Quick Definition

The Home Energy Rating System (HERS) Index measures the energy efficiency of a home. A low HERS Index score means a home uses less energy, saving the homeowner money and reducing consumption.


In Depth

The HERS Index is a point-based rating system calculated by completing a home energy rating, which consists of:

  • Assessment of building components
  • Diagnostic/performance testing
  • Energy modeling

The HERS Index was developed by RESNET and is recognized by the Federal Government as a valid energy verification standard for all programs related to Federal residential tax credits, the EPA’s ENERGY STAR®  Certified Homes program and the Department of Energy’s Building America program.

The HERS Index score is calculated by a certified RESNET Home Energy Rater.

A home’s rating on the HERS Index is based on its energy performance. An energy efficient home has a low score on the HERS Index. According to the U.S. Department of Energy, a typical resale home scores 130 on the HERS Index; a conventional new home is awarded a rating of 100. A home scoring 70 on the HERS Index is 30% MORE energy efficient than a standard new home. A home scoring 0 would be considered a net-zero energy home.

Make It Right’s sustainable homes score in the 10-20 range on the HERS Index. [Insert gradient graphic here.]

Check out RESNET’s interactive tool to see how your home’s HERS Index translates annual savings, carbon footprint and comfort in your home.

Our Application

All of Make It Right’s projects are built to LEED Platinum certification standards; the HERS Index score of our homes and buildings is a significant component in meeting the LEED requirement.

We have developed several strategies to lower the HERS Index score of our homes:

  • Improving in the building envelope by switching from spray foam insulation to SIPs
  • Installing ENERGY STAR® rated windows
  • Installing ENERGY STAR® rated lighting & appliances
  • Increasing the amount of renewable energy by adding additional solar panels

Lessons Learned

By monitoring our HERS Index scores, we can gauge estimated projections of energy use versus the actual consumption. We work with local energy providers to monitor the energy production and consumption of our homes. This information, along with our HERS Index and LEED scores, helps us determine how a particular home’s design impacts its energy-efficiency and which designs are the most effective in reducing energy consumption and cost. (link to graphic)