CHAPTER 1 INTRODUCTION
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1. INTRODUCTION
1.1
THE GREEN CONCEPT
Green is not just a color today!
With rising energy costs, tightening budgets, increasing populations and
diminishing resources, it is becoming increasingly important that business and individuals conserve or ―go green‖
Green – or sustainable- building practices help to create healthier and
more resource – efficient models of:
-
Construction
-
Renovation
-
Operation
-
Maintenance
-
Demolition
Green symbolizes environment friendly practices in all facets of
human endeavor
1.2
WHAT IS A GREEN BUILDING? A green building depletes the natural resources to the minimum during
its construction and operation.
Main aim is to -
minimize the demand on non renewable resources
-
maximize the utilization efficiency of these resources, when in
use -
maximize the reuse, recycle and utilization of renewable
resources.
Optimizes the use of on-site resources sinks by bio-climatic architectural
practices.
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Uses efficient equipments to meet its lighting, air condition and other
needs
Use efficient waste and water management practices
Provides comfortable and hygienic indoor working conditions.
In sum, the following aspects of building design are looked into an
integrated way in a green building: -
Site planning
-
Building envelope design
-
Building system design (HVAC, heating , ventilation and air
conditioning, lighting, electrical and water heating) -
Integration of renewable energy resources to generate energy
on site. -
Water and waste management
-
Selection of ecologically sustainable materials(with high
recycled content, rapidly renewable resources with low emission potential, etc.) -
1.3
Indoor environmental quality
WHY MAKE A GREEN BUILDING ?
All over the world we are finally beginning to recognize the threat that building construction is posing to the civilization. Buildings have major environmental impacts over their life cycle. There are various problems arising in the present scenario: PROBLEM 1- BUILDINGS CONSUME:
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40% of all energy Figure 1.1 - Distribution of energy consumed by a conventional building
71% of all electricity
50% of all gas demand
12% of all fresh water
88% of all potable water
40% of all wood, steel and other raw materials
1 acre gets developed every 12 seconds!!! PROBLEM 2- BUILDING POLLUTE:
Building contribute 40-50% of green house gas (GHG) emissions
Building creates 65% of all solid waste, 90-95% of construction and
demolition waste could be recycled
Figure 1. 2 - A pie chart showing the percentage of construction waste obtained from various activities.
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Indoor pollution often 2-100 times worse than outdoors
PROBLEM 3- IMPACT OF ASIA ON GLOBAL WARMING In next 25 to 30 years
Energy consumption of developing Asian countries will more than
double
CO2 emissions will increase more than three fold
Electricity generation in asian countries is expected to make the greatest
contribution to CO2 emmisions -
APERC,2006
SOLUTION IS A GREEN SUSTAINABLE BUILDING
Energy efficiency is the most effective way to address climate change
Energy efficiency is the cheapest source of additional energy supply
and the most cost effective way to reduce GHG
An efficient sustainable building will : -
reduce energy usage and life cycle cost
-
create a better environment for occupants
-
reduce use of water and consumption of natural resources
-
reduce generation of pollution and CO2 emission.
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1.4 ECONOMIC BENEFITS PERCEPTION : Green buildings are costlier
REALITY :
Considerable research and analysis has been carried out with regards to the cost impacts of a green building. The cost could be slightly higher than conventional building. But then, this need to be seen in a different paradigm. The question is how do we compare the cost? There needs to be a baseline cost for all comparisons to be alike.
The incremental cost is always relative and depends on the extent of eco-friendly features already considered during design. The incremental cost would appear small if the baseline design is already at a certain level of good eco-design; It would appear huge if the base design has not considered green principals.
The second and rather critical paradigm is to look at the incremental cost in relation to the life cycle cost. This kind of an approach could be revealing. Who knows, a building would last for a 50 years or 60 years or 100 years! Over its life cycle, the operating cost would work out to 80-85 % while the incremental cost which is one-time cost is only about 8-10%
Building
Year
Built in area % increase in cost Payback
Constructed (sq.ft.) CII-Godrej GBC,
2003
(years)
20,000
18%
7
1,70,000
15%
6
2005
1,75,000
8%
5
2005
40,000
6%
3
Hyderabad ITC Green Center , 2004 Gurgaon Wipro, Gurgaon Grunfos Pumps,
6
Chennai Technopolis,
2006
72,000
6%
3
2007
15,000
8%
4
2007
78,000
2%
3
Kolkata Spectral services, Noida HITAM, Hyderabad Table 1.1 – Payback periods of Green buildings
There is a decreasing trend in the incremental cost over the years. This trend would continue and we all look forward to the day when the cost of green building will be lower than a conventional building.
Green buildings are well poised to grow in the years to come which would provide tremendous opportunities to all the stake holders.
The investment opportunities in green buildings is estimated to be about 2000 crores by the year 2008.
1.5 GREEN BUILDING MOVEMENT IN INDIA 80 70 60 50 40
LEED REGISTERED BUILDINGS
30 20 10 0 2002
2003
2004
2005
2006
2007
Figure 1.3 – Number of LEED registered buildings.
India is witnessing tremendous growth in infrastructure and construction development. The construction industry in India is one of the largest economic activities and is growing at an average rate of 9.5% as compared to the global average of 5%. As the 7
sector is growing rapidly, preserving the environment poses lot of challenge and at the same time presents opportunities. The construction sector therefore needs to play its role and contribute towards environmental responsibility.
The green building movement in India is a step in this direction-to minimize the negative impact of construction activity on the environment
The Green Building movement in India spearheaded b CII has gained tremendous impetus over the last six years. From a modest beginning of 20,000sq.ft of green building foot print in the year 2003, India is today witnessing atleast 20 million sq.ft of green building foot print with about 80 green buildings being constructed
The rapidity of the green building movement can be seen by the spiraling growth of clearly measurable green building criteria as indicated in the following table
No. Criteria
2001
Till date
1
CEOs & senior people involved
50
2000
2
No. of professionals trained on
10
2500
1
80
LEAD rating 3
No. of registered Green Buildings
4
Built in area (sq. ft.)
0
25 million
5
Green building products and
5
50
equipments Table 1.2 – Increasing green movement
1.6 GREEN CONCEPT IN INSTITUTIONAL BUILDING The green movement is gaining momentum rapidly. But, is the rate enough? And the answer is of course ‗NO‘. It certainly needs more and more people‘s involvement to get visible and desired result. One can‘t blame anyone for non-
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involvement if they aren‘t aware of green concept. Certainly, they need to know it to get involved. The key is awareness. To increase the awareness what would be a better place than an educational institution. Here thousands of students come every year. They stay, they learn, they grow here. It‘s the place to share new ideas and concepts. So if they get to see a live example of green initiative, they won‘t only know, but will be able to judge and see the benefits. They too may start thinking green and finding out new and better green ways. And then thousands of students go out every year to different places of their work field. They of course take their ideas with them and influence the people at their work place, which in turn further increasing the awareness. The idea is to increase the awareness at roots.
1.7 RATING SYSTEMS FOR GREEN BUILDINGS
1.7.1 LEED-US The United States Green Business Council (UGBC) has developed The Leadership in Energy and Environmental Design (LEED) Green Building Rating System, which is the internationally accepted benchmark for design, construction and operation of high performance green buildings. LEED gives Building owners and operators the tools they need to have an immediate and measurable impact on their building‘s performance. LEED promotes a whole building approach to sustainability by recognizing performance in 5 key areas of human and environmental health 1.
Sustainable site development
2.
Water savings
3.
Energy Efficiency
4.
Material selection
5.
Indoor Environmental Quality
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POINTS
Prerequisites
Mandatory
1. Sustainable site
13 points
2. Water efficiency
6 points
3. Energy and Atmosphere
17 points
4. Material and Resources
13 points
5. Indoor Environmental Quality
15 points
6. Innovation and design process
5 points
Total
69 points
RATING
POINTS
LEED-Certified
26-32
LEED-Silver
33-38
LEED-Gold
39-51
LEED-Platinum
52-69
Table 1.3 – LEED prerequisites and rating points.
1.7.2 TERI GRIHA The Energy and Resources Institute –Green Rating for Integrated Habitat Assessment
Internationally, voluntary building rating systems have been instrumental in raising awareness and popularizing green design. However, most of the internationally devised rating systems been tailored to suit the building industry of the country where they were developed. TERI, being deeply committed to every aspect of sustainable development, took upon itself the responsibility of acting as a driving force to popularize green building by developing a tool for measuring and rating buildings environmental performance in context of India‘s varied climate and building practices. This tool, by the quantitative and qualitative assessment criteria, would be able to ‗rate‘ a building on the degree of its greenness. The rating would be applied to new and existing building stock of varied functions-commercial, residential and institutional. 10
1.7.3 MINERGIE MINERGIE is a registered quality label for new and refurbished low-energy consumption buildings. This label is mutually supported by the Swiss Confederation, the Swiss Cantons and the Principality of Liechtenstein along with Trade and Industry. The label is registered in Switzerland and around the world and is thus protected against unlicensed use. The Minergie label may only be used for buildings, services and components that actually meet the Minergie standard. Building to Minergie standards means providing high-grade, air-tight building envelopes and the continuous renewal of air in the building using an energyefficient ventilation system. Specific energy consumption is used as the main indicator to quantify the required building quality. In this way, a reliable assessment can be assured. Only the final energy consumed is relevant. At present around 13% of new buildings and 2% of refurbishment projects are Minergie certified. These are mostly residential buildings. The goals of the Swiss national Swiss Energy Infrastructure and environment program call for 20% of new construction and 5-10% of refurbishment projects to be Minergie certified. The Minergie standard is somewhat comparable to German KfW40 (new buildings) and KfW60 (refurbishment) standards.
