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Buildings for Sustainable Development

An overview on

Buildings for Sustainable Development (BSD) This is the downloadable PDF, providing an overview on “Buildings for Sustainable Development�. It can be downloaded from the website www.bsd.civil.mrt.ac.lk, which has been developed as an e-learning module for the undergraduates of the Department of Civil Engineering, University of Moratuwa, Sri Lanka.

Contents 1. Introduction

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2. Why Buildings?

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3. What is Sustainable Development (SD)?

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4. Buildings against SD

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5. Buildings for SD

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6. Building Materials for SD

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7. Building Planning & Design for SD

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8. Building Construction & Maintenance for SD

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9. Building Use for SD

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Note: The website www.bsd.civil.mrt.ac.lk is an e-learning tool for the undergraduates of the Department of Civil Engineering, University of Moratuwa. Under the guidance and supervision of Professor Thishan Jayasinghe, Asitha Jayawardena authored the content of this website. Eng (Prof) Thishan Jayasinghe (thishan@civil.mrt.ac.lk), B.Sc. Eng. (Moratuwa), Ph.D. (Cambridge), C.Eng, MIE(SL), graduated in 1987. He completed Ph.D. in 1992 and then worked at the Department of Civil Engineering, University of Moratuwa, for the last 14 years. His research interests are in the areas of tall buildings, masonry structures, long-span bridges and energy efficient buildings. Asitha Jayawardena (writer_asitha@yahoo.com), BSc Eng (Hons), MPhil, AMIE(SL), is a Communication Consultant. He has co-authored eight refereed research publications and published in the National press (English) 140 articles, 95 poems and a regular column. His interest is in Sustainable Development with a special focus on Buildings and Construction. May 2007

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1 Introduction We all need a variety of buildings to lead our lives – houses to live in, schools and universities to learn, hospitals to receive treatment, factories and offices to work in, cinemas, theatres and stadiums for enjoyment….. However, buildings can contribute against Sustainable Development, in turn adversely affecting our lives in the long run. Adverse impacts of such “unsustainable buildings” on sustainable development can be categorized as: Environmental degradation Energy consumption Natural resources depletion Environmental degradation

Energy consumption

Natural resources depletion Buildings against SD

Still, buildings can be made to contribute towards SD mainly through: Materials Planning & Design Construction & Maintenance Use

Building Materials for SD

Building Planning & Design for SD

Building Construction & Maintenance for SD

Building Use for SD Buildings for SD

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elearning-PDF-full This document covers the following: Why Buildings? What is Sustainable Development (SD)? Buildings against SD Buildings for SD Building Materials for SD Building Planning & Design for SD Building Construction & Maintenance for SD Building Use for SD

2 Why Buildings? We all need a variety of buildings – houses to live in, schools and universities to learn, hospitals to receive treatment, factories and offices to work in, cinemas, theatres and stadiums for enjoyment….. and the list goes on. In general, a building should serve its main purpose while providing its users with: Comfortable and safe living space Protection from adverse natural forces such as wind, rain and sunlight Protection from human and animal threats Privacy where it is needed

Comfort & safety

Space for living (house), working (workplace), education (school), enjoyment (cinema)…

Protection

Privacy

3 What is Sustainable Development (SD)? What is Sustainable Development (SD)? Gro Harlem Brundtland chaired the World Commission on Environment and Development, which led to the publication of the Brundtland Report in 1987. This report led to the first Earth Summit, in 1992 in Rio de Janeiro, and then to the landmark concept of “sustainable development”: “Development that meets the needs of the present without compromising the ability of future generations to meet their own needs”. www.bsd.civil.mrt.ac.lk

