Blower Door Testing - More than a Verification Tool

The 2018 International Energy Conservation Code (IECC) requires that new homes pass a building airtightness test, commonly known as a blower door test. The standard in Montana under the newly enacted 2018 IECC is four air changes per hour or less when tested at 50 Pascals. This is noted as 4 ACH50. Often, this is the only time a builder will ever utilize a blower door. The mantra among the building industry is “build it tight and ventilate right.” Using a blower door throughout the building process will let the builder know whether he is on the right track to “building it tight,” alleviating guesswork and the stress of a failed blower door test at the end of the construction process.