Energy Performance Index
EPI or Energy Performance Index indicates the specific energy usage of a building. It is basically the ratio of total energy used to the total built-up area. This total energy used includes both purchased electricity as well as that generated on-site, but excludes renewable sources like solar photovoltaic etc. The total built-up area excludes basement and parking areas.
EPI is calculated after completion of one year of operation with full occupancy of the building and is measured in units of kWh/sq m/year.
For BEE Star rating, the bandwidths for Energy Performance Index for different climate zones have been developed based on percentage air-conditioned space. For example a building in a composite climatic zone like New Delhi and having air conditioned area greater than 50% of their built up area, the bandwidths of EPI range between 190-90 kWh/sq m/year. Thus a building would get a 5-Star rating if its EPI falls below 90kWh/sq m/year and 1 Star if it is between 165-190 90kWh/sq m/year.
Similarly the same building in a warm and humid climate zone like Chennai, the bandwidths of EPI range between 200-100 kWh/sq m/year and therefore it would get a 5-Star rating if its EPI is below 100 kWh/sq m/year and 1 Star if it is between 200-175 kWh/sq m/year.
Buildings having air conditioned area less than 50% of their built up area, in a composite climate zone the bandwidths of EPI range between 80-40 kWh/sq m/year. Similarly the same building in a warm and humid climatic zone like Chennai, the bandwidths of EPI range between 85-45 kWh/sq m/year, and in a hot and dry climate like Jodhpur, the bandwidths of EPI range between 75-35 kWh/sq m/year.