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Several other definitions of SD and Sustainability are: Sustainable Development: Development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Brundtland Report published in 1987 at World Commission on Environment and Development Sustainable Development: Achieving economic and social goals in ways that can be supported for the long term by conserving resources, protecting the environment, and ensuring human health and welfare. Technology Partnerships Canada (http://tpc-ptc.ic.gc.ca/epic/site/tpcptc.nsf/en/hb00422e.html) Sustainable Development refers to the wise use of resources within a framework in which environmental, economic and social factors are integrated. It is about maintaining and improving the quality of life while safeguarding the quality of life of generations to come. It involves a number of aspects of change such as social (e.g. housing quality, crime), economic (e.g. jobs, income), and environmental (e.g. air quality, resource conservation). National Curriculum in Action (http://www.ncaction.org.uk/subjects/geog/glossary.htm) Sustainability is an economic, social, and environmental concept. It is intended to be a means of configuring civilization and human activity so that society and its members are able to meet their needs and express their greatest potential in the present, while preserving biodiversity and natural ecosystems, and planning and acting for the ability to maintain these ideals indefinitely. Sustainability affects every level of organization, from the local neighborhood to the entire planet. Wikipedia (http://www.en.wikipedia.org/wiki/Sustainability) These definitions shed some light on SD. Economy

Sustainable Development (SD)

People

Environment

Development that is confined to economic development is not sustainable. What is desirable is Sustainable Development (SD), which takes an integrated approach blending economic, social and environmental dimensions. So SD takes into account the potential adverse effects of development on people and the environment. SD focuses on the quality of life of the future generations as well as the present generations. Turning to buildings in the context of SD. Buildings tend to contribute against SD. However, through careful planning, design, construction and use, buildings can be made to contribute to SD. This e-learning module shows how buildings contribute against SD (Buildings against SD) and summarizes how buildings can be made to contribute towards SD (Buildings for SD). Then it shows in more details how this can be done through: Materials (Building Materials for SD) Planning & Design (Building Planning & Design for SD) Construction & Maintenance (Building Construction & Maintenance for SD) Use (Building Use for SD)

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4 Buildings against Sustainable Development (SD) Buildings offer us a great service so that we can lead a comfortable, safe and healthy life – happily. However, buildings adversely contribute to sustainable development if they are planned, designed or used without considering their undesirable effects on people and the environment. Such undesirable buildings can be called “Unsustainable buildings�. In general, unsustainable buildings contribute to environmental degradation, energy consumption and natural resources depletion. Therefore, indirectly, such buildings adversely affect the health and comfort of its users, lowering their quality of life. Adverse impacts of buildings on sustainable development can be summarized as below: Environmental degradation Adverse impacts on bio diversity Adverse impacts on natural drainage paths & hydrological characteristics Adverse impacts on water cycle Promotion of natural disasters Environmental problems Indoor & outdoor air pollution Ground, air and water pollution associated with waste mismanagement

Energy consumption

Natural resources depletion

Embodied energy in building materials Energy consumption for materials transport Energy consumption for achieving indoor thermal & visual comfort

Depletion of raw materials Depletion of non-renewable energy sources

Buildings against SD Environmental degradation Adverse impacts on bio diversity Adverse impacts on natural drainage paths & hydrological characteristics Adverse impacts on water cycle Promotion of natural disasters Environmental problems Indoor & outdoor air pollution Ground, air and water pollution associated with waste mismanagement Energy consumption Embodied energy in building materials Energy consumption for materials transport Energy consumption for achieving indoor thermal & visual comfort www.bsd.civil.mrt.ac.lk

