofit Scenario in India Most old buildings could be converted to smart buildings and save energy with little capital investment that pays itself later. An interesting statistic according to the Indian green building council that says, there are several buildings 'green' that are registered under the certified status, but "about 99% of its new construction" when compared to the U.S, where retrofits exceeded new green building construction during December 2011 (Anand, 2012). The concept of constructing new buildings is well established while retrofitting of existing buildings is still a new concept that could improve the building components, operating systems and equipment,

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and installing energy efficient appliances. Retrofitting emerges as choice compared to re development to improve the economic life of old buildings (DECCAN HERALD, 2012). While the high standards of green building construction are shown by passivhaus (Germany), Minergie (Switzerland) and the zero carbon hubs (UK), the key to progress is the green building retrofitting of the existing conventional housing stock. A collective decision making is required for multi dwelling homes (Apartments) to consider for green building refurbishment poses a challenge (ILO, 2011). Many buildings are registered under the IGBC; the case studies that are shown below are also registered certified buildings to the IGBC. Hence IGBC green homes rating is followed for the research.

3.3 - IGBC Green Homes Certification Levels The LEED India green homes standards give us clear indication of the minimum requirements needed to get awarded green building status. In relation to the materials, the mandatory standards are only focussed on the 'U' values of the wall and roof assemblies, window glazing and shading and do not include any measurements of embodied energy and embodied carbon.

These two important parameters havent been given consideration or discussed in the detailed report of the green homes standards. There are no specifics about the way to bring down the 'U' value, no recommendations regarding the need for the usage of low embodied energy materials. Under the local materials category, the standards prescribe for atleast 50% of building materials used in building should have been manufactured within a radius of 500km.

The standards demand calculations demonstrating that the project uses the required percentage of local materials in terms of cost (IGBC, 2009). However:-, 

The density of the materials is not considered in the selection process



They only mention the manufacturers, but what about the source of raw materials?



what about the embodied energy used in transportation of these materials to the manufacturing unit and later to the site



The typology of materials that will be preferred if they were local is not discussed.

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The checklist for green homes with mandatory requirements to certify residential projects in India are given in the (appendix page 81-82). The checklist is used to evaluate all the points under the system to determine the level of certification that could be achieved by the building.

3.3.1 - Low carbon building example When there are no Co2 emissions from the operation including space heating, water heating, and lighting a home is considered as zero carbon building. Extraction, processing, manufacture and transportation of materials that constitute the building have significant carbon and energy implications which are known as embodied carbon emissions and energy. Embodied energy constitutes a high proportion of the whole-life of building in the current research of energy and carbon emissions. A study of a residential building (Crawford, 2013) shows the total energy of building for lifecycle of 50 years where, the operational energy was 40%, the initial embodied energy 37% and recurring embodied energy 22% of energy per lifecycle. Embodied energy and carbon are important parameters for low energy buildings that are largely influenced by the selection of materials and construction technologies. In the UK, Hammond and Jones had studied 14 cases of residential buildings and reported an average of 5.3GJ/m2 embodied energy and 403kgco2/m2 embodied carbon (Daniela Sahagun, 2011). The embodied carbon of all the properties studied is shown in (fig 8). It is observed that materials-constitute to 95% of the total embodied costs. The property with highest embodied loads is pilot 13 with 1.5 tonnes of embodied carbon whereas pilot 1 has 0.4 ton Co2. The databases of construction materials need to be extended and accurate information from manufacturers is needed. The results of this paper show that retrofit has great potential in lowering the whole life energy use and carbon emissions of buildings.

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Figure 8: Embodied carbon of the pilot study Source: (Daniela Sahagun, 2011)

3.4 - Climate of India and Tamil Nadu India has a tropical monsoon climate that refers to seasonal reversal winds during the course of the year. India is a vast country with different climatic zones namely Hot-dry, Hot-humid, composite, Temperate and cold respectively (fig 9). The region under the research falls under the Hot-humid climate category. India lies between the altitude of 8oN and 37oN with the tropic of cancer passing through the middle of the country dividing the southern part as torrid zone and the northern part as the temperature zone. The temperature decreases witht he increase in the height. Mountanous places are cooler than the plains (Facts About India, 2012).

Figure 9: Climate zone map of India Source: National Building code, 2005

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Warm and Humid Climate of India High relative humidity around 70-90%, glare from the sky and horizon, strong sun and high precipitation levels of 1200mm per year characterize this climate. Heavy rain is received in the monsoon periods. The breezes in the coastal areas can cause discomfort considerably. The temperatures vary between 20-30oC in the winters and 25-35oC during the summers (fig 10).

The building design should look to provide maximum shading, encourage cross ventilation and the dissipation of the humidity is required to increase comfort levels within the spaces (HPCB, 2012). The choice of building materials should be appropriate to this climate.

Figure 10: Average temperature graph of Chennai, India Source: http://www.chennai.climatemps.com/

The average temperature of Chennai reaches 28.6oC (86oF) with the maximum temperatures reaching 38oC (100oF) in the month of may (fig 11).

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Figure 11: Region of Tamil Nadu, India Source: http://revolutionaryfrontlines.wordpress.com/2010/03/26/campaign-against-green-hunt- launched-intamil-nadu/ climate/diversity/india/index.html

3.5 - Apartments in Chennai, Tamil Nadu Chennai is expanding with 7000 units added annually with 95% of them promoted them in suburbs due to the unmatched costs within the core city area. The city faces a shortage of one lakh units and could reach up to eight lakh units in the next 15 years with 50% of these housing development is under the affordable housing. The primary reason of the demand for apartment buyers is the lack of supply for affordable houses. Affordability is the biggest factor for the buyers (Indian Realty News, 2012) and is a factor in selecting materials for retrofit.