1.7.4 BREEAM BREEAM (Building Research Establishment‘s Environmental Assessment Method) is the world‘s leading and most widely used environmental assessment method for buildings, with over 115,000 buildings certified and nearly 700,000 registered. It sets the standard for best practice in sustainable design and has become the de facto measure used to describe a building‘s environmental performance. Credits are awarded in ten categories according to performance. These credits are then added together to produce a single overall score on a scale of Pass, Good, Very Good, Excellent and Outstanding. The operation of BREEAM is overseen by an independent Sustainability Board, representing a wide cross-section of construction industry stakeholders. 11
Objectives of BREEAM: · To provide market recognition to low environmental impact buildings · To ensure best environmental practice is incorporated in buildings · To set criteria and standards surpassing those required by regulations and challenge the market to provide innovative solutions that minimize the environmental impact of buildings · To raise the awareness of owners, occupants, designers and operators of the benefits of buildings with a reduced impact on the environment · To allow organizations to demonstrate progress towards corporate environmental objectives
Type of projects that can be assessed using BREEAM A BREEAM assessment can be carried out at the above stages for the following types of building project: · New Construction · Major refurbishment to existing buildings · New construction to an existing building i.e. an extension of existing building · A combination of new construction and major refurbishment to an existing building · New construction or major refurbishment, which forms part of a larger mixed use building · Existing building fit-out
ENERGY STAR Green Star is a voluntary environmental rating system for buildings in Australia. It was launched in 2003 by the Green Building Council of Australia. The system considers a broad range of practices for reducing the environmental impact of buildings and to showcase innovation in sustainable building practices, while also considering occupant health and productivity and cost savings. Nine categories are assessed with the Green Star tools:[1]
Management 12
Indoor environment quality
Energy
Transport
Water
Materials
Land Use & Ecology
Emissions
Innovation
1.8 TERI (THE ENERGY AND RESOURCES INSTITUTE)
1.8.1 Introducing TERI A dynamic and flexible organization with a global vision and a local focus, TERI (The Energy and Resources Institute ) was established in 1974. While in the initial period, the focus was mainly on documentation and information dissemination, research activities in the fields of energy, environment, and sustainable development was initiated towards the end of 1982. All these activities were rooted in TERI‘s firm conviction that efficient utilization of energy, sustainable use of natural resources, large - scale adoption of renewable energy technologies, and reduction of all forms of waste would move the process of development towards the goal of sustainability. A unique developing-country institution, TERI is deeply committed to every aspect of sustainable development. From providing environment-friendly solutions to rural energy problems to helping shape the development of the Indian oil and gas sector; from tackling global climate change issues across many continents working in partnership with local communities to help conserve forests ; from advancing solutions to the growing urban transport and air pollution problems to promoting energy efficiency in the Indian industry, the emphasis has always been on finding innovative solutions to make the world a better place to live in. Although TERI‘s vision is global, its roots are firmly entrenched in the Indian soil. All activities in 13
TERI move from formulating local- and national-level strategies shaping global solutions to critical energy and environment-related issues. To this end TERI has established regional centres in Bangalore, Goa, Guwahati, and Kolkata (recently Mumbai also), and has a presence in Japan and Malaysia. It has set up affiliate institutes: TERI–NA (Tata Energy and Resources Institute, North America) Washington, DC, USA, and TERI–Europe, London, UK. As an extension of its work on environment management, TERI has designed TERI– GRIHA (TERI-Green Rating for Integrated Habitat Assessment).
1.8.2 TERI green building rating system: TERI–GRIHA 1.8.2.1 The context Internationally, voluntary building rating systems have been instrumental in raising awareness and popularizing green design. However, most of the internationally devised rating systems have been tailored to suit the building industry of the country where they were developed. TERI, being deeply committed to every aspect of sustainable development, took upon itself the responsibility of acting as a driving force to popularize green building by developing a tool for measuring and rating a building's environmental performance in the context of India's varied climate and building practices. T his tool, by its qualitative and quantitative assessment criteria, would be able to ‗rate‘ a building on the degree of its ‗greenness‘. The rating would be applied to new and existing building stock of varied functions – commercial, institutional, and residential.
1.8.2.2 The challenges The Indian building industry is highly decentralized, involving diverse stakeholders engaged in design, construction, equipment provision, installation, and renovation of buildings. Each group may be organized to some extent, but there is limited interaction among the groups, thus disabling the integrated green design and application process. Hence, it is very important to define and quantify sustainable building practices and their benefits. It is also imperative to delineate the role of
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each actor in ensuring that the building consumes minimal resources in its entire life cycle and leaves behind minimal environmental footprint.
1.8.2.3 The benefits TERI's green building rating will evaluate the environmental performance of a building holistically over its entire life cycle, thereby providing a definitive standard for what constitutes a ‗green building‘. The rating system , based on accepted energy and environmental principles, will seek to strike a balance between the established practices and emerging concepts, both national and international. The guidelines/criteria appraisal may be revised every three years to take into account the latest scientific developments during this period. On a broader scale, this system, along with the activities and processes that lead up to it, will benefit the community at large with the improvement in the environment by reducing GHG (greenhouse gas) emissions, improving energy security, and reducing the stress on natural resources. Some of the benefits of a green design to a building owner, user, and the society as a whole are as follows : § Reduced energy consumption without sacrificing the comfort levels § Reduced destruction of natural areas, habitats, and biodiversity, and reduced soil loss from erosion, etc. § Reduced air and water pollution (with direct health benefits) § Reduced water consumption § Limited waste generation due to recycling and reuse § Reduced pollution loads § Increased user productivity § Enhanced image and marketability
1.8.3 EVALUATION CRITERION AND SCORING POINTS Criterion Description
Points
1
2
Design to include existing site features
15
2
Preserve and protect landscape during
5
construction 3
Soil conservation
4
4
Reduce hard paving on site
2
5
Enhance outdoor lighting system efficiency
4
6
Plan utilities efficiently and plan optimize
3
site circulation 7
Provide at least minimum level of sanitation 2 facilities for construction workers
8
Reduce air pollution during construction
2
9
Reduce landscape water requirement
3
10
Reduce building water use
2
11
Efficient water use during construction
1
12
Optimize building design to reduce
6
conventional energy demands 13
Optimize energy performance of building
12
within specified comfort 14
Utilization of fly ash in building structures
6
15
Reduce volume, weight and time of
4
construction by adopting efficient technology 16
Use low energy materials in interiors
4
17
Renewable energy utilization
3
18
Renewable energy based hot water system
2
19
Waste water treatment
2
20
Water recycle and reuse
5
21
Reduction in waste during construction
2
22
Efficient waste segregation
2
16
23
Storage and disposal of waste
2
24
Resource recovery from waste
2
25
Use of low VOC paints
4
26
Minimize ozone depletion substances
3
27
Ensure water quality
2
28
Acceptable outdoor and indoor noise levels
2
29
Tobacco and smoke control
1
30
Energy audit and validation
Mandatory
31
Operation and maintenance protocol for
2
electrical and mechanical equipments 32
Bonus
4
Total
100 Table 1.4 – Evaluation criterion of TERI-GRIHA
1.8.4 RATING
RATING
POINTS
1 STAR
51-60
2 STAR
61-70
3 STAR
71-80
4 STAR
81-90
5 STAR
91-100 Table 1.5 – Rating points of TERI-GRIHA
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CHAPTER 2 METHODOLOGY
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2.1 AIM OF THE PROJECT The aim of this design thesis is to study the green concepts, understanding their viability and using them to design an administrative block, which will prove to be an iconic building, a standing example of a green building which would be healthy for the people inside as well as outside. Such design can be termed as a ―sustainable design‖ At the same time, the idea of taking an institutional administrative building as a typology is to prove that the focus is not just environment but also spreading the green concept. The design aims at providing an eco-friendly place, which is not only healthy for its occupants and environment but also increasing the awareness.
2.2 SCOPE & LIMITATIONS
The concept of green buildings though popular among professional has yet not reached the common man properly. The main idea behind the project is to make the green concept assessable to the common man so that they can appreciate its importance. There are various misconceptions regarding the cost and economic viability of green buildings which needs to be clarified. The main challenge of this design problem will be inter-linking the various functions performed by the building and at the same time not compromising with the energy efficient aspect of the structure.
2.3 RESEARCH AND PRE- DESIGN STUDY The entire thesis revolves round the idea behind the topic which was to find out the relevance of green architecture and study the parameters and requirements of a
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green building. The idea is also to apply these concepts in the design solution and get a first hand experience in designing a green building and face the challenge. CHAPTER 1 – INTRODUCTION
This chapter explains the meaning of a green building. It tells about the importance of green building in today‘s scenario and proves its economical viability. It further explains the concept of an administrative building in an educational institution and also the need of such a project. It also talks about the various rating systems and points given to rate a building green CHAPTER 2 – METHODOLOGY
This chapter goes on explaining the exact method by which the thesis is going to be carried out including a chapter to chapter description of the design thesis, including the main aims and objectives of the thesis , with the scope and limitations of the topic including the main areas that will be concentrated during the thesis CHAPTER 3 – DATA COLLECTION
The data collection would include all relevant data required in designing a Green administrative building.
The data to be collected would be decided from the program requirements and the inferences from case studies. This data would further be used as references during the design process.
The data collected is Various green measures and their applications according to TERI-GRIHA. Hierarchy of administrative staff of N.I.T. Office spaces and other space requirements. Apart from this data collection analysis will be done on 20
Efficient landscaping Glass in green architecture Utilization of fly ash in building structures Rain water harvesting Waste water management The data collection will also include guidelines given by TERI for designing a building with green features in sync. CHAPTER 4 – CASE STUDY
The main aim of this chapter would be to put forward the kind of functions present in parallel case studies of green buildings, realizing their positive and negative points.
The chapter will end in an analysis and conclusion which will finally help in the program requirements, site selection and limits of the site.
The case studies selected are 1. CESE BUILDING, IIT KANPUR. 2. MNNIT ALLAHABAD.
CHAPTER 5- SITE SELECTION AND ANALYSIS
The chapter would include the reason for selecting the site and the site details.
CHAPTER 6- DESIGN APPROACH
The chapter will explain the initial design concept for development of building form.
CHAPTER 7- FINAL PROPOSAL
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CHAPTER 3 GREEN DESIGN CONCEPTS
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3.1 Design to include existing site features 3.1.1 Objective The natural functions of a plot of land (hydrologic, geologic, and microclimatic) can be seriously disrupted by the placement of a building on it. The design of a green building will factor in the ways in which the natural site features can be protected or even restored. Layout the site activities and building requirements after carrying out detailed site analysis so as to ensure sustainable site development in tune with its topographical, climatic, and ecological character.