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elearning-PDF-full Natural resources depletion Depletion of raw materials Depletion of non-renewable energy sources Now, let’s consider in more detail the adverse impacts of buildings on sustainable development: Environmental degradation: Adverse impacts on bio diversity: Vegetation and habitats of other living beings are adversely affected when ground is cleared for the construction of buildings. Some of these living beings are essential for the well being of the human beings. Adverse impacts on natural drainage paths & hydrological characteristics: Arrival of a new building to a particular environment alters the existing natural drainage paths, causing various problems ranging from soil erosion to flash floods. Adverse impacts on water cycle: A new building covers the bare ground that previously allowed rainwater to seep into the earth, recharging the groundwater. Insufficient recharging of the groundwater disturbs the water cycle, causing problems such as water shortages in certain times of the year. Promotion of natural disasters: Disturbances to natural drainage paths and to the water cycle lead to natural disasters such as flooding and landslides. Environmental problems: Excessive extraction of natural resources for building construction has caused several environmental problems. Salt-water intrusion to rivers, soil erosion and riverbank collapses due to excessive sand mining for construction in rivers are examples. Indoor and outdoor air pollution: Buildings contribute to air pollution – both indoors and outdoors. Toxic finishing materials causes indoor air pollution. Removal of vegetation contribute to outdoor air pollution. Vegetation uses up carbon dioxide for photosynthesis and releases oxygen. Ground, air and water pollution associated with waste mismanagement: Haphazard dumping of waste generated during construction and use of a building contributes to ground, air and water pollution. Energy consumption: Embodied energy in building materials: Production of certain types of building materials requires high inputs of energy, consuming large amounts of fuels (e.g., cement, steel and clay bricks). Energy consumption for materials transport: Transportation of building materials from production centers to building sites consumes energy. Energy consumption for achieving indoor thermal and visual comfort: When thermal discomfort occurs in buildings, occupants and users use active techniques such as fans and air conditioners to achieve acceptable thermal comfort levels. When visual discomfort occurs in buildings during daytime, occupants and users use artificial lighting during daytime. Use of active techniques for thermal comfort and use of artificial lighting during daytime consumes energy. Use of artificial lighting during nighttime is unavoidable. Natural resources depletion: Depletion of raw materials: Natural resources used as raw materials for manufacturing building materials have developed after undergoing natural processes for millions of years. Consumption of these resources at a fast rate will deplete the resources. Examples include limestone for cement making and iron for steel making. Depletion of non-renewable energy sources: Non-renewable energy sources such as oil, gas and coal have taken millions of years to develop. Their excessive use paves the way for depletion of these reserves fast and the future generations will face shortages.

5 Buildings for Sustainable Development Buildings can be made to contribute towards SD mainly through: Materials (Building Materials for SD) Planning & Design (Building Planning & Design for SD) Construction & Maintenance (Building Construction & Maintenance for SD) Use (Building Use for SD) How this can be done is summarized below:

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elearning-PDF-full Building Materials for SD

Building Planning & Design for SD

Environment friendly materials Locally available materials Materials desirable for indoor thermal & visual comfort Low embodied energy materials High strength materials Durable materials Affordable materials Recycled materials Materials extracted or produced using energy from renewable sources Materials extracted or produced using energy from waste fuels Non toxic materials

Avoid of environmentally sensitive locations for buildings Multi-storey preference Indoor thermal & visual comfort through a passive approach Minimize heat gains Facilitate ventilation Daylight for visual comfort during daytime Planning for future requirements Efficient structural systems Disaster resistance Permeability of ground around building Water detention sump Rainwater harvesting design

Building Construction & Maintenance for SD

Building Use for SD Use of operable passive elements to improve indoor thermal & visual comfort Organic gardening Intelligent management of waste generated from building use

Local techniques using manual labour Good quality workmanship Intelligent management of construction waste Timely maintenance

Buildings for SD Building Materials Environment friendly materials Locally available materials Materials desirable for indoor thermal & visual comfort Low embodied energy materials High strength materials Durable materials Affordable materials Recycled materials Materials extracted or produced using energy from renewable sources Materials extracted or produced using energy from waste fuels Non toxic materials Building Planning & Design Avoidance of environmentally sensitive locations for buildings Multi-storey preference Indoor thermal & visual comfort through a passive approach Minimize heat gains Facilitate ventilation Daylight for visual comfort during daytime Planning for future requirements www.bsd.civil.mrt.ac.lk

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elearning-PDF-full Efficient structural systems Disaster resistance Permeability of ground around building Water detention sump Rainwater harvesting design Building Construction & Maintenance Local techniques using manual labour Good quality workmanship Intelligent management of construction waste Timely maintenance Building Use Use of operable passive elements to improve indoor thermal & visual comfort Organic gardening Intelligent management of waste generated from building use How buildings can be made to contribute towards SD is now discussed in detail.

