HERS Index

What does a HERS rating say about a house?

The HERS Index measures a home’s energy efficiency and there are a lot of reasons to have a home energy rating performed on your house.

It can tell you so much about the home you live in, like how efficiently it’s operating and where you can make modifications for greater savings . When you’re selling your home, a low HERS Index Score can command a higher resale price. And when you’re buying a home you can anticipate the costs of energy bills and efficiency upgrades.

How does the HERS Index work?

A certified Home Energy Rater assesses the energy efficiency of a home, assigning it a relative performance score. The lower the number, the more energy efficient the 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.

• A home with a HERS Index Score of 70 is 30% more energy efficient than a standard new home.
• A home with a HERS Index Score of 130 is 30% less energy efficient than a standard new home.

To calculate a home’s HERS Index Score, a certified RESNET HERS Rater performs an energy rating test on your home and compares the data to a ‘reference home’– a model home of the same size and shape as the actual home. This ensures your score is relative to the size, shape and type of house you live in.

Variables included in an energy rating

• All exterior walls (both above and below grade)
• Floors over unconditioned spaces (like garages or cellars)
• Ceilings and roofs
• Attics, foundations, and crawlspaces
• Windows and doors
• Vents and ductwork
• HVAC systems, water heating systems, and your thermostat

Public Access to the RESNET National Rating Registry

RESNET has created a National Registry that contains information on certified RESNET HERS Raters and Home Energy Ratings. If you would like to confirm if a HERS Rater’s certification is in good standing or check the HERS Index Score of a home, this is the site for you.

Certified RESNET HERS Raters

The public can now access the following information on certified HERS Raters:

• The name of the certified HERS Rater
• The rating company name
• Location of the rating company
• Name and contact information of the rating quality assurance provider that certified the Rater and is responsible for the quality assurance oversight
• Whether the Rater is active or has a suspended/revoked certification

HERS Index Score of a Home

The public can now access the following information on rated homes:

• Address of home rated
• Name of rating company that rated the homes
• Date that rating was completed
• HERS Index Score of home

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