Air tightness testing of building during construction

This Blower Door Test is done to assess air leakage through the building envelope to ensure the build is on track to meet the building efficiency requirements. This is a non destructive, diagnostic test which depressurizes or pressurizes the home to identify unintentional leaks and issues with the air barrier.

It is designed to check for air leaks in walls, attics, and mechanical penetrations. While a blower door test does not evaluate how well a structure is insulated, it can reveal drafty walls and air-bypass situations that could undermine otherwise well insulated wall assemblies. A poorly sealed houses will have higher utility bills, issues with comfort, and potential mold and rot issues caused by moisture, potentially causing damage and deterioration of the building and leading to costly investigations and repairs..

This test is also a strategy to reduce construction deficiency claims and call backs after the building has been handed over.

In some Jurisditions all Part 9 buildings must complete a mid-construction blower door test prior to Insulation Inspection.
In those areas, applicants must submit a complete Mid-Construction Verification Report before a Building Official will conduct the Insulation Inspection. The applicants do not need to achieve a specific mid-construction airtightness performance, but the expectation is that the test results will be within the range of the required airtightness measurement to accieve the Step Code metric at the Final Assessment that willl be used to support the Occupation Premit application

The Mid-Contruction Blower Door Test Process

A mid construction blower door test is usually done at the pre-drywall phase of the building construction. While on-site the Energy Advisor can also do a Mid-Construction Verification checklist that is in some cases required before the Building Inspectors Insulation Inspection.

Once construction is complete, the builder can schedule a final Blower Door Test where the Energy Advisor will verify all the building components and also do the final blower door test that will be used to confirrm Step Code compliance. The Energy Advisor will complete an As-Built Compliance Report to be submitted with the Occupancy Permit Application.

In addition to the standard blower door test we also do an Infra red thermal scan with the blower door running. Thermal videography is used to locate and identify air leaks and poorly insulated area in the building. This is a powerful method that can help the advisor and builder to develop a stategy to improve building envelope tightness, proper ventilation, reduce energy usage and increase occupant comfort and health.

Benefits of a mid-construction blower door test include:

• A mid-construction blower door test helps to avoid surprises.
• It will also help the builder to confirm if they will meet energy efficiency targets early in the process.
• The cost of addressing air leakage issues during construction can be negligible. If you wait until construction has been completed to identify air leakage issues, fixing the problem may be time consuming, expensive, or nearly impossible and might even delay occupation as builders beed to pas the Step Code requirements before a Occupancy Permit is issues by the AHJ.
• The mid-construction blower door test can be a practical teaching tool for building crews and sub trades. If they are involved in the process, the test can be an opportunity for them to learn how to identify and address air leakage issues.
• Using the Thermal Imaging Camera during the mid-construction blower door test can be more educational than theoretical training on air tightness as the reults are visual and leaks can be corrected during the test.