MA Stretch Code 2021: New Construction Requirements for Massachusetts Builders
HERS Rating Company · MA Stretch Code Compliance Specialists
The Massachusetts Stretch Energy Code (MA Stretch Code 2021) applies to all new construction in the 250+ Massachusetts municipalities that have adopted it. Here’s what every builder needs to know.
What Is the MA Stretch Code 2021?
The MA Stretch Code 2021 is an above-code energy standard based on the 2021 IECC with Massachusetts amendments. It requires new residential construction to achieve a minimum HERS Rating of 42 or lower (for single-family homes), tested blower door air leakage, and duct leakage testing where applicable.
Key Requirements
- HERS Rating ≤ 42 for most single-family new construction
- Blower door testing — maximum 3 ACH50 air leakage
- Duct leakage testing — required when ducts are outside conditioned space
- Projected HERS Rating — submitted at permit application
- Final HERS Rating — submitted before certificate of occupancy
The MA Stretch Code Compliance Process
- Contact a RESNET-certified HERS rater early in design
- Rater reviews plans and runs energy modeling
- Projected HERS Rating submitted with permit application
- Construction occurs with rater on-site for inspections
- Blower door and duct leakage tests performed at rough-in and final
- Final HERS Rating report submitted for certificate of occupancy
Which Cities Require MA Stretch Code?
Over 250 Massachusetts municipalities have adopted the Stretch Code, including Boston, Cambridge, Newton, Worcester, Framingham, and hundreds more. View our full MA Stretch Code compliance services.
Get MA Stretch Code Compliance Help
We handle the full compliance process from plan review to final HERS certification. Free consultation: 617-584-1809.
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HERS Rating Company is a RESNET-certified, Mass Save-approved HERS Rater serving all 351 Massachusetts cities and towns.
Serving Boston, Worcester, Springfield, Cambridge, Newton, Brookline, and all 351 MA cities. Get a free quote →
MA Stretch Code 2021 Requirements for New Construction
The MA Stretch Code 2021 (based on IECC 2021) requires: a RESNET-certified HERS Rating, blower door test result of 3.0 ACH50 or less, duct leakage of less than 4% of total system airflow, R-49 attic insulation, R-21 wall insulation, and high-efficiency mechanical systems. HERS Rating Company manages full Stretch Code compliance for builders across Massachusetts.
Which Massachusetts Cities Require the Stretch Code?
Over 270 Massachusetts municipalities have adopted the Stretch Code, including Boston, Worcester, Springfield, Cambridge, Newton, Brookline, Somerville, and most other cities. HERS Rating Company serves all 351 MA cities regardless of code tier. Call 617-584-1809 to confirm your municipality’s requirements.