6 Building Materials for Sustainable Development Let’s consider Building Materials for SD. Desirable options with respect to Building Materials can be summarized as follows: Environment friendly materials Locally available materials Materials desirable for indoor thermal & visual comfort Low embodied energy materials High strength materials Durable materials Affordable materials Recycled materials Materials extracted or produced using energy from renewable sources Materials extracted or produced using energy from waste fuels Non toxic materials Let’s consider each option in more detail: Environment friendly materials Quarrying for raw materials and producing building materials has caused extensive adverse environmental effects. For example, excessive clay mining for brick making lowers soil productivity in nearby paddy land and promotes mosquito breeding. Excessive sand mining in rivers promotes flooding, riverbank collapses, and salt-water intrusion. Use of environment friendly materials can mitigate these problems. Locally available materials Because of the rising price of the conventional building materials, housing has become unaffordable to underprivileged communities. With the rising fuel prices, the transport cost continues to increase its contribution to the rising prices. Use of locally available materials is a sound solution to this problem. Use blocks cast by local businesses instead of “importing” blocks produced far away from the construction site. Among the other benefits of using locally available materials are decrease of fuel consumption for materials transport, reduction of harmful emissions during materials transport and thriving of small scale, local building materials businesses. Materials desirable for indoor thermal and visual comfort Selecting materials that are desirable for indoor thermal and visual comfort will lower the energy consumption for indoor thermal and visual comfort when the building is in use. For example, use clay tiles instead of cement fibre sheets as roof covering.

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elearning-PDF-full Low embodied energy materials Certain materials consume a large amount of energy during their manufacturing and extensive use of such materials increases energy consumption in the building materials industry. Cement, clay bricks and steel are examples. Where possible, use low embodied materials such as soil blocks and rammed earth because they do not consume large amounts of energy during production. High strength materials In buildings materials are used either for withstanding forces or for partitioning. With respect to withstanding forces, consider the example of concrete. The amount of material needed for withstanding a particular force is less with high strength concrete than with conventional concrete. The key benefit of high strength materials is the reduction of the consumption of natural resources as building materials. These materials also contribute to lower the energy consumption and emissions associated with quarrying and building materials production. Durable materials Use of durable materials delays or even eliminates the need for repair of buildings. While reducing the consumption of natural resources as building materials, durable materials contribute to lower the energy consumption and emissions associated with quarrying and building materials production. Affordable materials Shelter is a basic human need and making shelter affordable to a wider section of the society, especially to the underprivileged, is vital for sustainable development. Recycled materials Recycling offers an opportunity to make the maximum use out of the natural resources gone into a particular building material. Use of recycled materials contribute to reduce the consumption of natural resources as building materials and to lower the energy consumption and the emissions associated with quarrying and building materials production. Materials extracted or produced using energy from renewable sources Non-renewable energy sources such as oil and coal are limited, and they take millions of years to develop to energy-source status again. So they are fast depleting, as the rate of renewal is negligible when compared with that of consumption. However, renewable energy sources such as solar energy, wind energy and hydropower renew themselves and do not deplete with use. Moreover, use of nonrenewable energy causes harmful emissions while use of renewable sources is clean and environmentfriendly. Therefore, use of materials extracted or produced using renewable energy will lower the consumption of non-renewable energy resources and also reduce the associated emissions. Materials extracted or produced using energy from waste fuels Materials discarded as waste have energy embodied in them and these materials can be used as fuels in producing building materials. While offering a waste management solution, use of selected waste materials as fuels for building materials extraction and production lowers the energy consumption in the building materials sector. For example, waste plastics used for cement co-processing provides a waste disposal solution while lowering the consumption of conventional energy sources for cement production. Non-toxic materials Prolonged exposure to certain modern building materials (e.g., certain adhesives and coatings) causes health problems because they contain pollutants such as volatile organic compounds (VOCs). Avoid such modern materials and, whenever possible, prefer more natural materials. Innovative use of mud plasters is a good example.