3.5.1 - Benefits from Retrofitting: A green retrofit involves an upgrade of whole or partial of building to improve its comfort, energy efficiency, water use and environmental performance to financially benefit the occupant/ owner according to the U.S Green building council (USGBC) (fig 12). Some of the benefits could be classified as:-,  Financially, cheaper than complete re-development with respect to major retrofit.  Opportunity to generate income out of the property as opposed to losing 4-5 yrs of rental income if newly developed.  Retrofitting avoids wastes through demolition and embodied energy within it.  Impact on energy efficiency and water usage leads to operational savings with less maintenance.  Retrofitting can improve value of property.

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ď&#x192;&#x2DC; Improved occupier comfort and future-proofing to anticipate tenant demand. ď&#x192;&#x2DC; Decreased energy costs for residents and also decreased CO2 consumption and usage of fossil fuels (Mellor, 2011) ď&#x192;&#x2DC; The occupants health and comfort can be improved

Figure 12: Life cycle phases of buildings Source: Graham, 2003

3.5.2 - Small Reduction Saving Opportunities: The Buildings sector that is spread across millions of small individual buildings that have multiple diverse energy needs creates many small scale reduction opportunities. Experts for this reason have referred these projects as "long tail" energy efficiency projects - to achieve large emission reductions at the top end of range of buildings per unit is relatively easy but as the size of the building gets smaller it becomes increasingly difficult (fig 13). The aggregate savings from "long tail" projects are to exceed the savings from the top end buildings due to the presence of large number of small buildings (UNEP SBCI, 2011). This is directly related to this research as the building considered for retrofit under chapter 6 is a small building. The choice of materials can make a huge difference here in terms of embodied energy.

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Figure 13: Small savings from large numbers of end-use units Source: Hinostroza et al., 2007, in UNEP, 2008.

In summary, the literature shows the power crisis in India, the lack of power generation from renewable sources, the demand vs supply gaps and the need for retrofit of existing buildings. It demonstrates the state of retrofit scenario in India and the kind of standards exist that do not consider embodied energy of materials. The studies from researchers show the importance of embodied energy and its contribution towards overall lifecycle of building. The benefits from retrofitting a small building is highlighted to benefit the larger section of population who are middle class living in small housing units.

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CHAPTER 4 - BUILDING CONSTRUCTION MATERIALS & EMBODIED ENERGY 4.1 - Green Building Materials A variety of strategies during design are integrated in sustainable building with construction and operation. An important strategy is the use of green building materials in the design of a building. The largest Co2 savings potential of all energy efficiency improvement measures is offered by building insulation (Saint Gobain, 2011). The transfer of heat to the building skin is slow with the preferred material reducing the need for heating or cooling. The introduction of LEED rating in India has led to new energy efficient equipment for local production that helps in reducing the manufacturing costs of the green building materials such as High performance glass, High albedo roofing materials, fly ash bricks for walls, waterless urinals, roof insulation materials and high coefficient of performance chillers (Dr Fixit Institute, 2010).

4.2 - Life of a construction material The life of a construction material from extraction to demolition with its re-use is seen in the (fig 14).

Figure 14: The cycle of materials Source - (Berge, 2009)

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The lifespan of a material can be determined by few climatic parameters that affect its durability such as solar radiation, temperature, air pressure, humidity, chemicals, wind and rainfall. Recycling products can reduce the resource and pollution footprint of a material. From the perspective of industrial ecology, the goal is to circulate all resources including waste within the human economic system, so that the final discarded waste and extraction of new raw materials become the absolute minimum. The different levels of re-use are:-, 

Reduce use of material in first place



Re-use



Material recycling



Energy recovery

A component that is used for a similar function in a largely unchanged form as a whole is known as re-use, an example being a brick reused as a brick. A good example of a building method geared for reuse log construction (fig 15). The Re-usable structures use primary and secondary monomaterials. A single homogeneous material used in its natural state such as untreated wood is known as primary and a mixed material of homogeneous nature such as concrete, glass or cellulose fiber is known as secondary monomaterial. Such materials are easy to check their quality for re-use (Berge, 2009).

Figure 15: Log construction Source - (Berge, 2009)

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4.3 - Materials selection Many important raw materials are at risk of exhaustion such as mineral ores and fossil oils.

Sustainable materials that are renewable need to be encouraged in building construction such as compressed earth blocks as a construction material, use of timber from deciduous trees, and several products from industrial waste, agriculture such as flyash, straw, and waste glass that are available near the case study retrofit site in India (refer appendices table 1.0). The use of stone has low embodied energy and is available locally. This reduces the embodied energy in transportation (refer appendices table 1.0). Many non-renewables have renewable alternatives such as the use of timber instead of steel and production of plastics from plants instead of fossil hydrocarbons (Berge, 2009). The use of timber products that come from managed forests and certified third party agencies, bamboo, cork, wool and straw are renewable materials (refer appendices table 1.0) that regenerate on a sustainable yield basis every ten years (WBDG, 2012).

4.4 - Embodied energy in Building materials/transportation The energy consumed in acquiring and transforming the raw materials in to finished products and transporting to the site is termed embodied energy in building materials (Miller, 2001). The estimated costs for energy in the manufacture of building materials are based on energy intensity which is a mix of thermal and electrical costs. On this basis the materials are categorized in to high, medium and low energy (fig 16). The type of materials that consume the most and least embodied energy are shown in the (fig 17) including the costs involved in the transport energy in India (fig 18) (ICAEN, 2004).

Figure 16: Classification of materials as per energy intensity Source: (ICAEN, 2004)

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Figure 17: Comparative energy requirements for various building materials Source: (ICAEN, 2004)

Figure 18: Transport energy costs for India Source: (ICAEN, 2004)

The construction industry has witnessed large quantities of manufacturing and consumption in India. The total energy expenditure on the energy intensive materials like Bricks, steel, aluminium and cement is 1684x106 GJ per annum. The environment is adversely affected by the extensive use of these materials draining the energy resources (ICAEN, 2004). A reinforced 33

concrete framed structure is commonly used for multi-storeyed buildings in urban areas consumes the highest amount of energy at 4.21 GJ per m2 whereas a load bearing two storeyed brick building is 2.92 GJ/m2. Sustainable alternatives which could be substituted to the retrofit site include:-, 1. The use of flyash/ blast furnace slag concrete that has 25% - 50% of less cement and up to 70% less when used for massive walls providing an excellent finish to the building (Reddy, 2004) 2. Stabilized mud blocks (SMB) which are more efficient, energy saving of 70% compared to burnt bricks that have 10% of cement content, 20% - 40% costs savings, elimination of plastering and aesthetically pleasing.

