Buildings have major environmental impacts over their entire life cycle. Resources such as ground cover, forests, water, and energy are depleted to construct and operate buildings. Resource-intensive materials provide the building envelope and landscaping adds beauty to it – in turn using up water and pesticides to maintain it. Energy-consuming systems for lighting, space conditioning and water heating provide comfort to its occupants. Hi-tech controls add intelligence to ‘inanimate’ buildings so that they can respond to varying conditions, and intelligently monitor and control resource use, security, and usage of fire systems etc. in the building. Water is another vital resource for the occupants, which gets consumed continuously during building construction and operation. Several building processes and occupant functions generate large amounts of waste.
Thus, buildings are one of the major pollutants that affect urban air quality and contribute to climate change. Hence, the need to design a green building, the essence of which would be to address all these issues in an integrated and scientific manner. It is true that it costs a little more to design and construct a green building. However, it is also a proven fact that it costs less to operate a green building that has tremendous environmental benefits and provides a better place for the occupants to live and work in. Thus, the challenge of a green building is to achieve all its benefits at an affordable cost.
A green building depletes as little of the natural resources during its construction and operation. The aim of a green building design is to:
- Minimize the demand on non-renewable resources and maximize the utilization efficiency of these resources when in use, and
- Maximize reuse and recycling of available resources
- Utilization of renewable resources.
It maximizes the use of efficient building materials and construction practices; optimizes the use of on-site sources and sinks by bio-climatic architectural practices; uses minimum energy to power itself; uses efficient equipment to meet its lighting, air-conditioning, and other needs; maximizes the use of renewable sources of energy; uses efficient waste and water management practices; and provides comfortable and hygienic indoor working conditions. It is evolved through a design process that requires all concerned –the architect and landscape designer and the air conditioning, electrical, plumbing, and energy consultants – to work as a team to address all aspects of building and system planning, design, construction, and operation. They critically evaluate the impacts of each design decision on the environment and arrive at viable design solutions to minimize the negative impacts and enhance the positive impacts on the environment. In sum, the following aspects of the building design are looked into in 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 sources to generate energy onsite.
- Water and waste management
- Selection of ecologically sustainable materials (with high recycled content, rapidly renewable resources with low emission potential, etc.).
- Indoor environmental quality (maintains indoor thermal and visual comfort and air quality)