What is a HERS Rater

HERS (Home Energy Rating System) Raters are special inspectors trained to evaluate construction techniques, take key measurements and perform inspections and diagnostic testing to verify a home’s energy performance. Based on a home’s plans the Rater uses an energy efficiency software program to perform an energy analysis of the home’s design. The Rater will work with the builder to identify the energy efficient improvements and ensure the house will meet ENERGY STAR performance guidelines. Then the Rater conducts onsite inspections and diagnostics (Blower door and duct leakage testing). The results of these tests will be input into the software to generate a final HERS Index score for the home.

The HERS Index is a scoring system established by the Residential Energy Services Network (RESNET) in which a home built to the specifications of the HERS Reference Home (based on the 2006 International Energy Conservation Code (IECC) scores an Index of 100, while a net zero home scores a HERS Index of 0. The lower a home’s HERS Index, the more energy efficient it is in comparison to the HERS Reference Home. Each 1-point decrease in the HERS Index corresponds to a 1% reduction in energy consumption compared to the HERS Reference Home. Thus a home with a HERS Index of 85 is 15% more energy efficient than the HERS Reference Home and a home with a HERS Index of 80 is 20% more energy efficient.

Some states have their own energy codes, such as Title 24 in California that require verification of some measures by HERS raters in order to finalize the completion of the home. The new Title 24 code version takes effect August 1, 2009. There are many new features and measures that involve HERS verification. Electronic filing will be mandatory.

The California Energy Commission established regulations to certify home energy rating services through a Home Energy Rating System (HERS). HERS ratings provide reliable information to differentiate the energy efficiency levels among California homes. Ratings also provide a guide to investing in cost-effective home energy efficiency measures. There are currently three certified HERS providers in California: California Home Energy Efficiency Rating System (CHEERS), California Certified Energy Rating and Testing Services (CalCERTS), and the California Building Performance Contractors Association (CBPCA).

CHEERS (California Home Energy Efficiency Rating System, Inc.) is a California statewide non-profit organization dedicated to promoting energy efficiency. CHEERS was created to provide a simple, accurate and reliable method of measuring the existing energy efficiency of a home, estimate the annual costs of the existing home and provide a list of energy saving recommendations for improvements.

The New Solar Homes Partnership (NSHP) requires a third party inspector called a Home Energy Rating System (HERS) Rater to provide field verification for certain energy efficiency measures and the PV system in a NSHP home.