3.1.2 Site inventory and design impacts
Table 3.1 – Site inventory and design impacts
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3.2 Reduce hard paving on site/and or provide shaded hard paved surfaces 3.2.1Objective To reduce hard paving on - site (open area surrounding building premises) and/or provide shade on hard paved surfaces to minimize the heat island effect and imperviousness of the site.
3.2.2 Heat island effect Dark coloured and constructed surfaces are prone to absorption and retention of solar energy. The retained solar energy also gets re-radiated to atmosphere during times when ambient temperature gets cooler. This gives rise to warmer temperatures in urban landscapes, which have large areas of constrained surfaces low on reflectance. This phenomenon of increased temperature in urban landscape is called heat island. Principle surfaces that contribute to the heat island effect include streets, sidewalks, parking lots, and buildings. Heat island effect can be minimized by use of shading or reflective surfaces. As mentioned, hard paved surfaces are one of the major constraints of heat in land effect.
In addition to causing heat island effect, hard pavements also reduce perviousness of site. Enhanced perviousness of site minimizes storm water runoff and is beneficial for localized aquifer recharge. This method aims to encourage design measures to minimize negative impacts of the paved areas.
3.2.3 Best practices Planting trees, bushes, or a properly planned landscaping can help reduce the heat island effect by reducing ambient temperatures through evapotranspiration. Plant vegetation around the building to intercept solar radiation and to shade the walls and windows of buildings (with S, SW or SE exposure) to prevent heat gain. This would also help in reducing air-conditioning load/use. 24
Use light coloured, reflective roofs having an SRI (solar reflectance index) of 50% or more. The dark colored, traditional roofing finishes have SRI varying from 5% to 20%. The fine example of higher SRI is the use of broken china mosaic, light coloured tiles as roof finish, which reflects the heat off the surface because of high solar reflectivity, and infrared emittance which prevents heat gain. Use commercially available, high solar reflective (albedo) roof coatings or heat reflective paints on roofs used to shade paved areas. Don't use stone mulches such as fine gravel, crushed granite or pebbles in unplanted areas immediately adjacent to buildings, as they can heat up, reflect solar radiation inside, and also cause glare. Use high albedo or reflective pavements to keep parking lots, pavements and inside roads cool because the increase in albedo decreases the pavement temperature approximately by 8°F for a change in albedo of 0.1. Use light coloured aggregates or ‗whitetop‘ the pavements with 50 mm thick layer of cement concrete. Stabilize the pavements with porous or permeable materials such as sand, crushed bricks, broken mosaic tiles or stones where the soil is stable or the traffic load is quite low. Recycled materials such as demolished concrete (rubble), broken china and mosaic tiles could also be used.
3.2.4 Commitments Total paved area of the site under parking, roads, paths, or any other use not to exceed 25% of the site area or net imperviousness of the site not to exceed the imperviousness factor as prescribed by the National Building Code of India, Bureau of Indian Standards,2005; Part 9 (Plumbing services) Section 5.5.11.2.1, whichever is more stringent. Total surface parking not to exceed the area as permissible under the local bylaw and
pavement/grass pavers, or
vegetated roof/pergola with planters, or 25
50% of the paved area (including parking) to be topped with finish having solar reflectance of 0.5 or higher.
3.3 Enhance outdoor lighting system efficiency
3.3.1 Objective Enhance energy efficiency of outdoor lighting and promote usage of renewable forms of energy to reduce the use of conventional/fossil fuel based energy resources. Luminous efficacy of external light sources used for outdoor lighting shall equal or exceed as specified.
3.3.2 Minimum allowable values of luminous efficacy of lamps for outdoor lighting Light source
Minimum allowable luminous efficacy
(lm/W) CFL (Compact fluorescent lamps)
50
FL (Fluorescent lamps)
75
MH (Metal Halide)
75
HPSV (High pressure sodium vapour lamp)
90
All outdoor lightings to be fitted with an automatic on/off switch. A minimum 25% of the total number of outdoor lighting fixtures to be powered by solar energy. Outdoor lighting system includes (i) Security lighting, (ii) Street lighting, (iii) Landscape lighting, (iv) Façade lighting, and (v) Parking lighting
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3.4 Reduce landscape water requirement
3.4.1 Objective To reduce the landscape water requirement for so as to minimize the load on the municipal water supply and depletion of groundwater resources.
3.4.2 Best practices to reduce water usage for landscaping Xeriscaping Xeriscape means the conservation of water and energy through creative landscaping. This word is derived from the Greek word Xeros meaning dry and these plants can live, once established, with little or no supplemental watering. Some are drought tolerant. It is recommended that: §The landscape should be a mix of native shrubs and xeriscape plants. Reduce the lawn area, and plant more of trees that require no water after establishment. Plant palm trees which are xerophytic such as Phoenix dactylifera, Yucca starlite. Use ground covers such as Asparagus sprengeri, which is succulent, Pandanus dwarf which is xerophytic, and Bougainvillea which is a climber.
Drip irrigation Drip irrigation system or sub-surface drip irrigation system results in saving of water as it avoids loss of water due to run-off, deep percolation, or evaporation. Sprinkler irrigation Sprinkler irrigation is a method similar to natural rainfall in which water is distributed through a system of pipes. For maintaining uniform distribution of water, the pump supply system, sprinklers and operating conditions must be designed appropriately. Sprinklers are most suited to sandy soils with high infiltration rates. The average application rate should be less than the basic infiltration rate of the soil so as to avoid surface ponding and run-off. It is better
27
to use sprinklers that produce fine sprays and not those that produce larger water droplets. Native vegetation Native vegetation is original to a particular place, including trees, shrubs, and other plants Evapo-transpiration rate The potential evapo-transpiration rate (PET) is the climate factor, refers to the amount of water required by the plant for healthy growth (depending on the climate). Evapo-transpiration rate determines the rate at which plants lose water through evaporation. It is affected by humidity and temperature at a given time. These rates vary with the season and are different for different months. The data is available with the Indian Meteorological Department for each city.
3.4.3 Efficiencies of irrigation systems Irrigation efficiency refers to the ability of an irrigation system to deliver water to plants without evaporation or other means of water loss. Irrigation system Efficiency Micro, drip
85%
Micro, spray
80%
Multiple sprinkler
75%
Sprinkler, large guns
70%
Seepage
50%
Crown flood
50%
Flood
50%
3.4.4 Commitment Design the landscape so as to reduce water consumption by minimum 30%.
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3.5 Reduce the water use by the building
3.5.1 Objective To reduce the water consumption in the building by using efficient fixtures.
3.5.2 Best practices 1) Use of efficient plumbing fixtures, sensors, auto valves, pressure reducing device wherever possible can result in significant reduction in water consumption 2) Water efficient fixtures § Conventional toilets use 13.5 litres of water per flush. Low flush toilets are available with flow rate of 6.0 litres and 3.0 litres of water per flush. § Dual flush adapters can be used for standard flushing for solid waste and a modified smaller flush for liquid waste. § Flush valves with 20–25 mm inlets can be used for restricting the water flow § Composting toilets § Water-efficient urinals The conventional urinals use water at a rate of 7.5–11 litres per flush. Use of electronic flushing system or magic eye sensor can further reduce the flow of water to 0.4 litres per flush. Waterless urinals use no water. 3) Auto control valves Installation of magic eye solenoid valve (self-operating valves) can result in water savings. The sensor taps has automatic on and off flow control. It is not only convenient and hygienic but also an excellent water saving device that can work under normal water pressure. It functions with parameters such as distance and timing. 4) Pressure reducing device Aerators and pressure inhibitors for constant flow. Use of aerators can result in flow rates as low as 2 litres per minute, which is adequate
3.5.3 Commitment Reduce the total water consumption in the building by a minimum of 25%
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3.6 Optimise building design to reduce conventional energy demand
3.6.1 Objective To apply solar passive measures including day lighting to reduce the demand on conventional energy for space conditioning and lighting systems in buildings. 3.6.2 Passive solar concept Buildings should minimize their dependence on conventional systems of heating, cooling, ventilation and lighting which consume electricity produced from non renewable sources of energy. Solar passive buildings are designed to achieve thermal and visual comfort by using natural energy sources and sinks eg, solar radiation, outside air, wet surfaces, vegetation etc. The solar passive design strategy should vary from one climate to another. For example in Hyderabad which falls in Hot & dry climate zone, evaporative cooling could be very effective, however, in warm & humid climate zone water has to be removed from air to provide comfort.
3.7
Optimize energy performance of building within specified comfort limits
3.7.1 Objective To optimize energy use in energy systems in buildings that maintains a specified indoor climate conducive to the functional requirements of the building
3.7.2 Commitments
Follow mandatory compliance measures (for all applicable buildings) as
recommended in the Draft energy conservation building code of the Bureau of Energy Efficiency, Government of India.
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Show that energy consumption in energy systems in a building under a
specified category is less than the benchmarked energy consumption figure. The energy systems include air conditioning, indoor lighting system, water heating, air heating and air circulation devices within the building.
The annual energy consumption of energy systems in a fully air
conditioned building for day use in a composite climate should not exceed 140 kWh/m2 (kilowatt hour per square metre) (benchmarked energy consumption figure).
The annual energy consumption of energy systems in a fully non-air
conditioned building for day use should not exceed 26 kWh/m2 (benchmarked energy consumption figure).
In a building that includes air– conditioned and non-air conditioned
areas, the annual energy consumption of energy systems in totally air conditioned areas for day use should not exceed 140 kWh/m2 and the annual energy consumption of energy systems in totally non-air conditioned areas for daytime operation should not exceed 26 kWh/m2.
Quantify energy usage for all electrical, mechanical, and thermal
systems for which either electrical or thermal energy is being used and which are being used to provide lighting, air conditioning, ventilation, heating (water and air), and air circulation.To convert thermal energy to electrical energy following table can be used. Energy conversion factors
Energy unit Conversion factor for kWh
Litres of LDO (light diesel oil)
8.3
Litres of HSD (high speed diesel)
8.5
kg of LPG (Liquefied petroleum gas)
13.9
SCM (Standard cubic metres) of PNG (Pipe natural gas)
7.0
31
3.8 Utilization of flyash in building structure
3.8.1 Objective To use low embodied energy industrial waste fly ash as the construction material. Fly ash, an industrial waste having the properties of cement and very low embodied energy is used in combination with cements that are high in embodied energy.
