We are developing with sky rocketing pace. We are loading our atmosphere with thousands of pounds of CO2 every year. To offset this CO2 , more trees need to be planted. As per the estimates, in US only, to offset the huge amount of CO2, trees need to be planted on 2.15 billion acres of land!!(The total land in US is 2.3 billion acres). So just planting trees is not at all enough.
Research and studies show that the Buildings have significant amount of contribution in polluting the environment. According to US Green Building Council’s study of Environmental impact of buildings (2007), Buildings in the United States contribute 38.9 percent of the nation’s total carbon dioxide emissions, (including 20.8 percent from the residential sector and 18.0 percent from the commercial sector), 39 percent of total energy use, 12 percent of the total water consumption, 71 percent of total electricity consumption.
The verge at which we have brought Mother Nature in our blind run of development is extremely critical and needs a complete green solution, which is ‘Green Building’.
Green Building refers to the incorporation of environment friendly and resource efficient processes at each stage of construction, right from site selection and designing to construction, operation followed by maintenance, renovation or even demolition. The endeavour is to seek minimum possible impact on environment.
The concept of Green Building concentrates mainly on two points:
· Increasing the efficiency with which buildings use energy, water and materials
· Reducing building impacts of human health and the environment, through better site selection, design, construction, operation, maintenance, and removal throughout the complete life cycle.
Going Green in Building constructions avails us many Environmental, Economical as well as Social benefits.
History and Components of Green building
The increase of fuel costs in 1970’s along with the concern for environment kindled the awareness and encouragement towards Green Buildings. Architects and ecologists started looking for solutions like reflective roofing materials, triple-glazed windows to achieve energy savings. But with the decrease of fuel prices, the Green movement was slowed down and did not receive much encouragement. It was later in early 90’s that the movement got kick start and awareness began to spread about need for sustainable buildings. An official Green home building program started in Austin, Texas in 1991. The movement has gradually gained momentum since then and we can now find significant changes in the newer buildings.
Sustainable Site Selection:
There should be easy availability of public transport and conveniences so as to cut down energy consumption for transportation. A suitably selected site thus gets the benefit of mass transit.
Also, rehabilitation of sites damaged by environmental contamination is a better option than any new piece of land where large amount of energy and resource is needed to make the land worthy of building on. Rehabilitation thus saves large amount of energy.
Already existing landscape, soil and natural features should be protected. For this reason, hard paving on the site should be avoided to preserve top soil and ease rain water harvesting. There should be minimum storm water runoff.
Material and Resources
· Sustainable construction material are chosen keeping in mind various characteristics like zero or low toxicity, high recyclability, zero or low off gassing of harmful air emissions, durability, reused and recycled content, sustainably harvested material.
· Dimensional planning and other material efficiency strategies are used to reduce the construction costs. Construction and demolition material can be reused and recycled for e.g. inert demolition material can be used as base course for landfills. Proper planning for managing materials through deconstruction, demolition and construction is done. Efficient planning of utilities to minimize
· Utilization of rapidly renewable materials, such as bamboo flooring, wool carpets, strawboard, cotton ball insulation (made from denim scrap), genuine linoleum flooring, or poplar oriented-strand board (OSB). Using rapid renewable helps reduce the use and depletion of finite raw material.
· Use of materials that are available locally is preferred over materials that need to be brought from distant places. It saves transportation costs. Also, alternative materials that can be generated from waste with lesser energy is used over conventional building materials.
For example, alternative materials for timber like MDF board, Mica Laminates and Veneers on composite boards should be used instead of natural timber. Industrial waste based bricks and blocks, aerated lightweight BPC concrete blocks, Phospho-Gypsum based blocks can be used for masonry structures. Fly ash, for bricks, outdoor paving and in concrete.
Installation of water efficient or low flow equipments in kitchens and bathrooms to reduce water consumption.
· Incorporating waste water management technologies like dual plumbing for using recycled water in toilet flushing or using water conserving fixtures such as low flow shower heads, self closing nozzles on hoses, water closets with dual flush options.
· Use of Micro irrigation techniques at sites instead of high pressure sprayers.
· Recirculation system for centralized hot water distribution.
· For landscaping purpose, local plants and trees are used as they consume less water.
· Provisions for reusing and recycling water are made to ensure efficient water management.
· Using treated waste water, non potable water for site irrigation. Raw sewage can be recycled using aquatic plants like duckweed and water hyacinth to produce clean water suitable for re-use in irrigation and industry.
· Integrating Rain water harvesting system in building design to ensure maximum possible utilization of rain water.