A HERS (Home Energy Rating System) is a measurement of a home’s energy efficiency. In the United States, the Residential Energy Services Network (RESNET) is responsible for creation and maintenance of the RESNET Mortgage Industry National Home Energy Rating Standards, as well as certification and quality assurance on RESNET Provider organizations.

Home energy ratings can be used for either existing homes or new homes. A home energy rating of an existing home allows a homeowner to receive a report listing options for upgrading a home’s energy efficiency. The homeowners may then use the report to determine the most effective ways in which to upgrade the home’s energy efficiency. A home energy rating of a new home allows buyers to compare the energy efficiency of homes they are considering buying.