3.8.2 Best practices for flyash
Use ready mix concrete or high-volume fly ash concrete for construction
(commercially available from L&T, ACC etc.) or use PPC concrete for construction (commercially available by ACC suraksha, Lafarge cement, L&T cement, Jaypee Buniyad, Pn'sm Champion etc, PPC must meet the requirements of IS 1489:1991}.
Portland pozzolona cement
This cement is equivalent to OPC (Ordinary portland cement) in mechanical strength, setting, and hardening and is an alternative to OPC, with an additional advantage of having mild sulphate resistance. Pozzolana cement or PPC (Portland Pozzolana Cement) is a mixture of ordinary Portland cement (65%-85%) and a pozzolana (15%-35%). Sometimes, PPC concrete develops strength at a slower rate than OPC concrete. Calcined clay and fly ash are the most common pozzolana for PPC, Addition of fly ash significantly improves the quality and durability characteristics of resulting concrete.
High volume fly ash concrete High volume fly ash concrete develops
sufficient early strength and workability, in addition to low temperature rise and high ultimate strength. This is possible due to high dosage of plasticizer and low W/C ratio to the extent of 0.30-0.35, ratio of cement, fly ash, fine and coarse aggregates-1:1.75:3.5 with compressive strength reaching 40-45Mpa on the 90th day.
3.8.3 Fly ash based innovative and commonly produced building products in India
Cellular light weight concrete blocks 32
CLC (Cellular light weight concrete) blocks are substitute to bricks and conventional concrete blocks in building with density varying from 800 kg/m3 to 1800 kg/m3, The normal constituents of this are foaming agent based technology cement, fly ash (to the extent 1/4"1 to 1/3r" of total materials constituent), sand, water and foam (generated from biodegradable foaming agent). Using CLC walling and roofing panels can also be produced.
Advantages of CLC
Better strength to weight ratio
Reduction of dead load resulting in saving of steel and cement and
reduction in foundation size
Better acoustics and thermal insulation (air conditioning requirement is
considerably reduced)
Saving in consumption of mortar and higher fire rating
Development of fly ash based polymer composites as wood substitute
Fly ash based composites have been developed using fly ash as filler and
jute cloth as reinforcement. After treatment, the jute cloth is passed into the matrix for lamination. The laminates are cured at specific temperature and pressure,
Numbers of laminates are used for required thickness. The technology on
fly ash polymer composite using jute cloth as reinforcement for wood substitute material can be applied in many applications like door shutters, partition panels, flooring tiles, wall paneling, ceiling, etc.
With regard to wood substitute products, it may be noted that the developed
components/materials are stronger, more durable, resistant to corrosion and above all cost-effective as compared to the conventional material i.e. wood.
Ready mixed fly ash concrete Though ready mix concrete is quite popular in developed countries but in India it consumes less than five per cent of total cement consumption. Only recently its application has started growing at a faster rate. On an average, 20% fly ash (of cement material) in the country is being used which can easily go very high. In 33
ready mix concrete, various ingredients and quality parameters are strictly maintained/controlled which is not possible in the concrete produced at site and hence it can accommodate still higher quantity of fly ash.
Fly-ash-sand-lime-gypsum (cement) bricks/blocks
Fly ash can be used in the range of 40-70%. The other ingredients are lime,
gypsum (cement), sand, stone dust/chips etc. Minimum compressive strength (28 days) of 70 kg/cm2 can easily be achieved and this can go upto 250 kg/cm2 (in autoclaved type).
Advantage of these bricks over burnt clay bricks
Lower requirement of mortar in construction
Plastering over brick can be avoided
Controlled dimensions, edges, smooth and fine finish and can be in
different colors (using pigments)
Cost-effective, energy-efficient and environment friendly (as avoids the use
of fertile clay)
Clay-fly ash bricks, Fly ash content can be 20%-60% depending on the
quality of clay. Process of manufacturing is same as for the burnt clay bricks.
Fuel requirement is considerably reduced as fly ash contains some
percentage of unburnt carbon
Better thermal insulation
Cost effective and environment friendly
3.8.4 Application of fly ash
Reinforced concrete (RC) (including ready mix concrete) to make use of fly
ash by using PPC containing fly ash. (Minimum 15% replacement of cement with fly ash in PPC (Portland Pozzolona Cement) by weight of the cement used in the overall RC for meeting the equivalent strength requirements).
Use fly-ash in building blocks for the wall. Use of fly ash- based
bricks/blocks (for e.g., Fal-G stabilized, fly ash-sand lime bricks, load bearing and non-load bearing fly ash- based concrete blocks, fly ash- based light weight aerated concrete walling blocks etc.) in case of both load- bearing and non-load
34
bearing wall systems, which utilize a minimum 40% of fly ash by weight of cement for 100% load bearing and non-load bearing walls.
Use fly ash in Plaster/masonry mortar by employing PPC. Use plaster
and/or masonry mortar, which utilizes a minimum 30% of fly ash in PPC, in 100% wall/ceiling finishes and wall construction, meeting the required structural properties.
3.9 Use low energy material in interiors 3.9.1 Objective To use low-energy/recycled materials/finishes/products in the interiors, which minimize the use of wood as a natural resource, and use low-energy materials and products, such as composite wood products/rapidly renewable materials/ reused wood/low embodied energy products/products which utilize industrial waste/ recycled products. The various interior finishes used in the sub-system of the building or the interior, which serve the aim of the credit, have been divided into the following three major categories. -assembly/internal partitions/Interior wood finishes/paneling/false ceiling/In-built furniture/cabinetry Flooring Doors/windows, frames
3.10 Renewable energy utilization 3.10.1 Objective To use of renewable energy sources in buildings to reduce the use of conventional /fossil fuel- based energy resources
3.10.2 Use of renewable energy sources
35
Renewable sources of energy (such as solar, wind, biomass, geothermal, etc.) can provide the energy required for meeting the building energy demand. These sources are environmentally clean and non-exhaustible. Natural sources of energy such as solar, wind, hydro power, tidal energy, ocean thermal and hydrogen are all renewable energy sources. Projected availability of fossil fuels in future and environmental degradation (including global warming) associated with usage of these fuels are the driving forces for increasing use of renewable energy sources.
3.10.3 Various renewable energy technologies
Power Generation Technologies Wind Power Small Hydro Power Biomass Energy and Cogeneration
Biomass power
Biomass Cogeneration
Bagasse Cogeneration
Biomass gasification
Energy from Waste
Solar Energy Technologies Solar Thermal
Solar water heating
Solar air drying
Solar cooker
Solar Photovoltaic
Solar home lighting
Solar Photo Voltaic water pumping
Solar lantern
Rural Energy Technologies Biogas Improved Chulhas
New Technologies Fuel Cells Hydrogen Energy 36
Geothermal Ocean Energy Tidal Energy Ethanol Biodiesel
3.10.4 Commitment Energy requirement for a minimum 10% of internal lighting load (for general lighting) or its equivalent is met from renewable energy sources (solar, wind, biomass, fuel cells, etc.).
3.11 Renewable energy based hot water system 3.11.1 Objective To use renewable energy sources to meet the hot -water need.
3.11.2 Guidelines for installation and use of solar systems
Solar collectors should face south for maximum solar radiation collection.
Solar collector tilt should be equal to the latitude of the place for maximum
annual energy collection.
Solar collector tilt equal to latitude + 150 gives maximum energy collection
in winter.
Solar collector tilt equal to latitude -150 gives maximum energy collection
in summer.
Always check load carrying capacity of the roof before placing the solar
system. Typically, each solar collector of 2 m2 area weighs 50 kg. The solar tank when filled with water weighs 1.2–1.4 kg per litre capacity of tank. (For example, 100 litre capacity tank weighs 120 kg)
Ensure proper anchoring of the system duly considering wind conditions.
Solar collectors and tank must be easily accessible for cleaning and
maintenance. 37
Typically solar system needs 1.3–1.5 times the collector area for
installation. For example, a single collector system of 100 litre capacity having 2 m2 area needs 3 m2 of floor area for installation.
3.11.3 Guidelines for solar system selection and use
Check hardness of water to be used in solar system. Solar collectors have
small diameter pipes, which get chocked due to deposition of salt from hard water. In case of hard water, either water softener or heat exchanger type solar water heater can be used.
It is a good practice to consider solar system location and optimize the
associated hot/cold water piping layout during the building design stage to reduce the cost and heat losses due to longer piping.
Always use good quality pipes and insulation for long life and trouble-free
working.
It‘s important to check operating pressure of supply of cold water line,
especially when pressurized water is circulated. Most solar systems available in India are not designed for pressurized water supply. Ensure continuous supply of water to the solar system for efficient and trouble-free operations.
During long periods of no use (for example, while on vacation) always
cover the solar collectors with nontransparent covers (e.g. old bed sheet or jute cloth)/to avoid overheating of solar system).
It is a good practice to use the entire hot water at a time.
Avoid using back up heater. Do not keep back-up heater switched on.
Set the thermostat of back-up heater at 55–600C.
Use proper vent or vacuum release valve and pressure relief valve for safe
operation of solar system.
Human body can tolerate temperature up to 450 C. Human skin burns at
water temperature above 550C. Storage water heater temperature can be set at 55+50C.
3.11.4 Guidelines for system sizing
Typically solar hot water system is sized to meet one day‘s requirement of
hot water during winter. Typical hot water consumptions for various activities are 38
given below. These can be used as guidelines for calculating total hot water requirement. (The consumption figures may vary depending on life style, age, habits, and weather conditions.)
For bathing using bucket water = 15 litre per person per day (one bucket).
For shower bath = 25 litre per person per day.
For bath tub = 35–50 litre per person per day.
For cooking = 5 litre per person per day.
For washing clothes = 10 litre per person per day.
For washing utensils etc. = 5 litre per person per meal.
