A home is given a numerical score, called the HERS Index Score, which indicates the home’s energy efficiency. The Residential Energy Services Network (RESNET) introduced the HERS Index many years ago.
A lower HERS Index score means a more energy efficient home. And the lower the HERS score, the lower your utility bills and the more comfortable the house will be. Like the miles per gallon tells how efficiently a CAR uses fuel, the HERS Index Score tells how efficiently a HOUSE uses fuel.