What Energy Code Applies to New Construction in Massachusetts in 2026?
In 2026, new residential construction in most Massachusetts cities and towns must comply with the MA Stretch Code 2021, which is based on the 2021 International Energy Conservation Code (IECC 2021). The Stretch Code is a more stringent optional energy code that most Massachusetts municipalities have adopted. It applies to one- and two-family homes and low-rise multifamily residential buildings.
Key Requirements of the MA Stretch Code 2021
Under the MA Stretch Code 2021, new residential construction must meet these key requirements: a HERS score of 55 or less (verified by a certified HERS Rater); air leakage of 3.0 ACH50 or less (verified by blower door test); duct leakage of 4 CFM25 per 100 sq ft or less (verified by duct leakage test, if ducted HVAC); and insulation levels meeting or exceeding IECC 2021 prescriptive values. All verification must be performed by a RESNET-certified HERS Rater.
Has My City Adopted the MA Stretch Code?
As of 2026, over 300 Massachusetts municipalities have adopted the MA Stretch Code. If you are building in any of the major metro areas (Greater Boston, Worcester, Springfield), it is almost certain your city requires Stretch Code compliance. Check with your local building department or contact us and we can confirm for your specific city.
What Is the MA Stretch Code Timeline for a Typical Project?
The MA Stretch Code compliance process runs alongside your construction schedule. Typical timeline: Plan review and energy modeling before permit (1–2 weeks); mid-construction inspection when framing, insulation, and rough mechanicals are complete (1 visit); final blower door and duct leakage test when construction is complete (1 visit). Total HERS Rater involvement is 2–4 weeks depending on your build schedule.
How Much Does MA Stretch Code Compliance Cost?
Full MA Stretch Code compliance services cost $1,850–$2,500 for a single-family home, $650–$1,200 per unit for multifamily, and $1,600–$1,850 for an ADU. This covers everything from plan review to final certification. Contact us for a project-specific quote.
Get Started with MA Stretch Code Compliance
HERS Rating Company is a RESNET-certified HERS Rater providing MA Stretch Code compliance services throughout Massachusetts. We work with builders, developers, and architects on projects of all sizes. Get a free quote today.
Related Services in Massachusetts
HERS Rating Company is a RESNET-certified, Mass Save-approved HERS Rater serving all 351 Massachusetts cities and towns.
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Massachusetts New Construction Energy Code 2026 Guide
All new residential construction in Massachusetts must comply with either the Base Energy Code (IECC 2021), MA Stretch Code 2021, or Specialized Stretch Code — depending on which your municipality has adopted. Over 270 Massachusetts cities and towns have adopted the Stretch Code. HERS Rating Company provides full compliance services for all code tiers.
What Testing is Required for MA New Construction Energy Code?
Required testing includes: blower door air leakage test (must pass 3.0 ACH50), duct leakage test (must be under 4%), and a HERS Rating by a RESNET-certified rater. HERS Rating Company handles all testing and reporting. Call 617-584-1809 for a free new construction consultation across all 351 MA cities.