For making tea/coffee = 150 ml per person per cup
3.11.5 Commitment Ensure that a minimum 50% of the annual energy requirement for heating water (for application such as hot water for all needs except for space heating, e.g. for canteen, washing, bath rooms/toilets) is supplied from renewable energy sources.
3.12 Water recycle and reuse (including rainwater) 3.12.1 Objective To utilize the treated waste water and rainwater for various applications (including groundwater recharge) where potable municipal water is normally used to reduce the load on both the municipal supplies as well as the sewerage system and to improve the groundwater level
3.12.2 The basic concept of storage and recharging The recharging or storing of water depends on the rainfall of a particular region, and the sub-surface geology. In regions where the rainy season lasts for three to four months, groundwater recharge is beneficial rather than storage, as the storage cistern would remain empty during other parts of the year. In places where the surface is impermeable and groundwater is saline or not of potable quality, it is not advisable to go for groundwater recharging. Recharging can be done through dugwells, borewells, recharge trenches, and recharge pits. Filter material at the 39
entry point is essential to maintain the quality of water. Settlement tank acts as a buffer to hold the surplus water during the course of excess rainfall.
3.12.3 RAINWATER HARVESTING "An Innovative Approach to Solve Water Crisis" "Water is a strange natural resource. It can unite a community as easily as it can divide it." 'Rainwater Harvesting' implies nothing but conservation of rainwater. Rainwater Harvesting (RWH) is a tradition-renewed scientific technology applied to augment the groundwater both quantitatively and qualitatively. Rain Water Harvesting is a simple, economical but effective way to save rainwater for consumption and artificial recharge to solve the water problem naturally. India is one of the water rich countries of the World. The average annual precipitation in India, 1150 mm, is higher than that of every other continent in the world except South America (1596 mm) and twice that of the average annual precipitation of the continent of Asia. 100 hours, in a year, when it falls on in those few hours, when the rivers and streams swell up, then there is little water to capture to meet human needs. Every time it rains, only about 5-20% of the total rain is recharged into the ground depending upon
the
terrain,
top
soil
condition,
subsurface
formation,
rainfall pattern, etc. The topsoil can hold only a fraction of water that falls on it and the rest gradually percolates down, depending on the type of the soil and joins the aquifers.
India is a water rich country India is one of the nine countries which hold 90% of fresh water of the world 1. Brazil 2. The russian federation 3. Canada 4. Indonesia 5. China mainland 6. Columbia 7. Usa 40
8. Peru
9. India
Artificial recharge Artificial recharge may be defined as the practice of increasing by artificial means, the amount of water that enters the ground water reservoir. This is accomplished by unique systems and techniques, depending on the site specifications.
How does a rainwater-harvesting system work? A rainwater harvesting system runs on the principle of seepage of water into the ground. Owing to various soil features, water from rainfall is often obstructed from reaching an aquifer that is several metres underground. In the case of rainwater harvesting, water infiltrates into an aquifer through an artificial recharge structure and recharges the aquifer accordingly. Thus, rainwater falling on the surface has a smooth passage to the aquifer, where it is stored; from there it can be retrieved for future use. Certain places do not have natural aquifers. In such cases, it is possible to construct artificial aquifers. These man-made aquifers are as effective as natural ones for the purpose of storage and retrieval of water.
3.12.4 Commitment
Provide necessary treatment of waste water for achieving the desired
composition for various applications
Implement rainwater harvesting and storage systems depending on the
site-specific conditions.
Reuse the treated waste water and rainwater for meeting the building
water and irrigation demand.
Recharge the surplus water (after reuse) into the aquifer.
3.13 Use low -VOC paints/ adhesives/ sealants
41
3.13.1 Objective Paints can have a major impact on the overall aesthetics of a space; sometimes more than even flooring and furnishings because of the enormous square footage coverage. Paints may also have a major negative impact on the indoor air quality of a building, because they may contain chemicals called Volatile organic compounds (VOCs) and other toxic components that evaporate into the air and are harmful to the health of the occupants. VOCs are a primary contributors to smog generation.
3.13.2 Environmental effects of paints Paints have three major components: a pigment for color. A binder that holds the pigment to the surface and a carrier or solvent (mineral spirits or water) to dissolve and maintain the pigment. Latex, water based paints have significantly lower environmental impacts than oil or solvent-based paints since they don‘t use petroleum carriers or have nearly as many smog forming emissions. According to the US Environment Protection Agency (USEPA), 9% of the airborne pollutants creating ground level ozone come from the VOCs in paint. Low and zero VOC paints have little or no smog-forming emissions.
3.13.3 Potential Health Effects of Paints Paints is applied wet and must undergo a drying process, and sometimes a chemical reaction, in order to form a solid paint film on the wall or other surfaces. It is during this drying or chemical process that VOCs and other paint component are released. Many paints contain a high percentage of VOCs so that they will dry faster. Paints also continue to offgas somewhat for many days, weeks, and months after application and especially each time the temperature and humidity in the room rises VOC refers to the class of chemicals which evaporate readily at room temperature. They are in all oil-based paints as solvents. Many latex paints (which use water as the ―solvent‖ or carrier) also contain VOCs as a part of their paint chemistry. When these VOCs off gas, they may cause a variety of
42
health problems like nausea, dizziness, irritation of the eyes and respiratory tract and more serious illness like heart, lung or kidney damage and cancer.
On air quality, they are excellent for use in buildings where it is desirable to have very low levels of toxicity, such as hospitals, schools or the homes and workspaces. Once airborne, many VOCs have the ability to combine with each other, or with other molecules in the air, to create new chemical compounds. Air quality testing shows that indoor VOC levels are considerably ten times higher than outdoor levels, and can be as much as one thousand times higher after a new coat of paint.
3.13.4 Benefits of Low VOC Paints
Environmental
VOCs react with sunlight and nitrogen oxide in the atmosphere to form ground level ozone, a chemical that has a detrimental effect on human health, agricultural crops, forests and ecosystems. These problems can be eliminated using low VOC paints
Economic
Healthy occupants are more productive and have less illness related absenteeism. Use of high VOC content material can cause illness and may decrease occupant productivity. These problems result in increased expenses and liability for building owners, operators and insurance companies.
Indoor Environment
Selecting materials that are low in VOC helps reduce sources of pollutants during the construction process and in the finished building. Also low Voc paints have little odour.
3.13.5 Making Good Choices
Sometimes simply washing walls and/or using a little touch-up paint can
make them appear new. When it is necessary to paint, use least toxic and low or
43
non VOC products, and water based paints. This will also eliminate the need for toxic solvents for clean up.
Remember that a more durable paint is less expensive in the long run. A
10 year paint may cost a little more than a 5 year, but there is only a one time labor cost, which is the most expensive part of most paint jobs.
Proper preparation is also critical for a durable paint application. All
surface must be clean and dust free, with any visible cracking, peeling, or blistering removed.
If there is existing paint, determine what it is and appropriately prepare
for the next coat. Be sure to choose primers and top coats that are compatible.
3.14 Minimize ozone depleting substances
3.14.1 Objective Eliminate or control the release of ozone- depleting substances into the atmosphere. The ozone depleting materials commonly used in buildings are CFCs (chlorofluorocarbons) or HCFCs (hydro chlorofluorocarbons) in refrigeration and air- conditioning systems, insulation, and halons in fire suppression systems and extinguishers.
Substances containing Chlorine (or Bromine) contribute to the breakdown of the ozone layer in the stratosphere, resulting in harmful ultra violet radiation reaching earth's surface, and thus global climate change. Such substances are mainly used in refrigerating and air-conditioning equipment, fire suppression systems and extinguishers, and in insulation, and this has been a growing cause for concern. Therefore, continued efforts are being made globally (in the form of International agreements) to minimize the use of ozone depleting substances, and gradually to replace them with environmentally friendly substances. Trichlorofluoromethane (R11) is used as reference for measuring the Ozone
44
Depleting Potential (ODP) of a substance. ODP of R11 is 1. Some of the commonly used substances in refrigerating and air-conditioning equipment are listed in the table below.
3.14.2 Commitment Use insulation with zero -ODP (ozone depletion potential) such as HCFCfree rigid foam insulation, mineral fibre cellulose insulation, glass fibre, wood fibre board, cork wool, expanded (bead) polystyrene, recycled newspaper and jute, cotton etc. Avoid materials that do not inherently have a zero -ODP such as polyurethane foams, polyisocyanurates , etc. Install CFC-free equipment used for refrigeration and air conditioning. Install halon -free fire suppression systems and fire extinguishers in the building.
45
CHAPTER 4 CASE STUDY
46
4.1 CASE STUDY – 1
Centre for Environmental Science and Engineering, IIT Kanpur. 5-star GRIHA rated Green Building at IIT Kanpur.
47
Green Features
Existing landscape and vegetation is largely protected.
The first floor of the building has been pushed inside to protect a tree outside.
Water body is integrated with design for optimal microclimate.
An internal courtyard shaded by louvers is provided, so that to allow free air movement.
48
Natural light and ventilation through skylights & ventilators in common spaces.
Roof shaded by bamboo trellis with green cover to cut direct heat gain.
49
Large openings to maximize natural daylight into interiors.
Efficient glazing for openings which minimize solar gains in summer, heat loss in winter.
•
HVAC system Use of geothermal energy for cooling Efficient chillers
Lighting system Lamps with luminous efficacy – 75lm/w Average LPD < 1 W/ft2
50
Magic eye solenoid valves are installed in taps.
Aerators are used which reduces the flow rate to 2ltrs/min.
Magic eye sensors reduces water flow to 0.4 ltrs/flush.
Rain water from the building and surrounding area collected and routed through a sedimentation tank to water body for AC cooling.
Overflow is led to a groundwater recharge pit.
51
100% of outdoor lighting demand met by solar energy.
30% of internal lighting demand met from photovoltaic panels.
Solar water heater panels.
100% of hot water building requirement is met by solar system.
52
4.2 CASE STUDY – 2
ADMINISTRATIVE BUILDING, MOTILAL NEHRU NIT, ALLAHABAD
53
Salient features •
G+3 storey
•
2 entrances
•
Pathways – PCC Paving, Tiled paving
•
Parking – Paved, unshaded
•
Solar powered outdoor lights.
