MA Stretch Code Compliance in Weymouth, MA
Complete MA Stretch Code 2021 (IECC 2021) compliance services for new residential construction in Weymouth, MA — from plan review through HERS certification.
2026 Massachusetts Energy Code Facts — Weymouth
Weymouth enforces the Massachusetts Stretch Energy Code (225 CMR 22), adopted effective 7/1/2016. Under the 2025 code update (current for 2026 permits), new homes in Weymouth 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.
- Energy code status: Stretch Code (effective 7/1/2016) — 1 of 242 MA municipalities (as of the June 2026 Mass.gov adoption list).
- Required testing & verification: blower door (air infiltration) testing, duct leakage testing, balanced mechanical ventilation (ERV/HRV), plus EV-ready and solar-ready provisions on the HERS compliance path.
- Mass Save® 2026 new-construction incentives: up to $25,000 per all-electric single-family home (Passive House tier; $7,500 base tier, $15,000 ENERGY STAR® NextGen tier — HERS ≤45), up to $40,000 for a 4-unit building, up to $3,750/unit for 5+ unit multifamily, and up to $30,000 for major all-electric renovations. Every tier requires enrollment and verification by an approved HERS rating company.
Related Weymouth services: HERS Rating Weymouth · Blower Door Testing Weymouth · Duct Leakage Testing Weymouth · 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.
Common Questions About the Weymouth Energy Code
Does Weymouth require a HERS rating in 2026?
Yes. Weymouth has enforced the Massachusetts Stretch Energy Code since 7/1/2016, 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.
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Homes permitted in Weymouth 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.
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Weymouth 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.
Official Maximum HERS Index Scores (Table R406.5)
These are the official maximum HERS Index scores that apply to projects in Weymouth 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.
Complete Stretch Code Compliance Requirements in Weymouth
Beyond the HERS maximums above, every new dwelling in Weymouth 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:
- Balanced mechanical ventilation (R403.6): an ERV or HRV system meeting minimum system airflow, heat/energy-recovery efficiency, fan sound ratings and regulated air-inlet and exhaust locations — verified by field testing.
- EV-Ready parking (R404.4): pre-wiring with a connection point and dedicated electrical panel capacity for future vehicle charging.
- Solar-Ready roof (Appendix RB): a dedicated solar zone with structural-load verification, an electrical interconnection pathway and reserved panel space — unless the project installs solar directly.
- Air-tightness & duct sealing: blower door result of 3.0 ACH50 or lower (Climate Zone 5) and duct leakage within 4 CFM25 per 100 sq ft.
Passive House alternative (R405): Phius or PHI certification satisfies the code in Weymouth 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 Weymouth.
Detail sourced from the 2025 Massachusetts Stretch & Specialized Codes Technical Guidance (DOER, Sept 2025), Table R406.5 and Appendix RC.
MA Stretch Code 2021 Compliance Services in Weymouth, Massachusetts
Complete MA Stretch Code 2021 compliance services for new construction in Weymouth, MA. We manage the entire process — plan review, energy modeling, blower door testing, duct leakage testing, and final HERS certification — so your project meets all requirements.
Weymouth has adopted the MA Stretch Code, requiring new residential buildings to achieve: HERS score 55 or below · blower door 3.0 ACH50 or less · total duct leakage 4% or less. All requirements must be verified by a RESNET-certified rater.
Our MA Stretch Code Compliance Process in Weymouth
- Plan Review & Quote: Submit your building plans. We review them, model them to a HERS score, and provide a compliance roadmap and quote.
- Pre-Construction Modeling: We model your plans to a HERS score before construction begins — identifying compliance risks cost-effectively.
- Construction Phase Testing: Intermediate blower door and duct tests verify compliance during construction.
- Final Certification: Final HERS Rating, RESNET-certified compliance report, and documentation for your building department.
Related Services in Weymouth
HERS Rating in Weymouth
HERS score 55 or below required for MA Stretch Code.
Learn More →Blower Door Testing in Weymouth
3.0 ACH50 or less required under MA Stretch Code.
Learn More →Duct Leakage Testing in Weymouth
4% or less total duct leakage required for forced-air systems.
Learn More →Frequently Asked Questions — MA Stretch Code Compliance in Weymouth
How much does MA Stretch Code compliance cost in Weymouth?
MA Stretch Code compliance package pricing in Weymouth: Single-family homes $1,850–$2,500 · Multifamily (per unit) $650–$1,200 · ADUs $1,600–$1,850. Full package includes HERS Rating, blower door testing, and duct leakage testing. Contact us for a free, project-specific quote.
Does Weymouth require the MA Stretch Code?
Yes. Weymouth has adopted the MA Stretch Code, requiring new residential construction to achieve: HERS score 55 or below · blower door 3.0 ACH50 or less · total duct leakage 4% or less — all verified by a RESNET-certified rater.
How do I prove MA Stretch Code compliance in Weymouth?
Compliance is documented through a RESNET-certified HERS Rating report. Our reports are accepted by the Weymouth building department and all Massachusetts municipalities as proof of MA Stretch Code compliance.
What is included in the full MA Stretch Code compliance package?
Our full compliance package for Weymouth includes: energy modeling from building plans · blower door air leakage test · duct leakage test · final HERS Rating · RESNET-certified compliance report for the building department.
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Get MA Stretch Code Compliance in Weymouth
Contact HERS Rating Company for a free quote on MA Stretch Code 2021 compliance in Weymouth, MA. Full package: HERS Rating, blower door, and duct leakage testing.