Blower Door Testing in New Bedford, MA — Stretch Code HERS 42/45
RESNET and BPI-certified blower door air leakage testing for new construction, Mass Save programs, and MA Stretch Code compliance in New Bedford, MA.
2026 Massachusetts Energy Code Facts — New Bedford
New Bedford 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 New Bedford 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. New homes in Massachusetts (Climate Zone 5) must test at or below 3.0 ACH50 on the blower door test.
- 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 New Bedford services: HERS Rating New Bedford · Duct Leakage Testing New Bedford · Stretch Code Compliance New Bedford · 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 New Bedford Energy Code
Is a HERS rating required in New Bedford, MA?
Yes. New Bedford 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 New Bedford?
Homes permitted in New Bedford 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.
Which energy code does New Bedford follow in 2026?
New Bedford 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 New Bedford 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 New Bedford
Beyond the HERS maximums above, every new dwelling in New Bedford 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 New Bedford 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 New Bedford.
Detail sourced from the 2025 Massachusetts Stretch & Specialized Codes Technical Guidance (DOER, Sept 2025), Table R406.5 and Appendix RC.
Professional Blower Door Testing Services in New Bedford, Massachusetts
RESNET and BPI-certified blower door air leakage testing for new construction, Mass Save programs, and MA Stretch Code compliance in New Bedford, MA. Our RESNET-certified raters serve New Bedford and all 351 Massachusetts cities and towns.
New homes in New Bedford must pass a blower door test at 3.0 ACH50 or less 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.
Our Blower Door Testing Process in New Bedford
- Free Quote: Contact us for a transparent, no-surprise quote for your New Bedford project.
- Plans Review: For new construction, we review building plans and create an energy model before construction begins.
- Site Inspection: Our RESNET-certified rater visits your New Bedford property and performs all required testing.
- 24-Hour Report: You receive your certified report within 24 hours, ready for Mass Save, code inspectors, or green building programs.
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FAQs: Blower Door Testing in New Bedford, MA
How much does blower door testing cost in New Bedford, MA?
Blower door testing in New Bedford typically costs $200–$1,850. Contact us for a free quote.
Is blower door testing required in New Bedford?
Yes — New Bedford requires new residential construction to pass a blower door test at 3.0 ACH50 or less.
How long does a blower door test take in New Bedford?
A standard blower door test in New Bedford takes 1-2 hours. Certified report delivered within 24 hours.
What is ACH50 and what does New Bedford require?
ACH50 measures air changes per hour at 50 Pascals. New Bedford’s Stretch Code requires 3.0 ACH50 or less.
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