3. Steam cured blocks is a mixture of 6% lime, (25% flyash or black cotton soil - which ever available near the manufacturing place), 2% cement and sand to produce high quality blocks with wet compressive strength of above 6 Mpa which is enough to construct 3-4 storeyed load bearing building with 3-4m wide spans. These blocks are much higher in quality compared to local burnt bricks and stabilized mud blocks.

4. The use of recycled aggregates such as crushed concrete, glass, brick or other masonry wastes in conventional mixes and use of lightweight concrete (ICAEN, 2004).

5. Compressed stabilized earth blocks (CSEB) - These are blocks made of raw earth with Portland cement and lime used as earth binders for 4-10% of soil dry weight. The carbon emitted by blocks is: 

CSEB bricks

- 22kg Co2/tonne



Concrete blocks

- 143kg Co2/tonne



Clay fired bricks

- 200kg Co2/tonne



Aerated concrete blocks

- 280-375 kg Co2/tonne

The thermal conductivity and embodied energy of CSEB is: 

Lime based CSEB

- 0.2545 Wm-1k-1



Cement based CSEB

- 0.2612 Wm-1k-1



Clay fired bricks

- 0.4007 Wm-1k-1

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Low thermal conductivity for CSEB results in energy efficiency, cooling in summer, heating in winter and an environmentally friendly building. CSEB are greener, comparable in strength, durability and thermal conductivity (Fetra Venny Riza, 2011). The embodied energy of CSEB bricks is 0.275 Mj/kg (GRIHA, 2012).

6. Fly Ash Bricks The construction costs could be reduced over the use of alternate building materials such as flyash, which is a by-product from industries like thermal power plants (C Freeda Christy, 2011).

The embodied energy of flyash brick is 0.632 Mj/kg (Pierre Roux, 2011). The chemical composition and process is explained in the appendices, although a diagrammatic representation is shown below (fig 19),

Figure 19: Diagrammatic representative of flyash brick manufacturing process Source: (C Freeda Christy, 2011)

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Developing countries face energy demand for housing and other sectors. The use of flyash in the manufacturing process of conventional building materials has achieved energy savings (fig 23).

Figure 20: Energy savings achieved through Flyash Brick over other materials Source: (C Freeda Christy, 2011)

The other advantages of flyash are, 1. Emission of greenhouse gases and air pollutants is avoided at brick plants 2. Meets the IS standard, has appealing colors and is easier for laying the brick than the conventional bricks.

3. Compressive strength higher by 40% to 80% 4. Less heavy by 10%.

5. 20% less expensive than the conventional brick manufacture 6. Good demand could be created if the awareness among people is created.

A journal paper focused on a structure comparing between fire clay bricks and ash blocks. The test results, figures and the evidence of ash blocks performing better is provided (refer Appendices p76-80 for table 1 - table 8) (Ashok Kumar, 2012).

A major factor in the cost and energy of a building is the transportation of materials. Trucks are used in India to transport bulk of building materials. In urban areas, the materials travel 36

between 10km - 100km. Cement and steel take longer distances increasing the embodied energy. The transportation of bricks accounts towards 4 - 8% its energy in production for 50100km (K.S. Jagadish, 2003). A simple method to reduce this is by fixing the distance radius within which the materials have to be purchased (fig 21). For example, BedZed (Beddington zero energy development) used local sourcing with a 56km as radius. They saved nearly 120 tonnes of Co2 emissions or about 2% of the total embodied Co2 of the project (ICAEN, 2004).

Figure 21: Embodied energy involved in transportation of building materials in India Source: (Reddy, 2004)

4.5 - Analysis/Substitution of building materials for the retrofit case study A comparative material study has been done (Refer Appendix table 1.0 (Geoff Hammond, 2008) which lists out different types of materials in relation to various factors whether the material is preferred or not preferred for the retrofit case study in terms of five factors. These five factors are analyzed individually in the proposed table. The analysis is of the preferred materials and their possible substitutions on the retrofit case study were determined by: 1. The building materials needed to have less embodied energy below 3mJ/kg - low, 3 - 8mJ/kg medium and above 8mJ/kg - high.

2. The building materials needed to have less embodied carbon below 0 - 0.2 kgco2/kg as low, 0.2 - 0.5 kgco2/kg as medium and above 0.5kgco2/kg as high.

2. The availability of the material locally near the retrofit site to reduce the transportation costs and its embodied energy. The average distance radius from the source to the retrofit site is

37

fixed at 200-400km for all the materials. Below 200km - low, 200 to 350km - medium and above 350km is considered high.

3. The heat transfer across various materials with a low thermal conductivity that insulates to improve inner comfort and decrease the HVAC load in the building. The values are analyzed when, below 0 - 0.5 Wm-1k-1 as low, 0.5 - 1.5 Wm-1k-1 as medium and above 1.5 Wm-1k-1 as high.

4. The spreadsheet analysis has few factors involved in the consideration of materials. Each category for a material has an analysis of low/medium/high. Apart from the density factor, the other four factors are preferred to be low. Density is the weight of the material and how closely the molecules are packed in that material, below 1500/kgm-3 is low, 1500 - 1999/kgm-3 is medium and above 2000/kgm-3 is high. The considered materials from the spreadsheet analysis are discussed below.

