Airtightness testing delivers energy and cost savings

Dogwood Suites is a 35,157 sq. ft. mixed-use building in Simcoe, Ont., with 51 affordable and market-rate rental apartments. The developer is Indwell, a Christian charity that has been supporting vulnerable adults dealing with mental health issues for nearly 50 years and one of the fastest-growing developers of new supportive affordable housing in Ontario.

By performing building envelope airtightness testing as part of the Enbridge Gas Commercial Airtightness Testing program, they were able to significantly reduce air leakage and annual heating loads.


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    Indwell participating in the Enbridge Gas Commercial Airtightness Testing program and benefited with lower operating costs over the lifetime of the building.

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    The program provided more sustainable and resilient building that has a lower carbon footprint and reduction in air leaks providing healthy indoor air and control of heating and cooling loads.

By the numbers

reduction in air infiltration

reduction in annual heating load

square feet


† Based on estimated savings identified by Evergreen Consulting Inc. Reductions are in comparison to the Toronto Green Standard target of 2.0 lps/m2 @ 75 Pa.

“As airtightness testing moves towards mandatory, the Enbridge Gas program is helping builders and developers know what to do and how to implement the process before it becomes code.”

Austin Todd, Principal Consultant,
Evergreen Building Science Inc.

Collaborating to achieve performance standards

Indwell worked with Evergreen Building Science Inc. and Schilthuis Construction Inc. to plan for and perform building airtightness testing as part of their quality control process.

“Airtightness testing, also known as a blower door test, is a procedure to measure the airtightness of a building envelope,” says Austin Todd, Principal Consultant, Evergreen Building Science Inc. “We use portable fans to create a controlled pressure difference from the inside to the outside of a building. That controlled pressure difference forces air through any gaps or cracks that may be there. The blower door fans quantify the air leakage rate. Then we use additional specialized equipment, such as fog machines and thermal imaging cameras, to locate the sources of air leakage. The total airflow rate is a very good predictor of building envelope performance and highlights vulnerabilities in the building envelope.”

Identifying and remediating air leaks

To minimize disruption, the Dogwood Suites testing was scheduled for a Friday afternoon when trade activity is typically low. The testing took 5.5 hours and diagnostics revealed numerous air leaks around door frames, window rough openings, kitchen range hoods, open conduits on the exterior and through the sump-pit, among other very common areas. After the sources of air leakage were identified, Schilthuis sealed the holes with specialized tape and membranes to further reduce the air leakage rate and ensure a healthier, more durable structure throughout the lifetime of the building.

“ As building owners and municipalities are now requesting high-performance buildings, we’re seeing more and more builders and developers step up and perform airtightness testing.”

Austin Todd, Principal Consultant,
Evergreen Building Science Inc.

More sustainable, durable buildings

“The main advantage of performing airtightness testing while the air barrier system is still exposed is the opportunity to make significant improvements without more costly, disruptive measures,” says Todd. “This is especially relevant if your building is trying to meet municipal or certification requirements.” As soon as the primary air barrier system is covered by either interior finishes or cladding, the opportunity to reduce the air leakage rate is greatly diminished.

“Participating in the Enbridge Gas program gives builders and developers the confidence and experience to bid on and deliver future high-performance projects,” says Todd. “It allows construction teams to develop their own best practices on implementing and airtightness testing quality control processes.”

New construction projects 25,000 square feet and over may qualify:

  • Commercial
  • Institutional
  • Multi-residential

Expert help and incentives to test commercial building airtightness

Even the best commercial building envelope design can fall short of optimal performance as a result of construction misses. Commercial airtightness testing provides an opportunity to identify and address issues before the building is occupied, to avoid much more difficult and costly corrections.

For commercial and multi-residential builders and developers, Enbridge Gas provides incentives up to $45,000* for testing and to resolve any issues discovered in the process, to help ensure intended performance standards are achieved. Airtightness testing should take place before the envelope is fully constructed to provide early identification of potential air leakage issues in order to qualify for incentives.

Incentives up to $45,000*

Commercial and multi-residential builders and developers can earn incentives that reward them for a high-performance building envelope.

Airtightness testing incentive
$0.50 per square foot
  • Up to 80 percent of the cost of testing, up to a maximum of $30,000 in incentives per project.
  • Incentives will be paid upon submission of the final airtightness testing report.
Implementation incentive
Up to 50 percent
  • For AeroBarrier, caulking, sealing and other envelope improvements.
  • Maximum of $15,000 in incentives per project.

Enbridge Gas also offers free technical and hands-on training to industry professionals as part of the Commercial Airtightness Testing program.

Learn more

Space is limited, book your airtightness testing today

* HST is not applicable and will not be added to incentive payments. To qualify for the program, buildings must be located in the Enbridge Gas service area. Commercial or multi-residential new construction projects to be built subject to Ontario Building Code; building types include Part 3, Part 10 or Part 11. Project enclosure must be in a state to perform airtightness testing starting in 2023. Terms and conditions apply.