Blower Door Testing Everett MA - Quick Facts
Local energy code in Everett
- Everett 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 Everett is on the Stretch Code.
Blower door requirement in Everett
- New homes in Everett 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: 4.0 CFM25 per 100 sq ft of conditioned floor area total leakage (8.0 when all ducts are inside conditioned space - the test is still required).
- Same-day preliminary results; final report in 24-48 hours, filed with the Everett building department.
Mass Save rebates for Everett (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.
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Blower Door Testing Everett MA
Certified blower door testing in Everett - 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 Everett MA
A blower door test is the code-required way to prove how airtight a home in Everett 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, and no home on any compliance path may exceed 5.0 ACH50 (IECC 2021 R402.4.1.2).
| Project type | Max ACH50 | Notes |
|---|---|---|
| New construction | 3.0 or lower | Mandatory blower-door test under R402.4.1.2 |
| Maximum on any compliance path | 5.0 | Code cap under IECC 2021 R402.4.1.2 |
| Addition < 1,000 sq ft | Exempt* | May be exempt from testing (R502.3.1) |
| Passive House (PHI; Phius uses 0.06 CFM50/sq ft) | 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 Everett
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 Everett 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.
Sealing and verifying the envelope with a blower door test blunts that stack effect. You keep more of the heat you have already produced, cold-floor drafts fade, and the furnace or heat pump can actually hold temperature through the coldest stretches instead of running flat out and falling behind.
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 Everett Homes Leak Air
During depressurization the leaks are exaggerated, making them easy to find. In Middlesex 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
- Pre-drywall diagnostic testing for builders
- Homes chasing Passive House or net-zero targets
- Drafty existing homes seeking targeted air sealing
- Additions over 1,000 sq ft that trigger testing
- Certificate-of-occupancy sign-off
Blower Door Testing Everett MA Facts
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.
Ties into ventilation
Because a tight home needs mechanical fresh air, the verified blower-door rate feeds the R403.6 ventilation sizing under ASHRAE 62.2 - air sealing and ventilation are designed together.
Fail and reseal
If a result comes in above target, the leaks are located and sealed and the home is retested - the goal is a documented pass, not a single reading.
The ACH50 metric
Results are reported as ACH50 - air changes per hour at 50 Pascals. It tells you how many times per hour the home's entire volume of air would be replaced under that test pressure.
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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
Blower Door Testing in Everett: What to Expect
Everett has been on the Massachusetts Stretch Code since July 1, 2015, and it has not adopted the Specialized (Opt-In) Code. New homes in Everett, including new two- and three-family buildings, need a blower door test at final with a result of 3.0 ACH50 or lower before the certificate of occupancy. Passive House and Phius projects are held to much tighter limits.
Two-families, triple-deckers and leaks
Everett's housing is dense and old. Census estimates (ACS 2020-2024) show about 53% of units built before 1940 and just over half in two- to four-unit buildings, and the city's draft Housing Production Plan points to its many two- and three-family homes, duplexes and triple-deckers. When one of those buildings is gutted, older balloon framing can let air run from the basement to the attic inside the walls, so we look hard at rim joists, top plates, attic hatches, recessed lights, and plumbing and wiring chases. In multi-unit work, each unit can be tested on its own.
Inspections in Everett
The Division of Building Inspection is at City Hall, 484 Broadway, Room 26. Permits are filed through Everett's Online Permit Center on ViewPoint Cloud, and inspections are requested by calling 617-394-2220. The city lists typical inspection hours as Monday through Thursday, 10 a.m. to noon and 2 to 3:30 p.m. Book your blower door test before you call for the final.
Before the fan goes in
Close windows and exterior doors, open interior doors, turn off heating, cooling and ventilation, and fill drain traps with water. We seal exhaust and ventilation openings only as the protocol allows. If a unit tests above 3.0 ACH50, we keep the fan running while the leaks are found and sealed, then retest. Our own office is right in Everett at 371 Main St.
Real blower door tests by HEEC for Everett projects
These are photos from Home Energy Efficiency Consultants blower door testing jobs in Massachusetts — the same equipment and setup our certified raters bring to Everett homes.
FAQ About Blower Door Testing Everett MA
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.
Do you work with builders and homeowners?
We work with builders, remodelers, designers, and homeowners - from single tests for permit sign-off to pre-drywall diagnostics that catch problems early.
What is a blower door test?
It is a diagnostic that measures how airtight a building is. A calibrated fan mounted in a doorway pressurizes or depressurizes the home to 50 Pascals and measures the airflow needed to hold that pressure, which is reported as ACH50.
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.
When in construction should the test be done?
