The HERS Index (Home Energy Rating System Index) is the industry standard for measuring a home's energy efficiency. A RESNET-accredited HERS Rater calculates the score after testing and inspecting a home — the lower the score, the more efficient the home.
How the Scale Works
0 = Net Zero Energy Home — produces as much energy as it uses
100 = Reference Home — a home built to 2006 IECC specifications, the baseline
150+ = well above standard energy use
A lower score means a more efficient home. A home that scores 70 uses roughly 30% less energy than the reference home; a home that scores 130 uses roughly 30% more.
How a HERS Rating Gets Calculated
The score comes from on-site testing and inspection, not just paperwork:
Blower door testing to measure whole-building air leakage
Duct blaster testing to measure HVAC duct leakage
Insulation inspections at the framing stage, before drywall
A review of the home's mechanical systems, windows, and envelope design
Why It Matters
Required for Texas's HB 3215 statewide compliance pathway in qualifying climate zones
Tied to ENERGY STAR certification and utility rebate programs like El Paso Electric's ENERGY STAR New Homes Program
Gives buyers a documented, third-party-verified efficiency number, not just a builder's claim
Curious what your project would score? Request an inspection or learn more about our services.