What Is the Passing Threshold for a Blower Door Test in Massachusetts?
Under the MA Stretch Code 2021, new residential construction in Massachusetts must achieve 3.0 ACH50 or less on the blower door test. ACH50 stands for “air changes per hour at 50 Pascals of pressure” and measures how airtight your home is. A lower number means less air leakage and better energy efficiency.
What Causes a Blower Door Test Failure in Massachusetts?
Common causes of blower door test failures in Massachusetts new construction include: recessed light fixtures in insulated ceilings without airtight housings; electrical outlets and switch plates on exterior walls without air sealing; attic access hatches without proper weatherstripping and insulation; rim joists and band joists without continuous air barrier; penetrations for plumbing, wiring, and HVAC ducts without caulk or spray foam; window and door rough openings without proper sealing; dropped soffits and chases that connect conditioned and unconditioned spaces.
What Happens If My Home Fails the Blower Door Test?
If your home fails the blower door test (exceeds 3.0 ACH50), you will need to: identify the sources of air leakage, perform air sealing repairs, and schedule a re-test. Your HERS Rater can help you identify likely problem areas during the test. Re-tests are typically scheduled within 1–2 weeks of the original test. Most homes that fail on the first test are able to pass after targeted air sealing work.
How to Improve Your Blower Door Test Score
To improve your blower door test score in Massachusetts: use airtight recessed light fixtures; install electrical box gaskets on all exterior wall outlets and switches; apply spray foam at all penetrations through the top and bottom plates; use continuous rigid foam or housewrap as the air barrier at rim joists; install attic hatch covers with foam weatherstripping; and work with your HERS Rater during framing and rough-in to identify problem areas before drywall.
Book a Blower Door Test in Massachusetts
HERS Rating Company provides certified blower door testing throughout Massachusetts. We help builders identify and fix air leakage issues before the final test, improving your chances of passing on the first attempt. Contact us for a free quote.
Related Services in Massachusetts
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Blower Door Test Pass/Fail Standards in Massachusetts
Under the MA Stretch Code 2021, new homes must achieve 3.0 ACH50 or less to pass the blower door test. The Specialized Stretch Code requires 2.0 ACH50 or less. HERS Rating Company performs blower door testing across all 351 Massachusetts cities and works with builders to achieve first-time pass rates.
What to Do If You Fail the Blower Door Test in Massachusetts
If your home fails, HERS Rating Company provides a detailed report identifying air leakage locations. Common fixes: seal top plates, penetrations around pipes and wires, rim joists, window/door rough openings, and attic bypasses. After corrections, we retest to confirm compliance. Call 617-584-1809 to schedule your blower door test.