HERS Rating Northborough, MA — Stretch Code HERS 42/45
Certified HERS Rater serving Northborough, Massachusetts — helping builders, developers & homeowners meet the Massachusetts Stretch Energy Code and qualify for Mass Save incentives.
Get a Free QuoteCall 617-584-18092026 Massachusetts Energy Code Facts — Northborough
Northborough enforces the Massachusetts Stretch Energy Code (225 CMR 22), adopted effective 7/1/2017. Under the 2025 code update (current for 2026 permits), new homes in Northborough 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 7/1/2017) — 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 Northborough services: Blower Door Testing Northborough · Duct Leakage Testing Northborough · Stretch Code Compliance Northborough · 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 Northborough Energy Code
Do I need a HERS rating for a new home in Northborough?
Yes. Northborough has enforced the Massachusetts Stretch Energy Code since 7/1/2017, 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.
What HERS score is required in Northborough?
Homes permitted in Northborough 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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Northborough 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 Northborough 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 Northborough
Beyond the HERS maximums above, every new dwelling in Northborough 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 Northborough 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 Northborough.
Detail sourced from the 2025 Massachusetts Stretch & Specialized Codes Technical Guidance (DOER, Sept 2025), Table R406.5 and Appendix RC.
HERS Rating Services in Northborough, MA
HERS Rating Company provides certified HERS Index ratings in Northborough, Massachusetts. Our RESNET-accredited raters deliver fast, accurate energy ratings to keep your project on schedule and in full compliance with Massachusetts energy codes.
Whether building new or renovating in Northborough, MA, our certified HERS raters provide all documentation needed for building permits and final inspections.
Northborough is a historic Central Massachusetts town along the Assabet River, blending a classic New England town center with newer subdivisions and custom homes. Our RESNET-certified raters provide energy modeling, blower-door testing, and code compliance for builders and homeowners throughout the area.
All Services We Offer in Northborough, MA
Why Northborough Builders Choose Us
- RESNET Certified Raters — Fully accredited with years of Massachusetts experience
- Fast Turnaround — Energy reports delivered within 24 hours
- MA Stretch Code Experts — Deep knowledge of IECC 2021 & MA Stretch Code
- Mass Save Qualified — Help maximize your energy efficiency rebates
- Competitive Pricing — Transparent flat-rate quotes, no hidden fees
Massachusetts Stretch Energy Code in Northborough
The MA Stretch Energy Code requires all new residential construction to be verified by a certified HERS rater. Builders in Northborough must meet IECC 2021 requirements including air tightness tested by blower door and duct leakage verified by duct leakage testing. We provide all documentation required by the Northborough building department.
Ready to schedule your HERS rating in Northborough, MA? Get a fast, free quote today.
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Frequently Asked Questions — HERS Rating in Northborough, MA
How much does a HERS Rating cost in Northborough, MA?
HERS Rating costs in Northborough vary based on home size and project scope, but most single-family ratings fall within a competitive flat-rate range. Contact us at 617-584-1809 for a free quote tailored to your Northborough project.
Is a HERS Rating required for new construction in Northborough?
Yes. New homes in Northborough must demonstrate energy code compliance, and a HERS Rating is the most common path to verify performance and qualify for Mass Save incentives under the Massachusetts Stretch Energy Code.
How long does a HERS Rating take in Northborough?
Most Northborough projects receive their certified HERS report within 24 to 48 hours of the final inspection. We coordinate testing around your construction schedule to avoid delays.
What is the HERS score requirement for the MA Stretch Code?
The Massachusetts Stretch Energy Code generally requires a HERS Index score at or below the mid-50s for new construction, depending on home size and configuration. Our raters help your Northborough project hit its target score.