Something interesting is happening to America’s housing industry: it’s becoming more energy efficient. As home energy costs continue to rise, homeowners and buyers are looking at houses differently now, with an eye on what the actual costs of homeownership are. And one of the ways they’re doing this is via the HERS Index.

The Home Energy Rating System (HERS) Index was developed by RESNET (Residential Energy Services Network) and is the nationally recognized system for inspecting, testing and calculating a home’s energy performance. By checking a home’s HERS Index Score, buyers can get an idea about how energy efficient that home is and whether or not it’s a good investment. Homeowners, on the other hand, are able to better understand how efficiently their homes are operating and what steps they can take in order to improve performance. This can result in lower utility bills and increased home comfort, while at the same time protecting the environment.

The HERS Index is an easy and incredibly effective way to understand how energy efficient a home really is, which would account for its growing popularity. In fact, the HERS Index Score can be described as the housing industry’s answer to the miles-per-gallon sticker one looks at when considering a new car.

A HERS Index Score is generated by doing a home energy rating, conducted by a certified RESNET Home Energy Rater. A lower score results in a more energy efficient home.

The U.S. Department of Energy has determined that a typical resale home scores 130 on the HERS Index while a standard new home is awarded a rating of 100. According to RESNET, most existing homes fall between the 120-140 score range.

An example of how HERS Index scores work is as follows:

  • A HERS Index score of 50 indicates a home that is 50% more energy efficient than a standard new home.
  • A HERS Index score of 150 indicates a home that is 50% less energy efficient than a standard new home.

If you happen to be shopping for a new home, then you would want to steer away from the one with a HERS Index Score of 150. And if that home (scoring 150) happens to be your home, then that may explain why your energy costs are high and your home comfort level low.

This trend is growing across the nation. Already there have been over one million homes that have been issued a HERS Index Score.

But it’s not only homeowners and buyers that are using the HERS Index when it comes to buying and selling houses. Increasingly, builders are getting their new homes energy rated and using the HERS Index Scores as a marketing tool. Also, many jurisdictions across the United States have now officially incorporated the HERS Index Score into their building energy codes, and the HERS Index has been adopted as the energy measurement standard by government agencies including:

  • Department of Energy
  • Department of Housing and Urban Development
  • Environmental Protection Agency (ENERGY STAR)


The Residential Energy Services Network (RESNET) is the independent, national nonprofit organization that homeowners trust to improve home energy efficiency and realize substantial savings on their utility bills. RESNET’s industry-leading standards are recognized by the U.S. Department of Energy and the U.S. Environmental Protection Agency, among others.

Some jurisdictions that have already incorporated the RESNET HERS Index Score into their building energy codes include (click on the link to view the energy code):

• State of New Mexico

• City of Boulder, Colorado

• City of Santa Fe, New Mexico

• Brookhaven, New York

• Boston, Massachusetts

• Harvard, Massachusetts

• Truro, Massachusetts

Click here to view the complete list.