Blower Door Testing Services in BC
A blower door test is the only way to know what your building's actual airtightness is. Under the BC Energy Step Code, every step from 3 onward requires a measured ACH50 result, and every project benefits from at least one mid-construction test before the drywall goes up. Okanagan AeroBarrier Inc. provides both pre-drywall diagnostic tests and final compliance tests for residential builders across British Columbia.
Our test results feed directly into the energy advisor's compliance file. We are a FortisBC Trade Ally member, owner Sebastian Motora has 13+ years of BC residential construction experience, and we have run blower doors on 100+ verified residential projects, including a build that finished at 0.24 ACH50. Read our deeper explainer on how blower door testing works if you want the long-form version.
What a Blower Door Test Measures
A blower door is a calibrated fan mounted in an exterior door opening. It depressurizes the building to 50 Pascals, and software calculates how much air the fan is moving to maintain that pressure. From that flow rate, the test reports two numbers builders care about:
- CFM50 - the cubic feet per minute of air the fan must move at 50 Pa to maintain the test pressure. This is the raw leakage rate.
- ACH50 - air changes per hour at 50 Pa. CFM50 normalized to the building's volume so two homes of different sizes can be compared on equal footing.
The BC Energy Step Code uses ACH50 as the compliance metric. Step 3 is 2.5 ACH50, Step 4 is 1.5 ACH50, and Step 5 is 1.0 ACH50. See our complete ACH targets reference for context on what each step means in practice.
Pre-Drywall Diagnostic Testing
The pre-drywall test, sometimes called the "rough-in test" or "mid-construction test," is the single most valuable test on a Step Code project. It happens after framing, insulation, windows, doors, and the air barrier are installed, but before drywall covers everything up.
At this stage every air barrier connection is still visible. We run the blower door, walk the building, and use a thermal camera, smoke pen, or hand to find leaks. Anything we find can be sealed in minutes by the framing crew. The same leak found after drywall could mean tearing into a wall or chasing the failure with caulking from an attic hatch.
Read more about the pre-drywall stage on our pre-drywall air sealing page.
Final Compliance Testing
The final test happens once the building is substantially complete. All exterior penetrations are finished, the HVAC is installed, and the building is in roughly the condition it will be lived in. The result from this test is what gets recorded on the energy advisor's compliance file and submitted to the local building department.
For most projects, the final test is the official Step Code compliance number. For projects targeting Step 4 or 5, the final test is also where the months of attention to detail pay off, or do not.
How to Prepare for a Blower Door Test
A few hours of prep on the builder's side makes the test go faster and produces a cleaner result.
Before We Arrive
- All exterior windows and doors closed and latched
- Interior doors open
- HVAC dampers, fresh air intakes, and dryer vents in their normal sealed-but-operable state
- Plumbing traps full of water (run every sink and tub for 10 seconds)
- Wood stove and fireplace dampers closed
- Combustion appliances off
- One exterior door free of obstructions for the fan
What We Bring
The blower door fan, frame, manometer, thermal camera, and any diagnostic gear needed to find leaks. The test itself takes 30 to 60 minutes for a typical single-family home, and we send the report the same day.
What Happens If You Fail
"Failing" a blower door test is not the end of the project, it just means the result is above the target ACH50 for your step. There are three common paths forward:
Find and Fix the Leaks
If the test happens pre-drywall, this is straightforward. The framing crew comes back, we run the blower door again while they work, and we watch the number drop. By the time we leave, you usually know exactly where you stand.
Use AeroBarrier
If you are out of options manually, or if the result is so close that one more day of caulking will not move the needle far enough, AeroBarrier can finish the job. We have used AeroBarrier as a "rescue" on builds that were 4 or 5 ACH50 above target and brought them well under in a single day.
Re-Test for Compliance
Once the fix is done, we re-test and issue a new report. The energy advisor uses the new number on the compliance file.
Where We Test
We run blower door tests across BC, with a focus on the Okanagan and Lower Mainland. Active service areas include Kelowna, Lake Country, Penticton, Kamloops, Burnaby, North Vancouver, Squamish, Nanaimo, and Langford.
Frequently Asked Questions
How long does a blower door test take?
A typical single-family home takes 30 to 60 minutes for the test itself, plus 15 to 30 minutes of setup and prep. If you also want a leak-hunting walkthrough with thermal imaging, plan on another hour.
When should I schedule the pre-drywall test?
After the air barrier, insulation, windows, and doors are installed but before any drywall, paint, or finishes go in. If the framing crew is still on site, even better, since they can address findings on the spot.
Do I need an energy advisor for the test?
For Step Code compliance, yes, the final result has to be recorded on the energy advisor's file. The energy advisor does not have to be present at the test, though, and many of our builders just send us the EA's contact info so we can deliver the report directly. See our energy advisor guide for how the relationship works.
Can you test commercial buildings?
Yes, for Part 9 commercial and multi-unit residential. Larger Part 3 buildings are handled through our commercial air sealing service.
What happens if I fail the final compliance test?
The building department will not issue an occupancy permit until the ACH50 number meets the target for your Step. We can usually rescue a failed test with same-day or next-day AeroBarrier work, depending on schedule and project size.
How do I book a test?
Call 250-864-8727 or email [email protected].