Structurally, materials such as compressed stabilized earth blocks, flyash bricks and concrete blocks are preferred for building walls. Materials such as Portland cement with 50% flyash as the preferred cement, steel for structural strength, river sand from quarry for concrete mix, stone/ gravel for the concrete purpose and concrete mix with 25% or 50% flyash (table 1.0 appendix).

For cladding, gypsum plaster for wall plastering, slate, limestone and stone for wall cladding, timber, particle board and plywood for window frames, doors and interiors as it is a renewable material and glass for windows are the preferred materials. Under the category of insulation, materials such as cork, cellulose fiber, Vermiculite (expanded), gypsum plaster board, straw board and vermiculite (natural) are the preferred choices after careful analysis with five factors in the spreadsheet (table 1.0 appendix). A table of the chosen materials under different category is provided for clear understanding (fig 22).

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Figure 22: Chosen materials for the retrofit Source: From table 1.0, Appendices

When the building materials are given a thickness, we derive at the U & R values. The significant relationship of these material properties is, ď&#x201A;ˇ

Lower the embodied energy & carbon leads to a lower U-value (preferred)

ď&#x201A;ˇ

Lower the thermal conductivity leads to a higher R-value (preferred)

As the thickness of a material is increased, the U-value reduces and R-value increases for the entire wall or roof assemblies. The desired amount of thickness is needed for an optimum comfort indoor temperature. The simultaneous simulation process with these preferred materials determine the right amount of thickness that is needed to ensure a quality indoor space. An example of flyash brick wall assembly giving a U-value of 0.716 and R-value of 1.40 is shown below (fig 23). Such wall and floor assemblies can be created to simulate the building.

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Figure 23: wall assembly of flyash bricks Source - Mahindra Life spaces

Similarly different types of materials with alternate combinations will be pursued during the simulation process using Design Builder to achieve the lowest U-value. This process ensures a low embodied energy wall assembly with high thermal resistivity in a sustainable manner using the (Appendices table 1.0) as reference. The case studies follow next.

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CHAPTER 5 - CASE STUDIES The research focuses on the new build green residential buildings to capture the strategies used to achieve the energy efficiency that could later be adapted to the existing building based on the specific situation due to non existence of retrofit projects. The case studies include, 1. SHEMPARK by YUGA HOMES, CHENNAI (Chennai's first and the India's second Apartment building to be certified LEED Gold, 2010) 2. BCIL TZED HOMES by SPACE MATRIX, Bangalore (India's first LEED Platinum rated group housing project that comprises of Residential and Apartment buildings which won the Core Net Global Innovator's Award H BRUCE RUSSELL).

3. VIKAS APARTMENTS by AUROVILLE, puducherry, 1999 (A Housing complex that boasts several Apartments that are energy and water efficient) Each of these buildings has achieved something that makes a difference to the society.

5.1 - SHEMPARK APARTMENTS Shempark by Yuga Homes is the first completed apartment project in warm humid climate region of India. Simple concepts were implemented in the project to achieve the status of Green building. The tangible benefits achieved in the project are the 30% energy savings and the operational savings from day one of the project (FERNANDES, 2011).

Location Project location: 156, nukkampalayam road, Kumaran nagar, Chennai - 119 (Fig 24).

Site orientation: North facing plot (fig 25) Building orientation: The longitudinal portion of building is In the East -west direction while The windows and other openings in North-south direction.

Figure 24: Route Map to Shempark Source: www.yugahomesindia.com

Date of the project : 2010

41

Size of the project The Apartment consists of two blocks with 60 units in all ranging from 900 - 1200 sqft of individual units.

Typology of the project The project is classified as group housing with two Residential building apartments.

Floor plans (fig 25 & fig 26)

Figure 25: The figure showing the typical floor plan of the Apartment complex Source: http://www.yugahomesindia.com/shempark_floorplan.php

Figure 26: Apartment unit A, Shempark Source: http://www.yugahomesindia.com/images/ShemPark_FlatA.jpg

42

Elevations/perspectives (fig 27 & fig 28)

Figure 27: 3d perspective view of shempark Apartments Source: www.yugahomesindia.com

Aim of the project To achieve a green building standard of LEED Gold rating and to increase the awareness of green homes in the region.

Standards applied LEED India, IGBC green homes certification system.

Figure 28: Passive Solar design, elevation treatment

43

Materials used in project 

High albedo coating on roof that reflects over 85% of sunlight absorbing far less heat than conventional roofs (fig 29)



Walls made of fly ash brick with thermal conductivity that is 35 to 40% less than that of conventional brick walls – which allows less heat into the interiors



Solar water heaters in the terrace area (Fig 30)



75% of the procured materials for the project are less than 500km from the project site.



Over 20% recycled content in building materials, for example: Fly ash bricks – 50%, steel - 60%, Glass - 20% and Tiles - 24%

Figure 29: Roof Coating at Shempark

Figure 30: Solar water heaters at Shempark

Many material considerations and options have been explored by the consultants to maintain the comfort level of the occupants below the Roof. Two different types of choices had been considered such as

44

OPEN TO SKY

  HERMATEK (heat reflective  coating) + Roofing tile + Filler  material + broken waste bricks for  4" of thick + water proofing layer.   EXISTING RCC ROOF     (Chosen Combination)

OPEN TO SKY

Heat reflective tiles + Screed + XPS Polyestuerene material + water proofing layer.

EXISTING RCC ROOF

(Left out Combination)

5.2 - BCIL TZED HOMES This project has a new sensibility that addresses wider concerns of energy use, sustainable urbanism and ecological awareness. The residents pay 30% less for energy and 20% less on monthly maintenance due to the first centrally air-conditioned residential campus with no CFC and HCFC and zero electricity Refrigerators. Solar passive architecture and environmentally friendly materials are used to reduce thermal loads of air - conditioning with enhancement in daylight (ANUP NAIK, 2011). Further details about the project are as follows.

Location - Bangalore, India (fig 31)

Figure 31: Map to go to TZED

Date of the building - 2011, completion of the project Size of the project TZED, a five-acre housing development in Bangalore incorporates many sustainable factors of design. The project has 80 apartments, 15 houses and clubhouse forming 2.5 million sq ft of built up area.

