Blower Door Testing Greenfield MA - Quick Facts
Local energy code in Greenfield
- Greenfield enforces the Massachusetts Stretch Energy Code for new construction and major renovations. IECC Climate Zone 5A.
- Massachusetts has three energy-code levels - base (2021 IECC), Stretch, and Specialized (Opt-In) - and Greenfield is on the Stretch Code.
Blower door requirement in Greenfield
- New homes in Greenfield must test at 3.0 ACH50 or tighter under the Massachusetts Stretch Code.
- Air-leakage testing is mandatory, measured with a calibrated blower-door fan to the RESNET / ASTM protocol - there is no inspection-only substitute for the result.
- Companion duct leakage limit: 4 CFM25 per 100 sq ft of conditioned floor area when ducts run outside conditioned space.
- Same-day preliminary results; final report in 24-48 hours, filed with the Greenfield building department.
2026 Mass Save incentives in Greenfield
- A tight result unlocks Mass Save all-electric incentives ($7,500 to $25,000 per new single-family home); an all-electric renovation testing at 3.0 ACH50 or better reaches the Level 2 tier, up to $30,000.
- Incentives require a Mass Save-approved, RESNET-certified HERS rater.
RESNET-certified · 15,000+ ratings completed · 5.0 stars across 135 Google reviews · (617) 501-6788
Blower Door Testing Greenfield MA
Certified blower door testing in Greenfield - we measure your home's air-tightness in ACH50, pinpoint leaks, and document a passing result for your building permit.
Air-tightness at a glance
Blower Door Testing Greenfield MA
A blower door test is the code-required way to prove how airtight a home in Greenfield really is. A calibrated fan depressurizes the house to 50 Pascals so we can measure exactly how much air leaks through the envelope, reported as air changes per hour (ACH50). New construction must reach 3.0 ACH50 or lower, while remodels are allowed up to 5.0 ACH50.
| Project type | Max ACH50 | Notes |
|---|---|---|
| New construction | 3.0 or lower | Mandatory blower-door test under R402.4.1.2 |
| Remodel / alteration | 5.0 | Realistic target for existing assemblies |
| Addition < 1,000 sq ft | Exempt* | May be exempt from testing (R502.3.1) |
| Passive House / Specialized | 0.6 | Whole-building test, Phius/PHI protocol |
*Confirm with your local building department. Requirements per the 2025 MA Stretch Energy Code Technical Guidance.
How Blower Door Testing Works in Greenfield
The fan mounts in an exterior doorway and holds the home at a fixed 50-Pascal pressure difference - about what a 20 mph wind would exert. The airflow required to maintain that pressure, in CFM, converts to ACH50 using the home's conditioned volume.
The code converts the result to Q50 (CFM at 50 Pa) with Q50 = (Volume × ACH50) ÷ 60. A 2,700 sq ft home at 2 ACH50 works out to roughly 810 CFM50.
Keeping Heat In During Greenfield Cold Spells
During a New England cold snap the stack effect goes to work: warm indoor air rises and slips out near the top of the house, and that pulls cold outdoor air in through gaps down low. The colder it gets, the harder this effect pushes - so a leaky home loses the most heat exactly when it can least afford to.
Once the leaks are found and sealed, the home retains heat far longer between heating cycles. Floors stay warmer, temperatures hold steady on windy nights, and the reduced heating load shows up directly on winter utility bills.
Lower heating load
Less infiltration means a smaller winter heat-loss load and equipment that can keep up.
Retain paid-for heat
Warm air stays in the living space instead of escaping out the top of the house.
Steadier comfort
Fewer cold-floor drafts and a temperature that holds between heating cycles.
Where Greenfield Homes Leak Air
During depressurization the leaks are exaggerated, making them easy to find. In Franklin County's older housing stock the usual suspects are rim joists, top plates, attic hatches, recessed lights, and penetrations for plumbing and wiring. Coastal and exposed sites feel wind-driven infiltration most, so a tight, verified envelope pays back quickly here.
Best Fit for Projects Like
- Homes chasing Passive House or net-zero targets
- Certificate-of-occupancy sign-off
- Multi-family and townhouse units
- Additions over 1,000 sq ft that trigger testing
- New single-family homes needing a code compliance test
Blower Door Testing Greenfield MA Facts
Infiltration and heat load
Infiltration is frequently the single largest line item in a residential heat-loss calculation, so a tighter envelope directly shrinks the required heating capacity.
The Q50 conversion
The code converts the ACH50 result to Q50 (CFM at 50 Pa) using Q50 = (Volume x ACH50) / 60. A 2,700 sq ft home at 2 ACH50 works out to about 810 CFM50.
When the test happens
The blower door test is typically run near completion, once the air barrier, windows, and penetrations are sealed but while any needed corrections are still easy to make.
Smaller design heating load
Because infiltration is a major line in the winter heat-loss calculation, verifying tightness lets a designer lower the design heating load and right-size equipment.
Trusted for Blower Door Testing Greenfield MA
Had a pleasure working with Dom. Everything in the building turned out great and air tight for the coming winter.
Top notch service from start to finish.
Five stars isn't enough. The team at Home Energy Efficiency Consultants LLC goes above and beyond every time. They're the gold standard for HERS ratings in Massachusetts.
Our Massachusetts Service Locations
Serving clients from our Massachusetts locations in Everett, Somerville, and Framingham.
Everett Location
371 Main St
Everett, MA 02149
Somerville Location
519 Broadway
Somerville, MA 02145
Framingham Location
68 South St
Framingham, MA 01702
FAQ About Blower Door Testing Greenfield MA
Can a blower door test find where my home is drafty?
Yes. Depressurizing the home exaggerates the leaks so a rater can pinpoint exactly where outdoor air is entering, which guides targeted air sealing.
Where do most leaks occur?
Common culprits are rim joists, top plates, attic hatches, recessed lights, plumbing and wiring penetrations, and gaps around windows and doors.
What is the threshold for a remodel?
Remodels and alterations to existing homes are allowed up to 5.0 ACH50, a more realistic target given that older assemblies are harder to seal than new framing.
What documentation do I receive?
You receive the measured ACH50 result on a RESNET/HERS-style report suitable for the building department, plus notes on any sealing performed.
How long does a blower door test take?
For a typical single-family home the test itself usually takes well under an hour once the fan is set up and the home is prepared.
How tight is a Passive House?
Passive House projects on the Specialized Code path target around 0.6 ACH50 - roughly ten times tighter than base code - verified with a whole-building blower-door test.
Get Started With Blower Door Testing Greenfield MA
Book a certified blower door test and get a permit-ready air-tightness report. Call 617-501-6788.
HERS Ratings Across Greenfield and Nearby Communities
Home Energy Efficiency Consultants rates new homes, additions, and major renovations throughout Greenfield — including Downtown Greenfield, Greenfield Meadows, and Nash Mills. Every Greenfield project is filed with the Greenfield Building Department, and we handle the energy model, blower door and duct leakage testing, and the compliance paperwork from start to finish.
We also serve the communities right around Greenfield, including Deerfield, Montague, Gill, Bernardston, and Shelburne. Our Marlborough office at 272 Lincoln St is the closest of our four Massachusetts locations — see our Marlborough office or call (617) 501-6788 to get a Greenfield rating on the schedule.
More Massachusetts Towns We Serve
Certified HERS ratings, blower door testing and energy code compliance across all 351 Massachusetts cities and towns.
