Home Energy Rating System

HERSThe Home Energy Rating System (HERS) is an evaluation of energy efficiency and forecasted energy costs within a home.

It produces a projected, pre-constructed HERS Index, a scoring system established by the Residential Energy Services Network (RESNET). Based on the 2006 International Energy Conservation Code, the HERS Reference Home is a standard new home that meets all energy requirements and has a HERS Index of 100.  A net-zero energy project will achieve a zero (0) HERS Index rating.  The lower a home’s HERS Index, the more energy-efficient it is in comparison to the HERS Reference Home.  Each point decrease on the HERS Index indicates a 1% reduction in energy use.

Certification Synergies

The LEED for Homes rating system utilizes HERS to configure its home energy prerequisites and credits.


Pittsburgh’s first net-zero home, Riverside Mews on the South Side,  achieved a HERS rating of -4, meaning it generates more energy than it uses!

RESNET also has a designation for professionals called certified HERS Raters, who inspect and test a home and prepare a comprehensive HERS rating.  Visit GBA’s Professional Credentials page for more information.

To find out more about this certification, visit the RESNET website, which includes:

  • More details about how a HERS rating works
  • Energy rating FAQs and benefits
  • Details about Certified HERS Raters (how to find one and become one)
  • News and articles