A pre-drywall diagnostic test is ideal for catching leaks while they are easy to reach, followed by a final compliance test near completion.
Why does my house feel drafty and cold in winter?
Much of that is the stack effect - warm air leaking out up high draws cold outdoor air in through gaps down low, chilling floors and lower rooms. A blower door test pinpoints exactly where that air is entering so it can be sealed.
How do I request an inspection in Everett?
Everett inspections are requested by calling Inspectional Services at 617-394-2220. The city lists typical inspection hours as Monday through Thursday, 10 a.m. to noon and 2 to 3:30 p.m., though times can vary.
Is Everett on the Specialized Code?
No. Everett has been on the Massachusetts Stretch Code since July 1, 2015, and has not adopted the Specialized (Opt-In) Code. New homes must pass a blower door test at 3.0 ACH50 or lower before the certificate of occupancy.
Blower Door Test Requirements for Everett Projects
Everett is not on the Specialized Code list. It has been on the Massachusetts Stretch Code (225 CMR 22.00) since July 1, 2015, according to the state's adoption list. The testing requirements below come from 225 CMR 22.00 and the 2021 IECC it amends.
| Requirement | Limit | Source |
|---|---|---|
| New home, prescriptive path | 3.0 ACH50 or lower | IECC 2021 R402.4.1.3 (Climate Zone 5, all of Massachusetts) |
| Maximum on any compliance path | 5.0 ACH50 or 0.28 CFM50 per sq ft of enclosure | IECC 2021 R402.4.1.2 |
| Attached homes and apartments tested unit by unit | 0.30 CFM50 per sq ft of unit enclosure (alternative) | IECC 2021 R402.4.1.2 exception |
| Mass Save ENERGY STAR tier | 1.5 ACH50 or lower | Mass Save new construction program |
| Passive House (PHI) | 0.6 ACH50 or lower | Passive House Institute |
| Passive House (Phius) | 0.06 CFM50 per sq ft of enclosure (0.08 for non-combustible 5+ stories) | Phius 2024 Certification Guidebook |
How the house is set up for the test
- Exterior windows and doors closed, with no sealing beyond normal weatherstripping
- Dampers closed but not taped, and interior doors open
- Exterior ventilation openings sealed, heating and cooling turned off, supply and return registers open
- Tested at 50 Pascals per ANSI/RESNET/ICC 380, ASTM E779 or ASTM E1827, with a signed report for the Everett building department
Sources: 225 CMR 22.00 (2025 edition) and the 2021 IECC sections listed. Everett is in Middlesex County, served from our Everett (371 Main St) office.
Blower Door Questions from Everett Builders
What blower door number does a new home in Everett need?
On the prescriptive path the 2021 IECC requires 3.0 ACH50 or lower in Massachusetts, and no home on any path may exceed 5.0 ACH50. Homes on the HERS path are tested the same way, and the result goes into the HERS model, so a tighter house earns a lower HERS score.
What is ACH50?
Air changes per hour at 50 Pascals: how many times the home's air volume leaks out each hour while a blower door holds the house at 50 Pa. ACH50 = CFM50 × 60 ÷ conditioned volume.
How are townhouses and apartments tested?
Each dwelling unit can be tested on its own and meet 0.30 CFM50 per square foot of the unit's enclosure, which counts walls, floor and ceiling shared with neighbors. Large buildings may also get a whole-building test.
What gets taped or closed during the test?
Windows and exterior doors are closed, dampers are closed but not sealed, and exterior ventilation openings such as bath fan and ERV/HRV terminations are sealed. Interior doors stay open and the heating and cooling system is off.
When should the blower door test happen?
The code test happens at the end of construction. We recommend a pre-drywall test once the air barrier is complete, when leaks are cheap to find and fix, so the final test is a formality.
How much does blower door testing cost in Everett?
Pricing depends on the size of the building and the number of units. Send your plans or address and we will quote the test, or bundle it with your HERS rating and duct test in one visit.
Related: Duct leakage testing in Everett · HERS rating in Everett · Stretch Code help in Everett
Get Started With Blower Door Testing Everett MA
Book a certified blower door test and get a permit-ready air-tightness report. Call 617-501-6788.
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HERS Ratings Across Everett and Nearby Communities
Home Energy Efficiency Consultants rates new homes, additions, and major renovations throughout Everett — including Everett Square, Glendale, West Everett, and Woodlawn. Every Everett project is filed with the City of Everett Inspectional Services 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 Everett, including Malden, Chelsea, Medford, Revere, and Somerville. Our Everett office at 371 Main St is the closest of our four Massachusetts locations — see our Everett office or call (617) 501-6788 to get a Everett rating on the schedule.
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