Globally buildings are responsible for at least 40 % of energy used, 42 % of the global water consumption and 50% of the Global consumption of raw materials during manufacturing, construction and operational period of buildings. India too faces the environmental challenges triggered by the construction sector, which pose major threats in terms of air pollution, greenhouse gases, water pollution, solid waste and CFC generation.
Buildings are major consumers of water during construction and operation (for occupants, cooling and landscaping). With per capita availability of water supply reducing and also because of its critical importance for agriculture and allied needs, it is becoming important to optimise and reduce the usage of water in buildings. There is a huge potential of generating water through wastewater treatment for various applications. As per the central pollution control board report on the status of wastewater generation only 27% of wastewater generated is recovered from the 9.51 BCM generated in Class 1 and Class 2 cities in India.
Management of construction & demolition waste as well as solid waste generated by occupants of buildings pose a major environment and health challenge. Waste generated through construction industry accounts for 25% of the total produce. Also the absence of segregation of waste and mindless dumbing of mixed waste has lead to life threatening landfill saga. Landfill gases and fires along with effects of direct toxicological action of chemicals present in waste sites on human health are creating problems ranging from general weakness, headaches, sleeplessness to more serious ones like low birth weight, birth defects, certain types of cancers etc.
“Heat Island” effect, which is the result of massive and dense urbanisation, is leading to uncontrolled damaging environmental effects, which pose detrimental health effects directly. This also leads to our demand on air conditioning which in turn puts heavy demand on energy consumption and in turn leads to more generation of greenhouse gases. This brings us back to design and plan buildings in tandem with natural surroundings which are conducive to local climate conditions, harness the power of natural elements and are sensitive to environment – in short Green Buildings.
Green Buildings – An urgent requirement: As enumerated above, the green building solutions should not merely be viewed or adopted as a Band-Aid strategy, in reality they are to be adopted as serious design strategies which require looking into account various parameters like:
- Site planning
- Building envelope design
- Building system design (HVAC, lighting, electrical, water heating)
- Integration of renewable energy source to generate energy onsite
- Water management & wastewater management
- Selection of Eco-friendly, ecologically sustainable materials
- Indoor environment quality (thermal comfort, visual comfort and air quality) etc.
Green Buildings have evolved as a mathematical and pragmatic science with the help of assessment/evaluation protocols providing benchmarks for certain essential Key Performance Indices. The performance benchmarking and pre-assigned criteria have been enumerated under different green building rating systems as developed & followed by different nations.
UK- BREEAM (Building Research Establishment’s Environment Assessment method) – 1990 pioneered the Green Building Rating movement.
Hong Kong – HK-BEEM (The Hong Kong Building Environmental Assessment Method) 1996
USA – LEED (Leadership in Energy & Environmental design) 1998
Canada – GREEN GLOBES – 2000
INDIA- IGBC (Indian Green Building Council) Rating – 2001
JAPAN – CASBEE (Comprehensive Building System for Environmental Efficiency) 2001
Australia – GREEN STAR – launched by GBC Australia in 2003
INDIA – GRIHA (Green rating for Integrated Habitat Assessment) 2005