•
In corridors, artificial lighting is required during daytime.
•
Vertical movement – 2 stairs & 2 lifts.
•
Toilets – 2 male ( 3urinals, 2wc, 2wb) 2 female (2wc, 2wb) on each floor.
Administrative staff at MNNIT Allahabad. Administrative officers Deans
Officers in charge
Director
Chief warden.
Planning and development
Registrar
Academics
Training and placement
Dy. Registrar ( accounts)
Accounts
Purchase
Dy. Registrar ( academics)
Students affairs
Student welfare centre.
Public Information
Research and
Civil (M) academic
Officer
consultancy
campus.
Chief Vigilance Officer. Faculty welfare.
Civil (M) road maintenance
Medical officer
Civil (M) officers colony
A.E. ( mechanical)
Civil (M) hostel
A.E. (electrical)
Time table
Executive officer (
Chairperson – ICCM
director) Programmer
Chairperson – BOG
Foreman
Co-ordinator – design centre.
54
Floor-wise distribution of areas of administrative block, MNNIT Allahabad.
Ground floor •
Accounts office (105m²)
•
Public information centre (20m²)
•
Civil maintenance (58.5m²)
•
Chief proctor (33m²)
•
Accounts officer (21m²)
•
Main office (105m²)
•
Chief warden (22m²)
•
Dean (R & C)-22m²
•
Dean (P & D) – 22m²
•
Staff rooms – 2
•
Staff office – 3 (52.5m²)
•
Trophy room (30m²)
•
Male toilets – 2 (2wc, 2wb, 3Urinals)
•
Female toilets – 2 ( 2wc, 2wb)Toilet area – 60m²
•
Storage space (45m²)
•
Electric room (16m²)
•
Services (16m²)
•
Lifts - 2 (13.5m²)
First floor •
Board room (104.5m²)
•
Director‘s office (54m²) with attached •
Sitting room (20m²)
•
Toilet (5.4m²)
•
Store (15m²)
•
PA room (37.5m²)
•
PA staff (16m²)
•
Pantry (9.6m²)
•
Registrar with PA (50m²) 55
•
Deputy registrar (20m²)
•
Chairman‘s office with attached (37.35m²) •
Sitting (12.9m²)
•
Toilet (3.75m²)
•
Staff room (30m²)
•
Office (17.3m²)
•
Senate room (200.23m²)
•
Male toilet – 2 (2wc,2wb,3Urinals)
•
Female toilets – 2 (2wc, 2wb) Toilet area – 60m²
•
Store room (9.6m²)
•
Electric room (16m²)
•
Services (16m²)
•
Stairs – 2 (30m²)
• Lifts - 2 (13.5m²)
Second floor • Talk show and media room (104.5m²) • Equipment room (43.61m²) • Lab (31.7m²) • Placement cell (93m²) • Industry interaction (104.5m²) • Office of placement in charge (18m²) • Toilet (3.75m²) • Staff room (16.7m²) • Alumni association (30m²) • Offices – 5 (104.6m²) • Meeting room (23m²) • Change room – 2 (19m²) • Male toilet – 2 (2wc,2wb,3Urinals) • Female toilets – 2 (2wc, 2wb) Toilet area – 60m² • Store room – 2 (19.2m²) 56
• Electric room (16m²) • Services (16m²) • Stairs – 2 (30m²) • Lifts - 2 (13.5m²)
Third floor • Conference room – 2 (197.7m²) • Auditorium – 200 persons (200.23m²) • Offices – 6 (136m²) • Meeting rooms – 2 (50.9m²) • Store room – 4 (45.6m²) • Staff room (21m²) • Male toilets – 2 (2wc, 2wb, 3urinals) • Female toilets – 2 (2wc, 2wb) Toilet area – 60m² • Electric room (16m²) • AHU (38m²) • Stairs – 2 (30m²) • Lifts - 2 (13.5m²)
57
CHAPTER 5 SITE ANALYSES
58
ANALYSES.
Site and area statements. Location of the site:
Figure 5.1 – Site location
The proposed site is on national highway 200, 22 km from the Raipur, at village Bharenga. The national highway is along the northern boundary of the site. The net area of the site is 55.52 ha., from which 1.8 ha. of land is selected for developing administrative building of NIT Raipur.
Figure 5.2 - Site The site is polygonal in plan measuring 137.2 acres. The site has been provided by government to National Institute of Technology, Raipur to develop a new campus..
59
A 12 meter wide internal city road flanks the south-east boundaries of the site. The site being contiguous to the already developed areas of the city, it would not be difficult to introduce municipal services in the project area.
Topology:
The site is flat with gentle slope towards south.
Geology & Soil Characteristics:
The site has top strata of evenly deposited muroom followed by black cotton soil. The soil comprises soft, expansive clay with some amount of organic content.
Climate: Raipur is located on latitude 21014‘ & longitude 81034‘ E & is at 296 meter above near sea level. The major climate factors affecting the nature of built form are solar radiation ambient temperature, relative humidity, prevailing wind and rainfall. The overall climate of Raipur can be termed as hot dry.
Temperature: The annual mean maximum temperature in May is 46.40C & the mean minimum temperature in December is 13.20C.
Wind direction: Predominant wind direction is south-west and post monsoon & winter direction is north-east.
Humidity: Relative humidity during monsoon season is above 75% and during winter season is below 40%. Rainfall: The average annual rainfall in the area is generally around 1400 mm. Rains are predominant during July & August. On an average there are 61 rainy days in a year. The Raipur District receives 87.1% of the total rainfall from the southwest monsoon 60
during June to September. The winter – rainfall accounts for 9% of the total rainfall. During the Monsoon the maximum rainfall occurs during the month of August where mean monthly rainfall was recorded at 363.7 mm. In monsoon season, the mean annual rainfall is 1332 mm.
61
CHAPTER 6 DESIGN APPROACH
62
The concept aims at developing plan form of a building to integrate the three basic elements of climate i.e. light, air and water into the built environment. These three elements of nature, upon their integration into the built form, have their functional as well as aesthetical impact. Their functional role is much crucial in present situation as a modern building is not only amongst the worst polluter of climate but also the largest consumer of energy.
6.1 Intuitive approach - Intuitions are the thoughts and preferences that come to mind quickly, in response to a particular prevailing condition, without much reflection upon the mathematical data or analytical calculations. When designing a building, a designer does not starts with all the analytical data that is available, but the designer follows some intuitions to develop a form, best suited to the local climatic conditions, required spatial organization, functional suitability, development of form and aesthetical appeal. Chhattisgarh is a landlocked state at the heart of India, having ―hot dry and composite‖ climatic conditions. The challenges in designing for hot dry and composite climate are: — heat is welcome in winters but avoidable in summer; wind is welcome during humid months but avoidable during winters and hot summers. The major factors that affect a climate responsive design could be identified as – 1. Shape
2. Orientation
3. Heat
4. Air
5. Water
6. Light
Following is an example showing the application of above stated factors with intuitional thumb-rules in developing a form for climate responsive administrative building. 6.2 Shape – Shape of any building develops from a base form. One basic criterion for selecting the
S/V ratio – The Surface area to volume ratio is three dimensional form of perimeter to area ratio and is an important factor in determining heat gain and heat loss through building fabric
base form is surface area to volume ratio (s/v ratio). It is based on the concept that different geometric shapes with same volume have different surface areas. This ratio is particularly important in the cases where climatic intervention is crucial factor in designing. The final building form evolves from this conceptual base-form. A building form with low surface area to volume ratio gains lesser 63
heat during summers and daytime and similarly loses lesser heat during winters and night. Low s/v ratio is considered optimal for hot dry and composite climates as it reduces the heat gain and heat loss, which in turn reduces the cooling and heating load of building (Givoni, 1994). The s/v ratio indicates thermal performance of basic shapes rather than complex ones. The most compact orthogonal building would be a cube (Fig.-6.1). But for day lighting and ventilation, large areas exposed to external surfaces are considered good (Behsh, 2001). Hence cube is elongated to increase its surface area and form a cuboid, which is a rectangle in plan (Fig.-6.2). The compromise made with the thermal performance of the external envelop can be compensated by using insulating material in
Minimum surface area reduces heat transfer
Increased surface area greater heat transfer
Figure 6.1- comparing the surface area external fabric. The efficiency achieved through proper day lighting and ventilation by increased surface area is an additional advantage. The thermal performance could be adjusted by proper orientation of building block. N W
E S
Figure 6.2- basic plan shapeform, the next step is to orient the block. In 6.3 Orientation – After deciding the base northern hemisphere, north facade of the building does not receive any direct solar radiation, whereas southern façade receives direct radiation in winter but very little in summer. Also day light received from north is considered best as light from north is diffused light which lacks glare. Hence longer façade should be oriented towards north— N W
Figure 6.3 - Orientation
E S
south (Fig.-6.3). East and west walls receive maximum solar radiation, especially when the sun is low in altitude. Solar gain on west and south-west part can be particularly troublesome as its maximum intensity coincides with hottest part of the day (Brown, 2001). Therefore, shorter facade of the building shall face east—west direction. 64
To assimilate the climate into the built environment, it is imperative to bring the light, air and water into the building so that inhabitants get to feel these elements not only from N W
E S
Figure 4 - Courtyard external facades but also from inside the building. Courtyard (Fig.-6.4) not only brings the natural environment inside but also controls the internal environment and serves the need of the inhabitants. It functions as a convective thermostat and gives protection from extreme effects of hot summers and cold winters. It also creates moods with varying degree of lights and shades and with them the ambience of abode.