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7 Building Planning & Design for Sustainable Development Let’s consider Building Planning & Design for SD. Desirable options with respect to Building Planning & Design can be summarized as follows: Avoidance of environmentally sensitive locations for buildings Multi-storey preference Indoor thermal & visual comfort through a passive approach Minimize heat gains Facilitate ventilation Daylight for visual comfort during daytime Planning for future requirements Efficient structural systems Disaster resistance Permeability of ground around building Water detention sump Rainwater harvesting design Let’s consider each option in more detail: Avoidance of environmentally sensitive locations for buildings Most, if not all, forms of life are important in ensuring a quality of life for humankind. Therefore, adverse effects on biodiversity will eventually negatively affect quality of our life. So avoid environmentally sensitive locations for construction of buildings, especially wetlands. Multi-storey preference Whenever possible, select building type as multi-storey as opposed to single-storey because multi-storey type offers sustainability benefits, such as: Compare a multi-storey building with an equivalent single-storey building (i.e., with same floor area). In the multi-storey building, the lower plot coverage provides more bare ground for seepage of rainwater into the ground, reducing the surface runoff to road. So its interference to the water cycle is less and it lowers the likelihood of flash flooding. When the two types are compared, the multi-storey type facilitates better a passive approach for indoor thermal and visual comfort when the building is in use. Among the key reasons for this enhanced passive performance are: Increased ground area for growing vegetation for creation of a thermally desirable microclimate Lower area of thermally most undesirable element (namely roof) when compared with an equivalent single-storey building Increased external surface area for provision of openings (i.e., windows) with thermally desirable orientation and appropriate area Indoor thermal & visual comfort through a passive approach In tropical climates, warm indoors causes the consumption of a large amount of energy for achieving thermal comfort through active means (e.g., fans, air-conditioners). Meanwhile, although the tropics enjoy the sun for half a day, daily, around the year, improperly planned buildings without due attention to daylight use requires active means (e.g., artificial lighting) to achieve indoor visual comfort during daytime. In order to eliminate, or at least lower this energy consumption, plan and design buildings that achieve indoor thermal and visual comfort by way of passive means (e.g., shaded openings with desirable orientation, use of daylight for indoor illumination during daytime). Key methods of a passive approach include: Minimize heat gains Facilitate ventilation Use daylight for visual comfort during daytime

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elearning-PDF-full Minimize heat gains Minimization of heat gains into the building is critical in achieving thermally comfortable indoor environment. Heat gains into the building are mainly two types: Heat finding into the building across the building envelope (i.e., roof and walls) by way of conduction Heat finding its way into the building by convection through openings (i.e., with outdoor air coming into the building) Direct or reflected solar radiation finding its way into the building through openings Radiant heat gains due to exposure of building to heated bodies (e.g., roads, other buildings) or excessive heating of elements of the building envelope, especially the roof Heat generated inside building (e.g., use of artificial lighting that gives out heat in addition to light) To lower the heat gain by way of conduction: Create a thermally desirable microclimate around the building using excessive vegetation. It will lower the outdoor air temperature, lowering heat gain by way of conduction. Maximize vegetation by innovative methods (e.g., roof garden, walls with vegetative surfaces such as ivy) Use thermally desirable wall materials that inhibit conduction (e.g., clay bricks, stabilized soil blocks or hollow cement sand blocks instead of solid cement sand blocks). To lower the heat gains by way of convection: Again, create a thermally desirable microclimate with excessive vegetation so that the outdoor air is cool To lower the heat gains by way of direct or reflected solar radiation: Provide openings facing shadable directions (i.e., facing north or south) and shade these openings with overhangs so that direct solar radiation does not find its way into the building. If openings facing east or west are unavoidable, provide only short openings and shade them with operable blinds, as overhangs will not be very effective. Grow vegetation (e.g. grass or, even better, shrubbery) immediately around building instead of rendering or floor tiles. Rendered or tiled surface immediately around the building will allow reflection of direct solar radiation into the building through the openings. However, vegetation will instead diffuse the solar radiation falling on them, lowering the amount of reflected solar radiation into the building. To lower radiant heat gains: Because of its upward orientation, the roof of a building in the tropics is exposed to the sun during the entire daytime throughout the year. However, a wall facing north or south is exposed to the sun only several months of the year throughout the daytime. And a wall facing east or west will be exposed to the sun only for several hours everyday throughout the year. So, in terms of orientation, the roof is thermally more undesirable than walls. Moreover, from the point of view of thermal properties, the roof is thermally more undesirable than walls. The hot roof will transfer heat to exposed bodies inside the building – including the occupants – by way of radiation. So: Minimized the area of roof (e.g., by way of multi-storey type) Use thermally more desirable roof materials (e.g., clay tiles instead of cement fibre sheets) Provide a ceiling below roof, preferably with ventilated attic space Provide insulation for the roof and the ceiling Paint the external surface of the building envelope (roof and walls) with a light colour (preferably white) so that the major component of solar radiation falling on the building undeveloped is reflected. To lower the heat generated inside building: Use daylight to illuminate indoors during daytime so that need for artificial lighting during daytime is minimized

