- 6175841809
- hersratingcompany@gmail.com
- 12 Pond St Ashland, MA 01721 United States
- 573 Washington St Quincy, MA 02169 United States
RESNET-certified HERS Ratings for new construction, renovations, Mass Save programs, and MA Stretch Code compliance in Cohasset, MA.
Cohasset enforces the Massachusetts Stretch Energy Code (225 CMR 22), adopted effective 1/1/2016. Under the 2025 code update (current for 2026 permits), new homes in Cohasset must reach a maximum HERS Index of 42 (mixed-fuel) or 45 (all-electric) — up to 48 with qualifying credits — verified by a RESNET-certified HERS rater. ADUs must meet HERS 52–58, and major alterations, additions or change-of-use projects HERS 65–75, depending on fuel type and on-site solar.
Related Cohasset services: Blower Door Testing Cohasset · Duct Leakage Testing Cohasset · Stretch Code Compliance Cohasset · MA Energy Codes Guide — or get a free quote from our RESNET-certified team (617-584-1809).
Sources: 2025 DOER Massachusetts Stretch & Specialized Codes Technical Guidance (Sept 2025); Mass.gov Building Energy Code Adoption by Municipality (June 2026); Mass Save 2026 Residential New Construction program.
Yes. Cohasset has enforced the Massachusetts Stretch Energy Code since 1/1/2016, so new dwellings need a certified HERS rating from a RESNET-accredited rater — with blower door and duct leakage testing — before the certificate of occupancy.
Homes permitted in Cohasset today must score HERS 42 or lower (mixed-fuel) or HERS 45 or lower (all-electric), up to 48 with qualifying credits. ADUs fall in the HERS 52–58 range and major alterations/additions in the 65–75 range, depending on fuel type and on-site solar.
Cohasset is one of 242 of Massachusetts’ 351 municipalities enforcing the Stretch Energy Code (225 CMR 22) per the June 2026 Mass.gov adoption list; 60 towns have gone further to the Specialized Code and 49 remain on the Base Code.
These are the official maximum HERS Index scores that apply to projects in Cohasset under Table R406.5 of the current code (2025 DOER Technical Guidance):
| Building type | New construction (permits after 7/1/2024) | New construction w/ embodied-carbon credit (R406.5.2) | Accessory Dwelling Units | Major alterations, additions, change of use |
|---|---|---|---|---|
| Mixed-fuel building | 42 | 45 | 52 | 65 |
| Mixed-fuel + solar electric | 42 | 45 | 55 | 70 |
| All-electric building | 45 | 48 | 55 | 70 |
| All-electric + solar electric | 45 | 48 | 58 | 75 |
Scores are measured before counting on-site renewable generation (per R406.5). Historic buildings may opt out for alterations under R503.1.1. Embodied-carbon credits (+3 points) come from low-GWP concrete and insulation EPDs per Table R406.5.3/R406.5.4.
Beyond the HERS maximums above, every new dwelling in Cohasset on the HERS pathway must satisfy four code sections — R403.6 (Ventilation), R404.4 (EV Ready), R406 (HERS) and Appendix RB (Solar Ready) — per the 2025 DOER Technical Guidance:
Passive House alternative (R405): Phius or PHI certification satisfies the code in Cohasset in place of a HERS score — with a Certified Passive House Consultant for design and a Phius Certified Verifier/Rater during construction — and still requires EV-Ready and Solar-Ready compliance. Prescriptive path: allowed only for buildings without individually separate dwelling units, additions, and alterations — and a whole-building prescriptive project must implement 2 of the 3 additional-efficiency packages in R408 (enhanced envelope, higher-efficiency HVAC, or reduced water-heating energy). Additions of 1,000 sq ft or more (or exceeding 100% of the existing floor area) must meet both R502.3 prescriptive and the R406.5 HERS limits. Level III alterations (work area over 50% of the home and over 1,000 sq ft) also trigger HERS compliance; historic buildings are exempt under R501.6. Note that ENERGY STAR® is no longer a compliance path — HERS and Passive House are the two certification routes in Cohasset.
Detail sourced from the 2025 Massachusetts Stretch & Specialized Codes Technical Guidance (DOER, Sept 2025), Table R406.5 and Appendix RC.
RESNET-certified HERS Ratings for new construction, renovations, Mass Save programs, and MA Stretch Code compliance in Cohasset, MA. Our RESNET-certified raters serve Cohasset and all 351 Massachusetts cities and towns.
New homes in Cohasset must achieve a HERS score of 55 or below under the MA Stretch Code. HERS Rating Company manages the complete compliance process — from initial energy modeling through on-site testing and certified report delivery.
Required air tightness test — included with every HERS Rating.
Learn More →Required duct blaster test for forced-air HVAC systems.
Learn More →Full IECC 2021 Stretch Code compliance from plan review to certification.
Learn More →HERS Rating pricing in Cohasset depends on project type: Single-family homes $1,850–$2,500 · Multifamily (per unit) $650–$1,200 · ADUs $1,600–$1,850. Contact us for a free, no-obligation quote for your specific project.
Yes. Cohasset has adopted the MA Stretch Code, which requires all new residential construction to achieve a HERS score of 55 or below. A RESNET-certified HERS Rating is required to document compliance.
The on-site inspection in Cohasset typically takes 2–4 hours. We deliver your certified HERS report within 24 hours of the site visit.
New construction in MA Stretch Code municipalities like Cohasset must achieve a HERS score of 55 or below. The Specialized Stretch Code (adopted in some towns) requires HERS 45 or below for homes over 3,000 sq ft.
Contact HERS Rating Company for a free quote on HERS Rating services in Cohasset, MA. RESNET-certified, 24-hour turnaround.
We provide HERS Rating services throughout the region. Nearby cities we serve: Scituate · Norwell · Hanover · Hull
At HERS Rating Company, we are committed to providing the highest quality energy consulting services to homebuilders, architects, and developers across Massachusetts.
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