Now, there is a rectangular block facing north-south, with central opening i.e. courtyard. To incorporate light, air and water, it is required to further develop the plan form. Firstly, dividing the existing block into four smaller blocks and modifying each block in such a way so as the modified form of each block serves a specific purpose (Fig.-5). N W
E S
Figure 6.5 – Dividing the basic shape into four corner blocks Objectives for further modification of each block are1) To minimize solar radiation. 2) To bring air into building and allow it to pass through the fabric, preferably after humidification. 3) To place a water body in windward side, so that it serves functionally and helps in convective cooling of the building. 4) To bring in maximum north light into work areas. 6.4 Heat – Solar radiations from west and south-west direction is most uncomfortable and troublesome as the radiation intensity from these directions is maximum when the day is most heated. To minimize these radiations, north western block is removed and southwestern block is inclined with shorter façade facing south west (Fig.-6). As a result, only 65
N W
E S
Figure 6.6- Inclining south-western block and removing north-western block to minimize heat gain. small surface receives direct radiation and remaining faces receives lesser radiation. This further reduces the heat gain into the building. Smaller face that receives direct radiation can be insulated using hollow blocks or cavity walls with additional screen walls. Besides, these spaces can be used for non conditioned uses as toilets, stairs, stores etc. that act as buffer between habitable areas and uninhabitable areas. 6.5 Air – Air movement is a crucial factor for human comfort. To bring the air into the structure, the most important thing is to know the prevailing wind direction for the local area, which, in case of Raipur, is from south-west (Fig.-6.7). To use this wind, providing an opening in the southern facade is not enough. Along with the south western block, that deflects the air towards the building, a protrusion of south-eastern block is required to trap this air. This creates a funnel with wide mouth inviting huge volume of air and narrow rear end — pressurizing the air captured, thereby creating a high pressure zone. The courtyard, being under low pressure, attracts the pressurized air, which ventilates the premises by Venturi effect. To allow cross ventilation, a gap between northern and eastern block is left (Fig.-6.8).
VENTURI EFFECT – Venturi effect occurs when two building blocks are placed at an angle to each other creating a funnel with narrow opening. Wind channeling through the opening are accelerated to high speed.
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Figure 6.7 – Prevailing wind direction from south-west.
Figure 6.8 – Adding and subtracting masses to catch wind.
6.6 Water- Aesthetically, water anywhere around the building or all around the building looks visually pleasing. But from functional point of view in hot-dry and composite climate, its placement becomes crucial. In case of Raipur, the wind coming from southwest is mostly hot and dry and south west portion is also most heated part of the building. Therefore, south-west corner is correct location for placing any water body (Fig-6.9). This water keeps evaporating, cools and humidifies the in-flowing hot dry wind, before it enters
Stilted south-west block
Courtyard
Water body
Wind flow
Figure 6.9 – Adding water body to south-west.
Figure 6.10 – Section showing air movement through stilted block
the confinements of the structure. South western block could be stilted to stretch water body into the courtyard and also allow air to pass through from under the stilted block (Fig-6.10). 6.7 Light – Most favorable natural light for better working condition in interiors is diffused north light (Lechner, 2009). Providing longer north facade and courtyard at centre allows ample daylight from both, exterior façade as well as interior courtyard facing facades. For maximum north light, northern and eastern blocks are provided with openings on north face. These blocks can be the most occupied work area as these are least heated blocks with maximum north exposure. Northern facade is further modified form being straight to ‗U‘ shaped, resulting in increased available window area (fig.-6.11). 67
Figure 6.11 – Modifying Northern and Eastern blocks, to harness north light
Additionally shape of northern blocks on each floor is kept different which allows creating voids in façade, allowing for cross ventilation and penetration of north light into internal corridors (fig.-6.12).
N W
E S
Figure 6.12 – ‗U‘ shaped northern blocks, different shapes on each floor
Eastern blocks are modified as north-south oriented linear blocks, placed behind each other at different levels, southern block being highest. This provides longer northern facades to all blocks for light and placing them on levels ensures ample light even to the lowest floor of southernmost block (fig.-13).
Figure 6.13 - Eastern blocks, height increasing backwards
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6.8 Miscellaneous – Some additional measures, like concept of mutual shadowing is applied on south western blocks. It can be done by sub dividing south western block into smaller blocks and orienting them in such a way so as shadow of one falls on the other. This further helps in reducing the surface area exposed to direct solar radiation. Open courtyard at centre can be partially sheltered by bamboo trellis that allows filtered light to pass through.
Figure 6.14 – Conceptual view from North-East corner
Figure 6.15 – Conceptual view from South-East corner
Intuitively, a form catering to a specific climatic need can be developed using some basic guidelines. Step by step development of form tells about ‗how to do.‘ Next step would be to find out ‗how much to do‘, i.e. analytical methods. Calculations will require local data of solar angles, wind direction, wind speed, rainfall, shapes and sizes of openings and fenestrations. There are simulative tools available to analyze the achieved thermal performance of the building. This allows further modifying and fine tuning the design to achieve desired comfort levels. Similar tools for calculating day light integration into the building are also available. If initial intuitive approach for development of form is proper, implementation of analytical data into the design becomes easier and asks for lesser modifications on the form initially developed.
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CHAPTER 7 SPECIAL STUDIES
70
7.1 ORIENTATION In solar passive buildings, orientation is a major design consideration, mainly with regard to solar radiation, daylight and wind. The orientation of the building should be based on whether cooling or heating is predominant requirement in the building. The amount of solar radiation falling on a surface varies with orientation. In tropical climate zones for example, North Orientation receives solar radiation for a very brief time period, and the intensity of radiation is minimum. Thus in tropical climate like India long facades of buildings oriented towards north— south are preferred. East and West receive maximum solar radiation during summer. South orientation receives maximum solar radiation during winters. Orientation also plays an important role with respect to wind direction. At building level, orientation affects the heat gain through building envelope and thus the cooling demand, orientation may affect the daylight factor depending upon the surrounding built forms, and finally the depending upon the windward and leeward orientation fenestration could be designed to integrate natural ventilation. Electric lighting and mechanical air-conditioning for cooling are the largest energy consumers in commercial buildings with high internal loads. Where site conditions permit,\landscaping or other shade structures to reduce the amount of sun on the building is the most effective method of solar control. Peak solar cooling loads are greatest through southwest- and west-facing windows and walls; solar loads from windows and walls facing other directions are smaller and easier to control. It is important to evaluate the shading opportunities of existing and future buildings on neighboring lots.
Where site conditions permit: •Locate the building toward the southwest, south, or west sides of the site to provide shade for lower floors from neighboring buildings. •Orient the building with the short wall facing west or southwest for the least solar gain in the summer. •Place service cores or opaque stairwells at the southwest or west ends to buffer interior spaces from afternoon solar gain.
71
•Orient the building with the long side east-west for highest winter gains and lowest summer gains. Southeast or southwest orientation can capitalize on morning or afternoon solar gains respectively without major losses in performance.
7.2 DAY LIGHTING Day lighting has a major effect on the appearance of space and can have considerable energy-efficiency implications, if used properly. Its variability and subtlety is pleasing to the occupants in contrast to the relatively monotonous environment produced by artificial light. It helps to create optimum working conditions by bringing out the natural contrast and colour of objects. The presence of natural light can bring a sense of well being and awareness of the wider environment. Daylighting is important particularly in commercial and other non-domestic buildings that function during the day. Integration of daylighting with artificial lighting brings about considerable savings in energy consumption. A good daylighting system has a number of elements, most of which must be incorporated into the building design at an early stage. This can be achieved by considering the following in relation to the incidence of daylight on the building. ■ Orientation, space organization, and geometry of the space to be lit ■ Location, form, and dimensions of the fenestrations through which day- light will enter ■ Location and surface properties of internal partitions that affect daylight distribution by reflection ■ Location, form, and dimensions of shading devices that provide protection from excessive light and glare ■ Light and thermal characteristics of the glazing materials. Daylight integration is an important aspect of energy-efficient building design, and most of the case studies covered in this book have innovative daylighting strategies. ■ Floor plans with relatively narrow wings, ensure that most interior spaces have good access to natural light and winds.
72
■ Redirecting daylight with light shelves, prismatic glazing and other reflective systems can extend naturally lit interior space upto 10 mtrs. Deep. ■ Limit the maximum distance of workstations from the building exterior to 6-7 mtrs. To ensure good views to most of the occupants ■ Useful daylight from typical windows can only reach 6-7 mtrs. Into spaces with 3mtrs. Floor to ceiling heights, floor plans deeper than ~ 15 mtrs. Will require constant electric lighting.
7.3 SHADING DEVICES:Effect of angle of incidence To simplify the lengthy calculation, the concept of solar gain factor (@)has been introduced which expresses the proportion of the total heat admitted by a window by whatever means.the value of this for different angle of incidence can be read from graph given and the total incidence is to be multiplied by this single value
External shading devices
Figure 7.1 External shading devices
Solar azimuth and altitude The position of the sun is generally given as an azimuth and altitude angle:
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Azimuth represents the horizontal angle of the sun relative to true north. This angle is always positive in a clockwise direction from north when viewed from above, and is usually given in the range 180Ñ° < azi < 180°. Altitude represents the vertical angle the sun makes with the horizontal ground plane. It is given as an angle in the range 0Ñ° < alt < 90°.
Figure 7.2 - Sun position in the sky is typically given as an azimuth and altitude angle.
The sun paths at various dates are shown by group of curves extending from east to west (the date lines) which are intersected by short hour lines. The series of concentric circle establish a scale of altitude angles and the perimeter scale give the azimuth angle. From these two angle the sun position to the wall surface of any orientation (thus the angle of incidence) can be established.
Angle of incidence THE
HORIZONTAL COMPONENT OF THE ANGLE OF INCIDENCE
(§) will be the
difference between the solar azimuth and wall azimuth if ,the wall is facing west (270) § =270- solar azimuth The vertical component is the same as the solar altitude angle itself(y) The angle of incidence (β)i.e. the angle between a line perpendicular to the wall and the sun direction. Can be found bye the spherical cosine equation cos β = cos § x cos y
Shadow angles 74
Shadow angles can be calculated for any time if the azimuth and altitude of the sun are known. Horizontal shadow angle (hsa)( §) charectrises a vertical shading device andit is the difference between the solar azimuth and wall azimuth ,same the horizontal component for the angel of incidence.
