The number is the cheap part
A blower door test produces one number. That number tells you whether you passed. It doesn't tell you where the air went, which trade owns it, or whether it's still reachable.
By the time a final test reads 2.4 ACH50 instead of 1.5, the drywall is up and the leak is behind three trades' work. The test was accurate. It was just late.
The mid-construction leak hunt
We test once the air barrier is continuous and before insulation and drywall close it in. The shell holds pressure, and every penetration is still an arm's length away.
With the building held at 50 pascals we walk it with whoever is on site that day. The smoke pen shows the path at each detail. The thermal camera shows the cold. Your hand confirms it. Nobody leaves the site guessing which detail failed.
Where it is always leaking
Rim joist
Where the floor system meets the wall. The most reliable leak on a stick-built house, and the easiest thing in the building to seal before the insulator shows up.
Electrical penetrations
Every box, every wire pass-through, every pot light sitting in an insulated ceiling.
Bottom plate
The gap between plate and subfloor runs the entire perimeter, and nobody looks at it twice.
Rough openings
The shim gap around windows and doors, wherever the trade foamed it fast.
Top plates and partitions
Interior walls that stop short of the air barrier vent straight into the attic.
Mechanical penetrations
Every stack, dryer vent and HRV port that crosses the envelope.
And the attic hatch, which is usually the last thing built and the first thing forgotten.
What a failed final actually costs
A failed final test isn't a bad afternoon. It's a rework sequence.
The air barrier is behind drywall, paint and trim. Finding the leak means opening finished work. Fixing it means bringing back a trade that has moved on to another site. Proving it means a second test. On an ENERGY STAR or Net Zero project the label is gated behind the result, so the closing gets gated behind it too.
Measured against a lost week of schedule and a re-test, catching it at the air barrier stage isn't a line item worth arguing about.
Mid and final, booked together
The default engagement is two visits.
Mid-construction · diagnostic
- Run at air barrier completion
- Full walkthrough under pressure with your trades
- Punch list acted on before anything closes
- This is where the value is
Final · verification
- Run at substantial completion
- Documented ACH50 and CFM50 result
- The number you hand to the program or the client
- Confirms the fixes held
Booking both at once comes in under two separate call-outs, and you get a scheduled second visit instead of a re-quote three months later. Single tests are available when that's what the job needs.
What you get
- A punch list called out on site the same day, not emailed two weeks later
- ACH50 and CFM50 results — the metrics ENERGY STAR, Net Zero and Passive House programs score on
- Photo and thermal documentation of every leak located
- A written report you can hand to a client or a program reviewer
- Re-test verification after the fixes are made
Who tests, and what we don't do
Testing is run by Peter Kim, a Certified Passive House Tradesperson, using our own Retrotec blower door and digital manometer, a Retrotec smoke pen, and a FLIR thermal camera.
To be straight about scope: this is private quality-assurance testing for builders.
Issuing official EnerGuide or ENERGY STAR results requires a Registered Energy Advisor working under an NRCan service organization, and Passive House certification testing carries its own qualified-tester requirement. We aren't that, and we'll say so when your project needs one.
What we do is make sure that when the official test happens, it passes.
Have a shell going up?
Tell us where the project is and when the air barrier closes in. We'll tell you the right week to test.
Book a leak hunt →