Yes. Massachusetts energy codes require a blower door test for virtually all new residential construction and many major renovations before a certificate of occupancy is issued. It is also a required part of every HERS rating.
New homes generally must achieve 3.0 air changes per hour at 50 pascals (3.0 ACH50) or better under the Massachusetts Stretch Energy Code. Tighter targets apply on Passive House and some specialized-code projects.
We locate the leakage points on-site - common culprits are attic penetrations, rim joists and duct chases - so your crew can air-seal and retest. Most homes pass after targeted air sealing. Call (617) 501-6788 for same-day scheduling.
Home Energy Efficiency Consultants provides blower door testing across Massachusetts for new construction, additions, renovations, HERS ratings, final verification, and energy code compliance. Blower door testing is one of the most important ways to confirm the building envelope is properly sealed for energy efficiency, comfort, and performance.
A blower door test measures how airtight a home is and helps locate leakage paths in the building envelope.
A blower door is a calibrated fan mounted into an exterior doorway. During testing, the fan changes the pressure inside the home so hidden leaks become easier to measure and identify. This allows the tester to evaluate how much uncontrolled air is moving through cracks, gaps, penetrations, framing connections, attic bypasses, basement transitions, rim joists, top plates, recessed lights, and other leakage points.
For Massachusetts homes, this matters because the building envelope needs to be sealed well enough to reduce wasted heating and cooling energy, improve comfort, support better indoor performance, and help projects meet code and program requirements. A blower door test gives a real measurement instead of a guess.
Blower door testing measures the home’s airtightness and gives a repeatable way to compare sealing quality from one project to another.
The test exaggerates leakage so problem areas in the envelope can be found and sealed before final turnover or failed inspections.
A tighter envelope helps reduce energy waste and supports insulation, HVAC performance, and overall building quality.
Blower door testing is important because the building envelope has to be sealed correctly for the insulation and mechanical systems to perform as intended. If the envelope leaks, conditioned air escapes and unconditioned air enters. That can increase heating and cooling loads, create drafts, reduce comfort, and make it harder for the home to perform efficiently.
Air sealing and insulation work together. Insulation slows heat flow, but uncontrolled air leakage can still move large amounts of energy through the envelope if gaps are left open. That is why air sealing is often one of the first and most cost-effective steps in improving efficiency.
Top plates, attic penetrations, recessed lighting, chases, and framing transitions are common sources of leakage that often need careful sealing.
Rim joists, sill plates, utility penetrations, and basement-to-first-floor transitions can be major leakage points if they are not sealed well.
Window rough openings, exterior doors, mechanical penetrations, plumbing penetrations, and electrical penetrations can all affect the final result.
A well-sealed envelope helps the home hold conditioned air where it belongs. That can reduce unnecessary heating and cooling demand, improve comfort, and make the home easier to control. It also helps insulation perform more effectively by reducing air movement through the enclosure.
In practical terms, a poorly sealed envelope can lead to cold drafts in winter, hot spots in summer, uneven temperatures, and extra strain on mechanical systems. A blower door test gives a direct way to see whether the envelope is actually tight enough to support good energy performance.
Use internal links from this main page to strengthen your core service pages.
Real feedback from homeowners, builders, and contractors who used our HERS rating and testing services.
A blower door test measures a home’s airtightness and helps locate leakage paths in the building envelope.
It verifies whether the envelope is sealed tightly enough to reduce wasted heating and cooling energy and support better overall home performance.
No. Insulation and air sealing work together. Even with insulation installed, uncontrolled air leakage can still reduce efficiency and comfort if the envelope is not sealed properly.
Yes. Blower door testing is commonly used as part of code compliance, HERS ratings, and project verification for new construction and other performance-based pathways.
This main page can support statewide relevance while your city pages target local searches.
Replace this example block with your full city list at the end of the page.
Paste your full city blower door testing page list here.
Example format:
Abington Blower Door Testing | Acton Blower Door Testing | Acushnet Blower Door Testing | Adams Blower Door Testing | Agawam Blower Door Testing
Call Home Energy Efficiency Consultants for blower door testing, HERS ratings, duct testing, and energy code guidance across Massachusetts.
Get StartedUnder the 2025 Massachusetts energy code amendments now in force, new homes must achieve 3.0 ACH50 or better on a blower door test — verified by a certified HERS rater before the certificate of occupancy is issued. The test depressurizes the home to 50 pascals and measures how many times per hour the full volume of air leaks through the envelope. Blower door results are also required for new-construction energy code compliance, large additions, and many Mass Save incentive tiers.