45

Typology of the project Gated community Apartments and Individual homes Floor plans (fig 32) & (fig 33)

Figure 32: Apartment type - 1, BCIL TZED

Figure 33: Apartment type - 2, BCIL TZED

46

Elevations/perspectives - (Fig 34)

Figure 34: Apartment 1 & 2 - BCIL TZED

Aim of the project The project aims to prove sustainable living in the Indian Urban context is technically and economically viable for everyone with managing comfort.

Standards applied LEED India, IGBC green homes certification system. The project achieved LEED Platinum.

Materials used in project The primary criteria for the construction materials are the three (R's) - Reduce/Renew, recycle and reuse. The following aspects are considered for the selection of materials and systems. 

Regional sources - Stone flooring would be locally sourced



Lower embodied materials like natural stone floors or ceramic tiles considered instead of industrial vitrified tiles



High energy materials reduced such as cement/ steel with the slabs being non RCC



Recycled content where construction debris used to prepare PCC and for road layout and (SSB) soil stabilized blocks from the excavation of waste from the other sites.

47

Other materials include, 

Quarry dust used in the place of sand for PCC and Plastering work



Stone or Slate clad for washroom walls with surface treatment to make it water proof



Filler and Reinforced concrete combine to comprise the roof slabs



Walls with SSB's - Sundried compacted Bricks made of earth and crushed construction.



Lightweight fly ash bricks used for internal walls to reduce steel quantity for the roofs.



"Sky gardens" or Green roofs contribute to the thermal comfort of dwellings. Planting space for every home provided on roof serving thermal insulation for lower floors and adjoining spaces. The heavier soil is replaced by lightweight mulch with coir pith and irrigated via drip method.



The local resources used to reduce carbon emissions are Rubber wood for flooring and door shutters, palm wood for external walkway decking, compressed coir door panels for shutters, Bamboo composites for roofing of club and interior wood works.

5.3 - VIKAS APARTMENTS, AUROVILLE - by Satprem Maini (Architect) This project was the first development in Auroville, which used stabilized earth right from foundations to roof. To date, Vikas community still represents the most synthetic holistic development, which has been materialized in Auroville. The proper management of earth resources was always the first priority. The quarries where the soil was taken from were always planned first. This procedure allowed a perfect integration of the excavations with the buildings and landscape. The concept is to get an energy efficient building, natural ventilation with sun protection, integration to the land according to the existing nature, trees and adaptation to the climate with respect to the wind directions, etc (fig 35).

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Figure 35: Apartments 1 & 2, Vikas Source: www.earth-auroville.com/...pics/02-Vikas-community.pdf

Location Auroville village, Puducherry Date of the building Period of construction - (1992-1999) Size of the project The project had a total built up area of 1420 sq m Typology of the project Residential development - mixed dwellings including apartments and homes.

Floor plans (fig 36) The project was completed nearly 15 years ago; hence the individual floor plates of units were not available. The site layout of vikas apartments gives us the idea of the scale of development.

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Figure 36: Overall layout of vikas apartments Source: http://www.earth-auroville.com/maintenance/uploaded_pics/02-Vikas-community.pdf

Elevations/Section (Fig 37) and (Fig 38)

Figure 37: Elevation of the vikas apartment Source: http://www.earth-auroville.com/maintenance/uploaded_pics/02-Vikas-community.pdf

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Figure 38: Section of the apartment building, Vikas Source: http://www.earth-auroville.com/maintenance/uploaded_pics/02-Vikas-community.pdf

Aim of the project The concept of this building was such that it should be self-sufficient for its soil needs. The soil was dug from the basement floor (1.20m below the original ground level) to produce compressed stabilized earth blocks for building the structure of 819 m2, carpet area, on 4 floors.

Standards applied No standards were applied to this project as they were not developed at that period Materials used in project 

Compressed stabilized earth blocks of various qualities that has very less embodied energy and carbon (Refer Appendices table 1.0)



Various stabilized earth based materials



Ferro cement pieces in various parts of buildings

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Construction method The management of the earth resources was a priority where quarries for sand are planned.

Little soil was supplied from outside to the project for construction. 

Stabilized rammed earth foundations with 5 % cement



Plinths and walls in compressed stabilized earth blocks



Stabilized rammed earth walls with 5% cement



Composite beams and lintels and composite columns



Vaults and domes for floors and roof, made of CSEB



Floorings with CSEB tiles, 2.5cm thick with 5 % cement



Ferro cement channels of 25mm thickness



Ferro cement doors, shelves, etc. of 12mm thickness



Sparing use of concrete, glass, steel, etc.

5.4 - SUMMARY/ANALYSIS OF THE CASE STUDIES In summary, the three case studies presented good use of building materials. Shempark used flyash for walls with 20% recycled materials and broken bricks for roof cover which is innovative. BCIL used flyash for internal and soil blocks for external walls which is a clever way of material distribution. The use of wood and stone for flooring and joinery showed the depth of material study. Vikas apartments presented CSEB for all walls and earth used for paints and plastering is the most vernacular of the three case studies although, all studies shared common character using low energy materials. The analysis of the three case studies is shown (appendix p83-84).

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CHAPTER 6 - RETROFIT OF APARTMENT - A CASE STUDY 6.1 - Introduction of the existing project The Apartment project chosen for Retrofit is an old building named AVS GANESHA (fig 39) was constructed in 1997. It is a three storey structure with six apartment units altogether. First and Second floor layouts are typical. Over the years, the building has deteriorated in terms of its strength, water seepage, wall cracks, air tightness, broken tiles in the roof, etc. The second floor being the top floor, the residents had faced several problems regarding the overheating during the summer. The bedroom on the south east gets very hot during the summers as it is exposed to the sun from the roof and the exterior walls. The plan shows east facade is fully affected by the direct solar radiation which provides discomfort to the occupant (fig 40).

