Glossary · Energy, bills & ratings

HERS Index

Also called: HERS · HERS score · HERS rating · HERS Index Score · Home Energy Rating System · Energy Rating Index

A US home energy score where 100 equals a typical home built to 2006 standards and 0 is net zero; each point is about 1% of energy use.

What it means

A certified RESNET HERS rater inspects and tests the home, including blower door and duct leakage tests, and models it against a reference home of the same size and shape. A score of 70 means about 30% more efficient than that reference, and 130 about 30% less efficient. It's used mostly for new homes and code compliance.

Why it matters in an audit

HERS scores appear in new-home marketing and in ENERGY STAR and DOE new-home programs, so they let buyers compare efficiency.

Typical numbers

Reference values with their sources. Your auditor’s report gives the figure for your own house.

What	Value	Source
Scale (RESNET)	100 = typical home built to 2006 standards; 0 = produces as much energy as it uses; 1 point ≈ 1% change in energy use	resnet.us ↗
Average score of homes rated in 2025 (RESNET, Aug 6, 2026)	53, across more than 420,000 homes	resnet.us ↗

Sources

Learn more here

Related terms

RESNET HERS rater A professional certified through RESNET, the Residential Energy Services Network, to inspect, test and model homes and issue HERS Index scores.
Home Energy Score (DOE) A US Department of Energy 1-to-10 rating of an existing home's expected energy use, a bit like a miles-per-gallon rating for houses.
Net zero / net-zero ready home A net-zero home produces as much energy as it uses in a year, usually with solar; a net-zero ready home is built so it could, once panels go on.
ENERGY STAR The government-backed blue label for products and some homes that beat minimum efficiency standards by meeting stricter criteria.
Blower door test A test that uses a powerful, calibrated fan in an outside doorway to pull air out of the house and measure how leaky it is.

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