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North/south facing opening

East/west facing opening

Solar radiation with high solar altitude so overhang is effective

Solar radiation with low solar altitude so a very long overhang is needed

Ground reflected radiation can enter across an opening well-shaded by an overhang

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elearning-PDF-full Facilitate ventilation In tropical climatic conditions, facilitation of natural ventilation is important because ventilation promotes: Conductive-convective heat loss from the human body Evaporation of the skin moisture from the human body, resulting in a physiological effect of cooling Structural cooling, paving the way for a cooler structure at the beginning of the next day Research studies have also found out that people acclimatized to warm humid climatic conditions for generations generally feel comfortable at relatively high indoor temperatures as high as 30oC when a sufficient air movement up to 1m/s is available. Moreover, ventilation improves indoor air quality. So, to promote ventilation indoors: Provide an adequate number of openings for each space (i.e., room) of building In a particular space, if possible, provide two openings on perpendicular walls Use night air for cooling Provide larger and more number of openings by way of a courtyard Daylight for visual comfort during daytime By utilizing daylight for indoor visual comfort during daytime, need for artificial lighting during daytime can be lowered or even eliminated. While saving electricity consumed by bulbs, such use of daylight contributes to lower the heat generated indoors by bulbs. So, to utilize daylight: Provide an adequate number of openings to allow daylight into the building. Paint with light colors (preferably white) the internal surfaces of roof/ceiling, walls and floor. Or use light color tiles for floor. Avoid tinted glasses for openings. Avoid blind walls. Proper planning for future requirements Plan the building properly considering the future requirements. Then changes or unplanned extensions to the building can be reduced so that materials and labour spent on such changes can be saved. Efficient structural systems The structural of a building resists the forces on it. An efficient structural system will resist these forces by consuming a smaller amount of materials, lowering materials consumption. Disaster resistance A building designed for resistance to a particular natural disaster (e.g., earthquakes, cyclones, tsunamis, flooding) will suffer less damage in the face of that particular natural disaster. Such design will lower the need for complete demolition or serious repairs, lowering material consumption for replacement or repair. Permeability of ground around building Extensively built up spaces in urban areas have blocked the rainwater from recharging the groundwater. So, following heavy, continuous rain, rainwater quickly runs into the roads, creating flashfloods. Therefore, it is important to keep as much garden area around the building bare so that rainwater seeps into the ground lowering the likelihood of flashfloods. Besides, it will support the functioning of the water cycle. Water detention pit In heavily built up areas (e.g., urban areas), inadequate area of bare ground makes rainwater find its way from gardens to the road, generating flashfloods. A water detention pit with brick-lined walls and an unlined bottom built in gardens will delay the flow of rainwater into the road, lowering the likelihood of flashflood generation. Rainwater harvesting design Rainwater running into the road causes many problems, including flashfloods. By way of rainwater harvesting design, rainwater can be used safely for flushing toilets and gardening. It will lower the demand for pipe-borne water and will reduce the water bill.