Figure 39: 3d view of the retrofit apartment Source: From the occupant

Location Chennai, India Date of the building Period of construction - (1995-1997) Size of the project

53

The project had a total built up area of 400 sq m Floor plans (Fig 40)

Figure 40: Typical Floor plan of the Retrofit Apartment Source: Koshy Associates, Chennai

Typology of the project Residential Apartment development 54

Aim of the project The aim of the project was to create maximum carpet area with comfortable spaces providing well enough lighting and shading to the project.

Standards applied No standards were applied to this project as they were not developed at that period Materials used in project 

The walls are 230mm thk clay fired bricks with 3mJ/kg as embodied energy with 12mm cement mortar on the either side of the exterior walls that has 1.33 mJ/kg as embodied energy (Refer table 1.0 appendices)



Interior walls are 115mm thk with 12mm cement mortar on either side of wall.



Exterior wall finish is with marble chips stuck to the plaster as an Aesthetical treatment that have an embodied energy of 2mJ/kg and 0.112 kgco2/kg as embodied carbon which is considered medium energy with a far distance to the site (Refer table 1.0 appendices)



The roof is a 150mm thk reinforced cement concrete that has higher embodied energy when compared to flyash substitution and roof tiles placed on 12mm thick cement mortar with 1.33 mJ/kg as embodied energy (Refer table 1.0 appendices)



The windows are single glazed with wooden frame and 300mm of shading device.



All these materials are analyzed for Embodied energy, embodied carbon, thermal conductivity, density and transportation distance from source to the site.

6.2 - Simulations in Design Builder The building is modeled in Design builder (fig 41). The inbuilt weather data is referenced from Energy plus is set to Madras (Chennai) as the project location. The heating set point is kept at 18oC while the cooling set point temperature is at 23 oC as generated by Energy Plus for the location. The space is preset for natural ventilation without the use of mechanical ventilation.

The clothing factors have to be considered at 0.5 (clo) during the summers and 1.0 (clo) during the winters. The occupancy density remains as default value in the design builder. The internal flooring and the partition walls remain the same for all scenarios. The target of 300 lux is given for lighting. The office equipment factor is left switched on as many electrical items require

55

power. The changes in the building wall assembly determine the exact amount of embodied energy difference between several materials. The computers are set to 'on' as they generate heat. All the simulations are performed over one year to know the energy in use of the building across all seasons. The results in (figure 42) can be compared for different wall materials to analyze their performance and these are then compared to the embodied energy performance.

Figure 41: Design Builder model of the Retrofit Apartment Source - Design Builder

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6.3 - Comparison of Embodied energy against energy in use for wall element The buildup of the total embodied energy and energy in use for each of the four materials is shown in figure 42 below. The buildup of each material and their energy in use values are shown in the (appendix p85-88).

Figure 42: Energy analysis of different wall materials Source: Design Builder

Where, M - Mass of the element (kg) is derived from: D - Density factor of the material (kg/m3) (Refer Appendices Table 1.0) EV - Element volume of material in the building (m3), where M = EV * D EE - Embodied energy of the material (Mj/kg) (Refer Appendices Table 1.0) EEEV - Embodied energy of the element volume of material in the building, where

57

EEEV = kWh/kg x kg/EV = kWh/m3 (This value multiplied by total volume gives EEEV) (Conversion factor of 3.6 is used to convert from Mj to kWh. The EEEV is calculated separately for wall and the mortar. It is then added up together to give EEEV for the entire wall assembly).

AE - The simulated result of the Operational annual energy in use of the building (Kwh) TE - The total overall energy involved in the building in the first year (Kwh), where TE = AE + EEEV %EE - Percentage of the embodied energy against energy in use for one year %EEEV = EEEV / AE * 100

6.4 - Analysis of material for % embodied energy against total energy in use

Figure 43: Embodied energy against energy in use over one year Source: From fig 42

As seen in the above graph, the clay brick being the base case has the highest amount of embodied energy while the compressed stabilized earth block has the least embodied energy against the energy in use (fig 43). Below are the graphs of each individual material with respect to the % embodied energy and the annual energy in use for one year (fig 44).

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Figure 44: % of EEEV compared to energy use of the building Source: From fig 42

6.5 - Analysis of difference in the energy use (AE) of different materials The retrofit building was simulated with four different material scenarios to identify the exact change in the annual energy use (kWh) of the building (fig 45) and (fig 46).

Figure 45: AE - operational energy of the building Source: From fig 42

Figure 46: Annual energy saving from the base case Source: From fig 42

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The AE is the energy required for space heating and cooling, lighting, cooking, hot water heating, refrigeration, appliance and equipment operation. The Thermal performance of the building through simulation is subject to limitations and assumptions as these programs are not yet capable of modeling complex human behavior. However, the buildings are evaluated for their thermal performance as simulations allow large numbers of variables to be modeled (Roger Fay, 2010).

The analysis of AE for different materials shows a significant reduction of energy in use by using CSEB bricks, flyash bricks and concrete blocks compared to the base case of clay bricks. The percentage of energy in use saving from the base case shows 16.52% for CSEB, 8.85% for flyash bricks and 11.65% for concrete blocks. The CSEB brick gave the highest amount of energy saving showing the importance of thermal properties of a material. The concrete blocks produced marginal savings in energy over the flyash bricks. In such scenarios, the distance of the source material, its availability and labour become the deciding factor on the choice of material itself.

6.6 - Analysis of materials for their availability, distance and skilled labour The distance of the source material from the retrofit site, its availability and skilled labour are more issues pertaining to the choice of the material. Embodied energies include the mode of transportation, the energy required to load the material on truck/train by the machinery in the manufacturing site and the energy emitted by the labour at the site to unload the material.

These energies are often difficult to estimate as it is complex, however:-, the embodied energy of transportation can be estimated from the literature (Cannon Design, 2012)(fig 47).

