HERS Rating in Mount Washington, MA — Requirements, Index Targets & RESNET Process (2026)
What a HERS rating is, when Mount Washington projects need one, the Index score you must hit, and exactly how the rating is performed — from a certified RESNET HERS rater.
A Home Energy Rating System (HERS) rating measures a home’s energy efficiency on a scale where a standard new home scores 100 and a net-zero home scores 0 — lower is better. Mount Washington, MA uses a certified HERS rating to verify energy-code compliance for new construction and major renovations, and to qualify for Mass Save® incentives under the Massachusetts base energy code.
Required HERS scores in Mount Washington: new mixed-fuel (gas) homes must reach HERS 42 or lower; new all-electric homes HERS 45 or lower; additions & major renovations 65 (mixed-fuel) / 70 (all-electric); ADUs 52 / 55.
HERS Rating Quick Facts — Mount Washington
- A HERS Index scores a home’s energy performance: lower is better, 0 = net-zero, 100 = a 2006-code reference home.
- In Mount Washington a third-party HERS rating is recommended (and required for Mass Save incentives, ENERGY STAR, and most financing).
- The rating is performed by a certified RESNET HERS rater — not the builder or code official.
- It involves energy modeling, at least one rough inspection, and final diagnostic testing (blower door + duct leakage).
What Is a HERS Rating?
The Home Energy Rating System (HERS) Index is the national standard, administered by RESNET, for measuring a home’s energy efficiency. A certified rater builds an energy model of the home, verifies insulation and air-sealing during construction, and performs diagnostic tests at completion. The result is a single number — the HERS Index — that Mount Washington building officials, lenders, and incentive programs use to confirm performance.
HERS Index Targets for Mount Washington
Mount Washington is on the base Massachusetts energy code, so there is no mandatory HERS ceiling — but a strong HERS score is still needed to qualify for Mass Save rebates, ENERGY STAR, and energy-efficient mortgages.
| Project type | HERS Index target | Notes |
|---|---|---|
| New single-family home | No code HERS cap (base code) | HERS 50–60 typical for incentives |
The RESNET Rating Process, Step by Step
Every Mount Washington HERS rating we perform follows the same RESNET-accredited workflow:
1. Design & Modeling
- Review plans & specs
- Build the energy model
- Confirm the design hits target
2. Rough Inspection
- Insulation & air-barrier check
- Before drywall
- Photo documentation
3. Final & Testing
- Blower door test
- Duct leakage test
- Registered HERS certificate
Sampling & When a Rating Is Required in Mount Washington
A HERS rating is triggered for new residential construction whenever a builder pursues incentives or financing that require it. For multi-unit and production projects, RESNET sampling protocols can allow one rated home to represent a set — we’ll advise whether your Mount Washington project qualifies.
Documentation You Receive
At completion we register the rating with RESNET and provide the signed HERS certificate, the rating report, and the diagnostic test results your Mount Washington building department and incentive programs require. Need the tests on their own? See our Mount Washington blower door testing and duct leakage testing, or the full Mount Washington energy code overview.
Quick Answers — Mount Washington HERS Rating
Need a HERS rating in Mount Washington?
Talk to a certified Massachusetts HERS rater and get a free, no-obligation quote.
Call (617) 571-4368 Get a Free Quote