Home Energy Rating System (HERS)

A Home Energy Rating System (HERS) provides a standard measurement of a home’s energy efficiency. Ratings are used for both and new and existing homes. In new homes a rating is often used to verify energy performance for the EPA ENERGY STAR™ program, energy efficient mortgages, and energy code compliance. Homeowners who want to upgrade the home’s energy efficiency can use the energy rating to evaluate and pinpoint specific, cost-effective improvements as well as provide support documentation for energy improvement mortgages. For existing homes, homeowners can receive a report listing cost-effective options for improving the home’s energy rating. A Home Energy Rating allows a homebuyer to easily compare the energy performance of the homes being considered.

There are two types of Home Energy Ratings:

  • Projected ratings – Ratings performed prior to the construction of a home or prior to the installation of energy improvements to an existing home.
  • Confirmed ratings – Ratings completed using data gathered from an on-site inspection, which could include performance testing of the home.

Confirmed ratings involve an on-site inspection of a home by a residential energy efficiency professional, a Home Energy Rater. Home Energy Raters are trained and certified by a nationally recognized and accredited Home Energy Rater Training Provider. The Utah Energy Conservation Coalition is such an entity.

The Home Energy Rater reviews the home to identify its energy characteristics, such as insulation levels, window efficiency, wall-to-window ratios, the heating and cooling system efficiency, the solar orientation of the home, and the water heating system. Performance testing, such as a blower door test for air leakage and a duct blaster test for duct leakage, are usually part of the rating. The data gathered by the Home Energy Rater is entered into a nationally accepted and recognized computer program and then translated into rating score. The home receives a score between 1 and 100, depending on its relative efficiency. An estimate of the home’s energy costs is also provided in the report. The home’s Energy Rating may then be equated to a Star rating ranging from one star for a very inefficient home to five stars for a highly efficient home.

Unlike an energy audit or a weatherization assessment, a Home Energy Rating is a recognized tool in the residential mortgage industry. Home Energy Ratings can be used in a variety of ways in the housing industry. The star and the rating score provide an easily understandable means to compare more efficient homes by their relative energy efficiency, since a rating quantifies the energy performance of a home.