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Figure 47: Energies of various mode of transport Source: Cannon Design, 2012

For the four materials for the retrofit site the distances are 21km for clay bricks, 43km for flyash bricks, 21km for CSEB bricks and 482km for concrete blocks. Energy savings of CSEB bricks is much higher than flyash bricks on both counts as seen in EEEV and AE. The availability of material and labour for these materials is confirmed by the three earlier case studies presented in the research.

6.7 - Life expectancy of the materials The life expectancies of the materials and components associated to a residence depend on the weather, climatic conditions, quality of installation, and level of maintenance and the intensity of use. The changing styles and improvements of new products may encourage the occupant to change few components even though life expectancy of that product remains. On the other hand, the introduction of new technologies has also increased the life expectancy of some components during the last 35 years. Clay brick walls and concrete blocks used for exterior brick work have an average life expectancy of 100 or more years (National Association of Home Builders, 2007). The life expectancy of CSEB bricks is 100 yrs or more till the life time of the

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building (Instituto Tierra Y Cal, 2010). The Flyash bricks are a mixture of cement, flyash and lime. These bricks gain strength with time and get stronger for the future with a life expectancy also of 100 years (Ultimate Infra, 2011).

6.8 - Analysis of the material life & Summary of Energy retrofit It is observed from the literature; all the materials have the life expectancy of at least 100+ years. The life expectancy of the materials is therefore analyzed for 100 years to show the percentage difference between clay brick and the alternatives:-, (fig 48).

LE (%100yrs)

Clay Brick

CSEB brick

Flyash Brick

Concrete block

0.80%

0.136%

0.221%

0.214%

Figure 48: Embodied energy compared to energy in use of materials over 100 years Source: From fig 42

LE - Life expectancy to show % of embodied energy to the energy in use of building LE - %EEEV/ 100 The CSEB bricks gave the least 0.136% of energy per life cycle of the building.

In summary, this chapter followed various stages of energy calculations and analysis of the materials. The embodied energy (EEEV) of the wall element is calculated for each material. The retrofit building is simulated with different materials for the annual energy in use (A E) showing the percentage of energy saving for each case. The embodied energy is then compared to energy in use over one year and then over the complete built lifecycle. The CSEB bricks performed the best of all in terms of total energy use, being low in embodied energy and also low in heat gain/heat loss due to a relatively high insulation factor.

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CHAPTER 7 - DISCUSSION A number of themes can be extracted from the results in the previous chapter relating to other studies and other factors.

Comparison of results to other studies The EEEV of clay brick in this retrofit case study is significantly higher than the literature compared to other studies. A study done on the comparison of clay bricks and Ash blocks for a small structure in India shows 15,394Kwh & 6,655kWh of embodied energy against 57,753kWh & 23,890kWh of total energy in use over 20 years where the clay fired brick contributes to 26.65% and Ash block 27.85% of embodied energy against the total energy in use. However, the total energy in use saw a 58% energy saving for the Ash block against the clay fired brick (Ashok Kumar, 2012). A study suggests that alternative wall materials alone (without insulation) reduce the energy demand of the building by 5% and 10-30% energy savings when insulation is added to the wall and the roof. The analysis of embodied energy of different wall materials against the total energy in use resulted in 20.1% of embodied energy for clay brick, 13.63% for soil cement brick, 14.21% for flyash bricks and 14.07% for hollow concrete blocks of embodied energy against the total energy in use per year of the building (T.Ramesh, 2012). The alternate materials of CSEB, flyash brick and concrete blocks in the Chennai case study of retrofit considered in this study saw marginal high % embodied energy of 13.68%, 22.11% and 21.49% against the energy in use compared to other studies and significantly high % of embodied energy for clay brick (base case) when considered over one year. This can be partly attributed to a climate context differentiation within India as Chennai comes under warm-humid climate.

The findings (Ravi Prakash, 2010) show that 10-20% of total energy is accounted by the embodied energy of materials and the rest 80-90% of energy for the operation of the building per year. Though the embodied energy constitute to only 10-20%, the opportunity to reduce it further should not be ignored.

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The theoretical findings of the retrofit apartment through simulation presented the best performing material (CSEB) for the wall element considering the embodied energy and the annual energy in use of the building. However, the three earlier case studies presented in chapter 5 show a good use of materials from flyash bricks and CSEB for walls, filler slabs, NonRCC also for slabs, green roofs to reduce solar gains, the use of recycled materials and stone for flooring. These case studies did not highlight the importance of embodied energy of materials although they presented less energy intensive materials.

The research here has focused on the wall element although lot of other factors need to be accounted for an overall retrofit of the building such as ageing & cracking of materials, maintenance issues, people behavior, the usability of controls and occupant understanding of the low carbon technologies.

Material changes and failures Earth as a raw material for building is made of raw earth and clay where cracks occur over the lifecycle of the building. The water absorption ratio of such materials is weak compared to clay bricks that affect the strength of the building over time. Care needed to minimize these material changes over the lifecycle of the building. The occupants can alter their homes that affect the embodied energy calculations of the building over the lifecycle. Changes of materials and small element alterations in the building have an effect in the rising of embodied energy.

The maintenance of a building has an effect in the embodied energy which is recurring energy.

The data about the maintenance over the years is not available due to change in occupants and difficult to factor in this research.

User behavior, energy reduction and retrofit (Stevenson Fionn, 2013) Focus on reducing domestic energy in relation to occupant motivation, practices and behavior, building performance evaluation (BPE) that measures user's responses.

The communication to the user about the design intent is critical in understanding the function of building features and systems. Detailed widespread usability studies are required to understand the failure of low-carbon products and systems. (Gupta R, 2010) Show that there has been no critical analysis been undertaken to integrate the occupant feedback methods 64

before retrofitting existing housing (Pre-refurbishment). The need to change lifestyles and user behavior are identified as significant component of wasted energy and resources in retrofit. The current retrofit project (theoretical) deals with simulation values for energy in use, although in reality the real time electricity metered bills may vary vastly (practical). The occupant's feedback on any existing problems in reality gives the insight in to the suggestions on low carbon techniques and modeling that could be a win-win situation to the occupant and designer.