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8 Building Construction & Maintenance for Sustainable Development Let’s consider Building Construction & Maintenance for SD. Desirable options with respect to Building Construction & Maintenance can be summarized as follows: Local techniques using manual labour Good quality workmanship Intelligent management of construction waste Timely maintenance Let’s consider each option in more detail: Local techniques using manual labour Where possible, construct buildings using local techniques and manual labour. Local communities are usually skilled and familiar with local construction techniques and use of manual labour provides them with employment. Use of complicated techniques using machinery will require machinery transport to building site and/ or machinery use, causing emissions. A good example is onsite block making using manual labour instead of buying blocks from a distant source producing blocks using machinery. Good quality workmanship Good construction quality (especially durability) achieved through good quality workmanship will lower need for repairs and will thereby lower the consumption of natural resources as building materials for repairs. Intelligent management of construction waste Manage construction waste intelligently instead of dumping it haphazardly, polluting the environment. For example, demolition waste can be used for making blocks, lowering the consumption of natural resources as building materials and also the likelihood of pollution due to haphazard disposal. Timely maintenance Timely maintenance of building elements will lower the need for repair, lowering consumption of natural resources as building materials. For example, timely painting of exposed steel elements will lower the likelihood of corrosion.

9 Building Use for Sustainable Development Let’s consider Building Use for SD. Desirable options with respect to Building Construction & Maintenance can be summarized as follows: Use of operable passive elements to improve indoor thermal & visual comfort Organic gardening Intelligent management of waste generated from building use Let’s consider each option in more detail: Use of operable passive elements to improve indoor thermal & visual comfort Use operable passive elements appropriately to improve indoor thermal and visual comfort, lowering the need for active means. For example, open windows for enhanced ventilation and draw up and down the blinds provided to protect windows facing thermally undesirable orientations (i.e., east or west). Organic gardening Gardening offers several sustainability benefits: Gardening is very good for health and is considered as an effective reliever of stress commonly found among the modern society. Mini-scale agriculture, as is the case with gardening, is unlikely to need the use of chemicals such as pesticides and fertilizers, which are environmentally unfriendly and adversely affect biodiversity. Consumption of such chemical-free fruits and vegetables is good for health. Mass scale agriculture usually grows one type of vegetation in a large extent of land, hence adversely affecting the “balance of soil fertility”, eventually leading to productivity losses. Mini-scale

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elearning-PDF-full agriculture is likely to grow several types of vegetation in a small garden for home consumption, for example. Garden full of vegetation contributes to the desirable microclimate required for achieving indoor thermal comfort. Intelligent management of waste generated from building use When a building is in use, waste – both solid and liquid waste. Intelligent management of this waste contributes to natural resources conversation while minimizing adverse effects on the environment. Therefore: Adopt most preferred options of waste management hierarchy for solid waste: Avoid waste, Reduce waste & Reuse waste. These options will lower the consumption of natural resources as goods and materials in day-to-day use. Use biodegradable waste as compost for gardening. It will increase the productivity of soil for better gardening. Support initiatives for recycling and recovery (materials and energy) by patronizing relevant products and services and by source separation of waste where applicable. While lowering environmental pollution due to mismanagement of waste, such initiatives create wealth out of waste and lower the natural resources consumption for producing goods. Treat grey water (from shower, bath, kitchen) and reuse it for gardening/ flushing toilets. It will lower the demand for pipe-borne water.

EXAMPLES

Avoid waste

Reduce waste Reuse waste

Recycle waste

Recover energy/minerals from waste

Disposal by incineration

Use mugs instead of disposable cups Use both sides of paper

Use jam jars as toothbrush holders Recycle paper into more paper, insulation or packing material Recover energy embedded in plastics to fuel cement kilns Dispose of waste in a safe and environmentally sound manner

“Disposal” (storage) by land filling In the waste management hierarchy, the best option is “Avoid waste”. As you go down, the preference lowers and the least preferred is “Disposal of waste”.

Waste Management Hierarchy

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Buildings for Sustainable Development  

Buildings for Sustainable Development, a booklet for engineering students of Moratuwa University, Sri Lanka

Buildings for Sustainable Development  

Buildings for Sustainable Development, a booklet for engineering students of Moratuwa University, Sri Lanka

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