Every blower door test reports two numbers. CFM50 is how many cubic feet of air per minute the fan has to move to hold the house at 50 pascals of pressure. ACH50 is that same airflow turned into air changes per hour: CFM50 × 60 ÷ the volume of the house in cubic feet. Some programs use a third number, CFM50 per square foot of enclosure (walls, roof and floor area), because it treats small apartments fairly. Here is what each type of project has to hit in Massachusetts (Climate Zone 5) — 3.0 ACH50 for new homes on the prescriptive path, 5.0 ACH50 for remodels and other HERS-path projects:
| Project type | Air leakage limit | Where it comes from |
|---|---|---|
| New home, base code or Stretch Code | 3.0 ACH50 or less | 2021 IECC section R402.4.1.2 (Climate Zones 3-8), the basis of the Massachusetts energy code |
| ENERGY STAR single-family home | 3 ACH50 reference in Climate Zone 5 | ENERGY STAR National Program Requirements, Version 3.3 |
| ENERGY STAR multifamily unit | 0.30 CFM50 per sq ft of unit enclosure | ENERGY STAR Multifamily New Construction compartmentalization test |
| Phius passive house | 0.060 CFM50 per sq ft of gross enclosure (most projects) | Phius CORE standard |
| PHI (international) passive house | 0.6 ACH50 | Passive House Institute |
| Remodel, renovation or addition on the HERS path | 5.0 ACH50 or less, and the measured leakage goes into the HERS score (target HERS 65 mixed-fuel / 70 all-electric) | 2021 IECC cap of 5 ACH50 for performance and HERS (ERI) path projects; Massachusetts Stretch Code HERS targets |
Example: a 2,400 sq ft home with 9-foot ceilings holds about 21,600 cubic feet of air. To pass at 3.0 ACH50 it can leak no more than about 1,080 CFM50. Built to Phius with roughly 6,500 sq ft of enclosure, the same house could leak only about 390 CFM50 — around 1.1 ACH50, close to three times tighter.
Every cubic foot of air that leaks out has to be replaced by outside air that your heating or cooling system then has to heat or cool. In a Massachusetts winter that is cold, dry air pulled in through the basement and walls while warm air escapes through the attic. Sealing those paths cuts the load on the heat pump or furnace, evens out drafty rooms, keeps moist indoor air out of wall and attic framing, and lets a smaller system do the job. The EPA estimates homeowners save an average of 15% on heating and cooling costs (about 11% of total energy costs) by sealing air leaks and adding insulation. Because a tight house leaks so little, it needs planned fresh air from a bath fan, HRV or ERV — that is why ventilation is checked alongside the blower door test.
If a house fails, we walk it with the fan running and show your crew which of these spots are leaking so they can be sealed before the retest.
Photos from our own jobs: the calibrated fan and red panel are sealed into an exterior door, the house is depressurized to 50 pascals, and the gauge reads the airflow in CFM50 so we can calculate ACH50. The last photos are unit-by-unit tests in a new multifamily building.
A calibrated fan is mounted in an exterior door frame, interior doors are opened, windows and dampers are closed, and combustion appliances are set to pilot-safe mode. The test itself takes about an hour for most homes. You get the ACH50 result on the spot, and it feeds directly into your HERS rating.
Most failures trace to a handful of leak points: attic hatches, rim joists, recessed lighting, plumbing and wiring penetrations, and unsealed ductwork. We locate the leaks during the test, give your crew a prioritized fix list, and retest — usually the same visit or within days, so your certificate of occupancy is not held up.
Home Energy Efficiency Consultants is an ENERGY STAR® partner and U.S. DOE Efficient New Home partner (verified), rated 5.0 stars across 136 Google reviews, with offices in Somerville, Framingham, Marlborough, and Everett. Same-day and next-day appointments: (617) 501-6788.
A passing HERS rating can unlock more than a building permit. Mass Save residential new construction incentives remain available in 2026 for qualifying projects, and we handle the enrollment paperwork for eligible homes. Ask us which programs your project qualifies for. See our Mass Save rebate guide and Stretch Energy Code guide for details.
Sign up for our newsletter to receive exclusive updates, tips, and insights about energy-efficient building practices, financial incentives, and the latest energy code requirements in Massachusetts.
At Home Energy Efficiency Consultants, we are committed to providing the highest quality energy consulting services to homebuilders, architects, and developers across Massachusetts.
24/7 Support
MA 01702
Business Hr. 08:00-08:30
© 2026, All Rights Reserved.
The Phius Certified Verifier logo is used under license from Phius.
ENERGY STAR® Partner · U.S. DOE Efficient New Home Partner — Verified · Mass Save®-Listed HERS RaterSame-day HERS ratings & blower door testing across Massachusetts. We respond within hours.
Get My Free Quote →