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CHAPTER 8 - CONCLUSION 8.1 - Summary of the Research Retrofitting existing homes is a cost-effective way to improve the energy efficiency rather building a new one. Many issues are looked at in the study including the income levels per capita leading to affordability issues of buying new homes at market prices and retrofitting is seen as an alternative. The literature review identifies the problems of the power sector, its shortages, demand v supply gap, 65% power generation through coal and only 7% via renewable sources causes a worry to the rising urban population who consume 53% of energy which is said to increase further due to rapid urbanization. The need for retrofitting existing homes to conserve energy became more evident along with new green homes. The methodology identifies a gap in the IGBC-LEED green homes rating system in relation to embodied energy. The traditional materials consume high energy in production whereas alternate materials can be manufactured with low embodied energy. The small reduction savings from small buildings is identified as large savings overall as there are large number of small housing units that led to the retrofit of a small building in this research. The study on the life of construction materials, their embodied energies, carbon and transportation shows the amount of energy being shed in the manufacture of these materials. This led to the study of alternate low embodied energy materials that could replace for all the elements of a building.

Three new build case studies are evaluated for the use of green materials, facilities and energy efficient systems, due to a lack of data on green retrofit in India. A table of materials is used (refer table 1.0, appendices) to identify the best choices of materials for each category. Four materials are analyzed in terms of embodied energy, embodied carbon, density and transportation for the selection of materials for the retrofit project. Simulated thermal analysis is then used to identify the annual energy in use of the building in relation to the manually calculated embodied energy. The findings from the analysis of materials showed that CSEB bricks performed as the best wall material overall to carry out retrofit of the building. The discussion covered wider and deeper aspects to be considered prior and post to a retrofit, such

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as material durability, maintenance, occupant behavior and understanding of systems and appliances that were the missing fields of the current research.

The cost of the retrofit may be a wider important question towards an overall retrofit that indirectly depends on the localization of building materials, embodied energy, machinery usage and transportation. The selection criteria of building materials need to be scrutinized for its physical and thermal properties evaluation in relation to embodied energy and costs. However, the durability and strength of the materials also need to be comparable to the accepted standards.

The findings from simulation of various materials showed an improvement of up to 16.52% in the energy savings (CSEB) from base case due to better thermal properties of the material. The modeling used by the software is complex to understand and questionable in relation to the real energy usage derived from a practical research, but it is the best we have and can be improved. The embodied energy methodology is also still not robust, but again, a start must be made as it is clear that it plays an important role, depending entirely on the lifespan of the retrofit

8.2 - Limitations of the Research The specific research of the retrofit building is that it carried out analysis only for the wall element and not other elements due to financial constraints of occupants. More materials should also be considered for a wider research in this case. The building is a specific study and more types of housing units should be considered to generalize the findings from this research.

8.3 - Further Research Retrofitting housing in India needs more awareness of the benefits and savings in energy related to embodied energy. A practical research including embodied energy questionnaires and energy bills from the occupant along with the energy simulation and embodied energy calculations could help the retrofit process to be more accurate and problem specific. There is a tremendous amount of scope here to conserve energy and improve the power crisis of India.

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Appendices

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75

76

77

78

79

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Check List for Green Homes Source: IGBC Green homes rating system 1.0 - Abridged reference guide - April 2009, page 18.

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Check List for Green Homes Source: IGBC Green homes rating system 1.0 - Abridged reference guide - April 2009, page 19.

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Analysis of the three case studies under the chapter 5, Summary

Project Brief

ShemPark Apartments

BCIL TZED Homes

Vikas Apartments

A LEED Gold project

A LEED platinum

Energy efficient

East-west oriented building with natural cross ventilation and excellent day lighting

Aims to develop energy efficient buildings with the use of local materials

Community of homes and apartments

Central courtyard that Building orientation channels the day light to is skewed to permit many apartments more natural light Elevation treatments act as sun shades

Energy Efficiency

Project addresses sustainable urbanism and ecological awareness

Low AC bills due to Centrally air reflective coating on the conditioned campus roofs. saves 30% electricity Energy efficient lighting with CFLs with automation sensors in all rooms and common spaces of apartment Solar water heaters in the terrace area for hot water.

Well designed building

Zero CFC and HCFC refrigerators

East-west orientation of longer side facades, natural ventilation Good use of building technologies Community participation to help energy efficiency

Solar chimneys integrated in to design Well designed over hangs cut off solar gains

Motion sensors and Solar water heaters light sensors installed and pv on the roof Solar water heaters, wind mills , solar water pumps installed

Terrace gardens and creepers on the west facade CFL lamps used for lighting

Generator backup

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Material Specifications

Flyash bricks used that has 35-40% less thermal conductivity allows less heat inside

Soil stabilized blocks for walls, local natural stone for flooring

Over 20% of materials used are recycled ones

Flyash bricks for internal walls

75% of materials procured less than 500km of distance

Quarry dust for PCC instead of sand

Broken waste bricks used as roof insulating material

Green roofs to reduce direct solar gains

E'Blocks used as brick walls and roofs AURAM 240 blocks used for vaults, roofs and domes Stabilized earth used for paints and plastering Ferro cement tanks, shelves, etc

Rubber wood for flooring, doors, etc.

Good choices

Flyash bricks

Flyash bricks

CSEB bricks

made in terms of

Waste bricks for insulation

Quarry dust for PCC

Ferro cement domes and roof construction

Segregation of waste at source level

Composting of kitchen waste

Waste generated is recycled

Composting of organic waste on the site

Vermi composting pits to convert to natural fertilizers

materials Waste management

Reflective paints on roof

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Clay Brick - Construction and energy use per year

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CSEB Brick - Construction and energy use per year

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Flyash Brick - Construction and energy use per year

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Concrete Blocks - Construction and energy use per year

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