25-09-2012, 11:16 AM
Green Building- for Sustainable Development
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INTRODUCTION :
Shelter is one of the fundamental needs of human beings. The need to own a place for living is also seen in animals and birds. In the beginning of human civilization man used to live in caves and on trees, gradually he has identified materials suitable for construction like clay, stone and timber. Basic purpose of these dwellings is to protect man from weather and predators. These houses made way for larger inhabitations like castles, forts and palaces which had built in mechanism for providing sunlight and fresh air. As the time went on, man with his knowledge invented latest technologies and materials which helped him in construction of different types of buildings. These buildings and the materials used for construction brought rapid changes in the environment. Limitation of space, growth of population and rapid urbanization lead to community dwelling culture which increased problems like CFC emissions, insufficient ventilation, increase of waste materials during construction and maintenance of house arouse.
PLANNING AND CONSTRUCTION OF GREEN BUIDING:
It is very important for careful planning before a Green Building project is started. Though building green house does need to be expensive or time consuming, final choice of type of green building will depend on the space desired, home architecture, available site and costs. Green building should be located in such a place where there is maximum sunlight. The first choice of location is either south or south eastern side. Sunlight all the day is best for proper lighting of the house and growing trees like maple, oak, neem and tamarind can efficiently shade the Green building from intense late summer afternoon. Good drainage system is another important requirement for the site. The Green building should be built above the ground level so that rain water and irrigation water will drain in to the soil. Evolve strategies to stockpile top soil for landscaping purpose. Consider adopting measures such as temporary and permanent seeding, mulching, dykes, silt fencing, sediment traps and sediment basins where ever required. Open areas can be landscaped and paved areas can be developed with permeable paving. For impermeable surfaces like concrete surfaces direct entire runoff towards storm water collection pits.
WATER EFFICIENCY:
Reduction of water consumption and protection of water quality is other important factor for Green building. The conservation and protection of water throughout the life of a Green building can be accomplished by designing for dual plumbing that recycles water in toilet flushing. Waste -water may be minimized by using water conserving fixtures like ultra low flush toilets and low flow shower heads. Bidets may be used to reduce the usage of toilet papers, reduce load on sewers and increasing possibilities of reusing water on-site. Water treatment is a must for maintaining water quality. Usage of grey water for growing plants will also helpful for water conservation. There should be provision for rain water harvesting systems. Water efficient fixtures are to be used to minimize indoor water usage.
ENERGY EFFICIENCY :
Green buildings are also useful to reduce energy consumption. Higher performance buildings use less operating energy. Studies such as U.S. LCI Database Project(6) show buildings built primarily with wood will have a lower energy than those built with brick, concrete or steel(7). Usage of high efficiency windows and insulation in walls, ceiling and floors increase the efficiency of the energy envelope. Passive solar building design can also be used in low energy homes. Designers orient windows and walls, porches and trees to shade windows and roofs during the summer while maximizing solar gain in the winter(8). Apart from this proper window placement can provide more natural light and lessen the need for electric lighting during the day. Providing proper metering also saves energy. Solar water heating also reduces energy costs. Onsite generation of renewable energy through solar, wind, hydro or biomass energies can significantly reduce the environmental impact on the building.
MATERIALS EFFICIENCY :
Building material is another criterion that should be selected carefully for Green building. Materials like bamboo, straw, dimension stone, recycled stone, recycled metal and other products that are non toxic, reusable, renewable or recyclable can be used(9). Environmental Protection Agency EPA recommends using recycled industrial goods like coal combustion products, foundry sand and demolition debris of construction projects(10). Building materials are to be extracted and manufactured locally nearer to the building site to reduce the energy required for their transportation. Usage of green refrigerants (clorofluoro carbon free)is recommended.
IN DOOR AIR QUALITY :
Indoor Environmental Quality(IEQ) category in LEED standards (Leadership in Energy and Environmental Design) is the one which provides comfort, wellbeing and productivity of occupants of the Green buildings. The LEED IEQ addresses for the thermal quality, lighting quality and indoor air quality(11). Indoor air quality reduces volatile organic compounds and other air impurities like microbial contaminants. Properly designed ventilation is required for proper recirculation of clean air. Another important thing is the control of moisture accumulation leading to mould growth and presence of bacteria viruses by proper insulation. Exhaust systems are to be provided in kitchens and bathroom for clean air. Green architecture reduces waste of energy, water and materials used during construction. Recycling is the other important process by which there can be reduction of wastage.