Blower Door Testing Rehoboth MA - Quick Facts
Local energy code in Rehoboth
- Rehoboth is a Stretch Code community - the statewide baseline 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 Rehoboth is on the Stretch Code.
Blower door requirement in Rehoboth
- New homes in Rehoboth 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 Rehoboth building department.
Mass Save rebates for Rehoboth (2026)
- 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 Rehoboth MA
Certified blower door testing in Rehoboth - 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 Rehoboth MA
A blower door test is the code-required way to prove how airtight a home in Rehoboth 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 Rehoboth
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 Rehoboth Cold Spells
In winter the biggest enemy of a warm home is often invisible air movement. The stack effect drives heated air out through the top of the envelope and draws frigid air in near the floor, robbing heat all season - Cornell extension research describes it plainly as the effect that steals warmth from your home every winter.
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 Rehoboth Homes Leak Air
During depressurization the leaks are exaggerated, making them easy to find. In Bristol 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
- Drafty existing homes seeking targeted air sealing
- Mass Save incentive and rebate projects
- Custom and high-performance builds
- Homes chasing Passive House or net-zero targets
- Certificate-of-occupancy sign-off
Blower Door Testing Rehoboth MA Facts
Steadier indoor temperature
A tight home holds its heat longer between heating cycles, so rooms stay at a steadier temperature and recover faster after a cold, windy night.
Passive House airtightness
On the Specialized Code / Passive House path, whole-building airtightness follows Phius or PHI protocols - often around 0.6 ACH50, roughly ten times tighter than base code.
Warmer floors, fewer drafts
Cutting the cold air drawn in low means warmer floors and fewer cold-corner drafts, which is often the comfort difference people notice first after air sealing.
Older housing stock
Much of New England's housing predates modern air-sealing, so existing homes here often start well above 10 ACH50 - leaving large, cost-effective savings on the table.
Trusted for Blower Door Testing Rehoboth MA
Great job — thank you so much for your service. They helped me with the HERS ratings and guided me through the building process to help me reach passing scores! Thank you!
Very thorough, informative and prompt! Highly recommend!
One of the most reliable companies that I've worked with in Somerville, 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 Rehoboth MA
Does a tighter house need mechanical ventilation?
Yes. A tight home relies on balanced mechanical ventilation for fresh air, and the code sizes that ventilation (R403.6 / ASHRAE 62.2) using your verified blower-door rate.
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.
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 happens if my home fails the test?
The rater locates the leaks with smoke, an infrared camera, or by feel, those areas are sealed, and the home is retested until it meets the target.
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 does the 50 Pascal test pressure represent?
Fifty Pascals is roughly the pressure a 20 mph wind exerts on the whole building. Testing at a fixed pressure makes the result repeatable regardless of the weather that day.
Get Started With Blower Door Testing Rehoboth MA
Book a certified blower door test and get a permit-ready air-tightness report. Call 617-501-6788.
HERS Ratings in Rehoboth, Massachusetts
Home Energy Efficiency Consultants provides Rehoboth with certified HERS ratings, blower door and duct leakage testing, and Massachusetts energy-code compliance for new construction, additions, and major renovations — with same-day preliminary reports.
We rate homes across the Commonwealth from our four offices. Reach the one nearest your Rehoboth project — Somerville, Framingham, Marlborough, or Everett — or call (617) 501-6788 to schedule a Rehoboth rating.
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