Figure – 7.3 Horizontal shadow angle
Vertical Shadow Angle (VSA) (є)
Characterizes horizontal shading device a long horizontal projection from wall, and it is measured on a vertical plane normal to the elevation considered The distinction between solar altitude angle(y)and vertical shadow angel must be clearly understood . the first describe the sun position in relation to the horizon, the second describe the performance of the shading device .numerically the two coincide (y = є) when ,and only when, the sun is exactly opposite the wall considered(i.e. that when solar azimuth and wall azimuth angel(ω) are the same when α= w)when the azimuth difference § =0 for all other cases ,that is when the sun is sideways from the perpendicular the vertical shadow angel is always larger than the solar altitude angel for which it would be still effective є < y the relationships expressed as Tan є = tan y x sec §
tan VSA= (tan (altitude) X sec (HSA))
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Shade Dimensions These two angles, HSA and VSA, can then be used to determine the size of the shading device required for a window. If the height value refers to the vertical distance between the shade and the window sill, then the depth of the shade and its width from each side of the window can be determined using relatively simple trigonometry.
Shade Depth The depth of the shade is given by: depth(d) = height (h) / tan (VSA) The width is given by: width (w) = depth (d) X tan(HSA) The width simply refers to the additional projection from the side of the window. Exactly which side is a matter of the time of day and which side of the window the sun is on.
Rules of the thumb The table below indicates the most appropriate type of shading device to use for each orientation in the northern hemisphere. These are guidelines and, of course, there are many variations to these basic types.
Orientation
Effective shading
North (pole- facing)
Fixed horizontal device
East or West
Vertical device/louvers (moveable)
South
(equator-
Fixed horizontal device
facing)
A window facing south direction should be shaded with a horizontal shading device and any vertical device is preferred in low altitude sun to give appropriate horizontal shadow angle. Whereas, it is preferred a long horizontal projection or vertical shading device in west and east directions. 76
7.4 PASSIVE COOLING OF BUILDINGS Cooling of building by passive system can be provided through the utilization of several natural heat sink : the ambient air , the upper atmosphere, and the under surface soil. Such cooling system include:
Comfort ventilation: Providing direct human comfort by natural
ventilation, mainly during day time hours. Nocturnal ventilative cooling: Lowering the indoor day time temperature by ventilating the building at night. Radiant cooling: utilizing the process of nocturnal long wave radiation to the sky. Indirect: Evaporating cooling of the building by roof ponds and wetted conductive impermeable walls. Soil cooling: Utilizing the soil as a cooling source for building.
Ventilation requirements Ventilation has three function, which require different level of airflow through the building: 1. Maintaining acceptable indoor quality by replacing indoor air, vitiated in the processes of living and occupancy ,with fresh outdoor air. This function of ventilation is needed in all climate but is of intrest mainly in cold climates, and also in air conditioned buildings in all climate type. 2. Providing thermal comfort in warm environment by increasing convective heat loss from body and preventing discomfort from excessively moist skinthrough higher airspeed over the body (discomfort ventilation). 3. Cooling the structural mass of the building during the night and utilizing the cooled mass as a heat ―sink ― during the following daytime hours in order to maintain the indoor temperature well below the outdoor level(nocturnal ventilative cooling.) The physical forces generating ventilation 77
Ventilation, mainly the flow of outdoor air through a building, occurs when opening are available at point exposed to different levels of air pressure. Such pressure gradient (or pressure heads) can be generated by two forces: (a) Temperature difference between indoors and outdoor (thermal ,or thermosyphonic force) (b) Wind flow against the building (wind pressure force) Features affecting ventilation The main design features which affect the indoor ventilation conditions are Type of building Orientation of the building, especially the openings, with respect to wind direction. Total area of opening in the pressure and suction region of the building‘s Envelop. Type of window and detail of their opening. Vertical location of opening. Interior obstructions to airflow from the Inlet to the outlet openings. Specialized details which direct the air into the building.
Direct Gain - Cooling Cycle It is vital to provide cross-ventilation in a building in summer to not only supply fresh air but also: Give instantaneous cooling whenever the inside temperature is higher than the outside one; Remove overnight the heat stored in the building fabric during the day commonly referred to as night purging; and
Provide the feeling of cooling on the skin by accelerating its evaporative
cooling (this can also be provided by the use of fans, particularly ceiling fans)
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Solar shading should be configured over the northern windows to exclude access to most summer sun to the interior spaces. Additionally, it is desirable to provide extra shading by a pergola planted with deciduous vines, or adjustable (fabric or metal) blinds on the northern windows to protect them from heat gain in unseasonably hot weather occurring in early autumn or late spring. As the outside air temperature increases during a summer day the inside air temperature is modified by the walls and floor absorbing heat from the air. Additional efficiencies can be introduced into the direct-gain cooling cycle by:
Fostering vegetation near the southern-side openings used for ventilation
- if these plants are watered in summer the air passing through them will be partly cooled before entering the internal space;
Planting deciduous trees or vines on the northern and western sides of a
building to provide shade in summer and admit sunlight in winter;
In sub-tropical and tropical humid zones and in humid areas of other
zones, adopting a design with a ventilated space between the roofing and the ceiling;
Adding suitable insulation under the roofing material.
Table 7.1- R and C values of different materials
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7.4 BUILDING MATERIALS Buildings consume vast amounts of our resources and threaten the ecological systems that support life, from the ozone layer to the world's forests. Changing the way we build has become imperative. Manufacturing the cement for the 55 yards of concrete 'm the foundation generates on the order of 20,000 Ibs. of C02 emissions. Commercial buildings are resourceintensive to build. Over their operating lives, most buildings consume many times the energy used during [[construction Using the most environmentally sound materials is an important step in the overall goal of improving the environmental performance of any building. The building industry is beginning to respond to these concerns. New products .and materials are being developed that use resources more efficiently. Manufacturing processes have started to be redesigned/upgraded to reduce waste and pollution. New and old products made from recycled materials are available, but these have to be furthered. Concern over toxins entering the environment is being reflected in less toxic materials. Construction methods have to be developed to increase efficiency and reduce job-site waste. In some areas where the industry has evolved over the past few years energy efficiency standards have increased. But still lot of areas are still not evolved. It has to be even/ones continuous effort in struggle to save the planet by making sustainable developments.
One of the paths will be to become more and more selective and
resource efficient in future in terms of the materials that we use -materials that are renewable, biodegradable, have low in embodies energy, and locally produced will further this green movement
Environmental Criteria For evaluating any material the environmental impact of the material has to be considered for the complete life cycle of the material including harvesting, manufacturing, distribution, installation, operations, reuse, or disposal. 80
The Challenges in defining ‘what is Green?’ Many of these criteria used to select products are, by nature, subjective, and a product may perform well under one criteria but poorly under another. Tradeoffs between different criteria are inevitable. Frequently these criteria are in conflict. For example, engineered wood products use trees more efficiently than sawn lumber, but they also contain a lot of glue and resins that can create indoor air quality problems and make the products harder to recycle. Concrete is extremely durable and can provide energy saving thermal mass, but the production of cement is energy-intensive and contributes significant amounts of carbon dioxide to the atmosphere. The standards and thresholds by which we weigh now, have to evolve and continuously get upgraded over time. Even in the greenest of projects it is likely that many products will be used that are not themselves green - but they are used in a manner that helps reduce the overall environmental impacts of the building. A particular window may not be green, but the way it is used maximizes collection of low winter sunlight and blocks the summer sun. So even a relatively conventional window can help make a house green. Creating a green building means matching the products and materials to the specific design and site to minimize the overall environmental impact. Green products in isolation hold not much value, as Green products could be used in bad, non judicious ways that result in buildings that are far from environmentally responsible. In a well-though-out building design, however, substituting green products for conventional products can make the difference between a good building and great one.
Source of Material a. Renewable source–Rapidly renewable sources e.g. wood from certified forests b. Reuse of Waste-Salvaged products –e.g. old plumbing, door frames c. Recycled contents –agriculture/ industrial waste e.g. Bagasse Board
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Embodied Energy Scalar total of energy input required to produce the product including transporting them to the building site
Figure 7.4 – Embodied energy of different materials
Local Availability Transportation Cost–For materials not available locally the transportation cost can form a significant part of its embodied energy.
Reduce Pollution Air Pollution-Use of materials with low VOC emissions e.g. Cement Paints Land Pollution-Materials that reuse waste that would otherwise have resulted in landfill. e.g. Flyash Bricks Water Pollution–Materials that prevent leaching.
Performance Durability & Life Span-Material that are exceptionally durable, or require low maintenance e.g PVC pipes. Reduce material use-These are energy efficient and also help reduce the dead load of a building. e.g. Ferrocement
Energy Conservation Materials that require less energy during construction e.g. precast slabs 82
Products that conserve energy–e. g. CFL lamps. Materials that help reduce the cooling loads-e.g –aerated concrete blocks. Fixtures & equipments that help conserve water e.g. Dual flush cisterns
Recyclable Reuse or Recycle as different product e.g. steel, aluminum. Biodegradable –that decompose easily e.g wood or earthen materials.
Recommended alternatives Roofing and ceilingAlternatives to Ferrous / non-ferrous sheets, tiles, thatch a.
Fibre Reinforced Polymer Plastics instead of PVC and Foam PVC,
Polycarbonates, acrylics & plastics b.
Micro Concrete Roofing Tiles
c.
Bamboo Matt Corrugated Roofing Sheets
Tiles for interiors a.
Terrazzo floor for terraces and semi covered areas
b.
Ceramic tiles (non-vitrified)
c.
Mosaic Tiles/ Terrazzo Flooring
d.
Cement Tiles
e.
Phospho-Gypsum Tiles
f.
Bamboo Board Flooring
Windows, Doors and openings – Alternatives to Timber and Aluminum / Steel frames a.
Ferro cement
b.
Pre-cast R.C.C. Frames/ Frameless Doors
c.
Hollow recycled steel channels and recycled Aluminum Channels and
Components Shutters and Panels – Alternatives to timber, plywood, glass, aluminum a.
Red Mud based Composite door shutters, 83
b.
Laminated Hollow Composite Shutters
c.
Other wood alternatives
Wood •
Renewable timber from plantations or timber from a government
certified forest / plantation or timber from salvaged wood •
Plywood should be phenol bonded and not urea bonded
•
Use of MDF Board
•
Instead of Plywood: Bamboo Ply/Mat Board/ Fibre Reinforced Polymer
Board/ Bagasse Board /Coir Composite Board /Bamboo mat Veneer Composite. •
Use of Mica Laminates and Veneer on Composite boards instead of
natural timber.
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