Energy efficiency in buildings and related assessment tools under Indian perspective

The Building sector stands only after the Industrial sector as far as energy utilization and related CO2 emission criterions are concerned. Electricity use in buildings is increasing by leaps and bounds due to growing urbanization, climate change-related factors and economic developments. An energy efficient building (EEB) or in a broader sense green building (GB), besides making positive impact on Environment and Public Health, also minimizes operating costs, maximizes productivity by the users and facilitates creation of sustainable community. The potential to reduce energy consumption through energy efficient design of new buildings and retrofits to existing buildings are quite high. The rating tools available in India are utilized to help the decision makers to quantify the energy and water efficiency and other parameters to finally establish the performance of the building with least environment damaging effects, without compromising the intended functional purpose. The Energy Conservation Building Code (ECBC) was introduced by Bureau of Energy Efficiency (BEE), Govt. of India, in 2007, and subsequently revised during 2017, as a step towards promoting energy efficiency in Commercial building sector. Another Code titled Eco-Niwas Samhita (ENS) had been launched by BEE during December 2018, aiming energy efficiency in Residential building sector. The ECBC and EWS both provide design norms for thermal performance requirement by building envelop; lighting system including Day-lighting; HVAC system efficiency; Electrical Distribution system including Renewable energy generation and Water heating and pumping system. Adoption of these stipulations helps in obtaining Green Rating for Integrated Habitat Assessment (GRIHA) by The Energy Resources Institute (TERI) and another rating by Indian Green Building Council. These ratings help in assessing sustainable parameters in Energy Efficient Buildings. In this paper, an attempt has been made to describe briefly about such rating tools with some examples under the Indian context to establish the advantages of energy efficiency and environmental sustainability in building sector