Blower Door Testing in New Braintree, MA — ACH50 Requirements & What to Expect (2026)
The New Braintree air-leakage limit, how the blower door test works, what happens if you don’t pass, and how to book a certified test that satisfies your building department.
Blower Door Quick Facts — New Braintree
- New Braintree new homes must test at 3.0 ACH50 or lower (air changes per hour at 50 pascals).
- The blower door test is required to demonstrate energy-code compliance and to complete a HERS rating.
- It must be performed and documented by a certified rater using calibrated equipment.
- A failing result can be re-sealed and re-tested — we help pinpoint the leaks.
What the New Braintree Blower Door Test Measures
A blower door is a calibrated fan mounted in an exterior doorway that depressurizes the home to 50 pascals. The equipment measures how much air leaks through the building envelope, expressed as ACH50 — air changes per hour at 50 Pa. Tighter homes lose less conditioned air, cost less to heat and cool, and are more comfortable. In New Braintree, the Stretch Code caps new residential construction at 3.0 ACH50.
New Braintree Air-Leakage Requirement
| Building type | Maximum air leakage | Verification |
|---|---|---|
| New single-family home | ≤ 3.0 ACH50 | Blower door test at completion |
| Townhouse / attached dwelling | ≤ 3.0 ACH50 | Per-unit test |
| Addition (treated as dwelling) | ≤ 3.0 ACH50 | When conditioned space is added |
This limit is part of the Stretch Code that New Braintree enforces and is checked before your certificate of occupancy.
How the Test Works
1. Set Up
- Seal intentional openings
- Mount calibrated fan
- Close windows & doors
2. Depressurize
- Fan pulls to 50 Pa
- Measure airflow (CFM50)
- Convert to ACH50
3. Report
- Pass/fail vs 3.0
- Locate leaks if high
- Documented result
If Your New Braintree Home Doesn’t Pass
A high reading isn’t the end — it’s a punch list. Common leak points are rim joists, top plates, recessed lights, and penetrations. We identify the sources, you seal them, and we re-test. Getting the blower door done before insulation is covered makes fixes far cheaper.
Book Testing in New Braintree
We provide certified blower door testing across New Braintree and pair it with your HERS rating and duct leakage testing. For the full code picture, see New Braintree energy code help.
Quick Answers — New Braintree Blower Door Testing
Book a blower door test in New Braintree.
Talk to a certified Massachusetts HERS rater and get a free, no-obligation quote.
Call (617) 571-4368 Get a Free Quote