HERS: The Measure of Energy Efficiency


“Energy efficient” has described homes for years.  But how could you determine what “energy efficient” really meant, much less how much savings it could mean to you? Thanks to the Home Energy Rating System (HERS) Index, energy efficiency is now measurable. 

Much like calculating MPG in a car, HERS is a nationally recognized system that analyzes energy performance in new homes or homes that undergo complete renovations.  Lower scores mean higher efficiency and greater savings.

Scores are determined by independent raters who must be certified by the Residential Energy Services Network (RESNET), the organization which created the HERS system and trains raters to inspect and evaluate a home’s energy performance. 

Raters assign a value to a home and issue a certificate showing the HERS value and the expected annual energy consumption and annual energy cost as well as an estimate of annual cost savings over existing homes.

Scores indicate the efficiency of a particular home compared to other homes. The U.S. Department of Energy has determined that a typical existing (resale) home scores 130 on the HERS index and a standard new home scores 100. 

Soon after it launched in 2006, Ann Arbor Builders recognized that HERS provided a means for consumers to project monthly energy costs and to save on them. 

That's why every home we build is HERS rated.  And by using the energy efficient features we include in every home, regardless of size, our homes regularly score in the 60's. 

This means that our homes are over 60% more efficient than existing homes and over 30% more efficient than standard new homes.  And it translates to significant energy cost savings for our homeowners.  

By adding solar to the standard energy efficient features we regularly include, a recently built home of approximately 2000 square feet resulted in a HERS score of 44 and estimated savings of $3,041 during the first year for the homeowners.

Builders aren’t required to have homes they build HERS rated.  In fact, only about 20% of all new homes built in the U.S. in 2021 were. But we believe that it provides buyers a means of making informed choices when shopping for homes.  

And we believe that helping buyers save energy is the right thing to do.  Not only do they save on monthly energy costs, but HERS rated homes also help to reduce energy consumption.  The EPA calculates that the homes that were HERS rated in 2021 will reduce carbon dioxide emissions by over 1.236 million tons annually, the equivalent of taking 269,013 passenger vehicles off the road for one year. 

- Betsy de Parry, VP Sales and Marketing