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Blower Door Testing

Building codes in Massachusetts require a blower door test on all residential new construction and many renovation projects.  A blower door test is a required component of a HERS Rating and many utility sponsored incentive programs including Mass Save.  This test is a valuable diagnostic tool to identify air leakage in the home.

A blower door test evaluates how “leaky” the house is and the test looks just like it sounds.  A frame and cloth panel are compression fit in an exterior door and a large calibrated fan is mounted in the frame. The fan depressurizes the interior of the house to a target pressure of 50 pascals and a computer measures how many cubic feet per minute (CFM) of air have to be removed from the house to hold that pressure.  The results can be expressed as CFM of leakage or more commonly as air changes per hour (ACH), how many times in one hour is the entire volume of the house exchanged.  Typically, energy codes require a maximum ACH allowed in residential construction; here in Massachusetts that maximum is 3.

Knowing the airtightness of buildings helps us forecast energy usage and calculate ventilation needs to ensure compliance with the codes in ASHRAE 62.1 and 62.2.  We also recommend using test smoke and/or an infrared thermal imager to locate the otherwise invisible drafts and infiltration points that can create problems in buildings.



If you are having trouble passing your blower door test, we recommend using the AeroBarrier aerosolized air-sealing system installed by New England Air Barrier.  This system allows precise control over the air tightness of the building envelope and guarantees results.

Installed just after plaster, this system allows you to pass the blower door test before installing interior trim.  Typical installations take 1-2 days and work can resume as soon as they are done since there is no off-gassing or chemical reactions. With the air sealing out of the equation, the entire spectrum of insulation products are on the table including all fiberglass batt installs. This allows us to help you find the best mix of products to fit your financial and performance goals.

We have partnered with New England Air Barrier to afford our clients a seamless way to pass the blower door test early in the project.  We know you are under pressure to deliver your house and New England Air Barrier has been delivering results to our clients, saving them time, money, and worry over the uncertainty of the blower door test.  To learn more, visit


If your project needs a blower door test, please call the office at 508-833-3100 or contact us online. We service Boston, Plymouth, Cape Cod and the surrounding areas in Massachusetts.