Blower Door Testing & Building Envelope Assessment
You can feel the draft. You cannot see where it comes from, and neither can the person quoting you for new windows.
A blower door test measures how much air your house actually leaks, and then we go and find where it is leaking. Not a guess, not a sales pitch for insulation — a measurement, a list of the specific places air is moving through your building, and an honest ranking of what is worth fixing first.
What a blower door test is
A calibrated fan is fitted into an exterior doorway and sealed in place. The fan changes the pressure inside the house relative to outside, so that every gap, crack and unsealed penetration in the building envelope starts pulling air in the same direction at the same time. Two things then happen.
First, the equipment measures the airflow needed to hold that pressure difference. That number is your house’s air leakage — a figure you can compare, and repeat after the work is done to prove it improved.
Second, and this is the part owners care about, the leaks become findable. With the whole envelope under pressure, air moving through a gap behind a baseboard or around a pot light can be located instead of theorized about. We work through the house and record where it is going.
Where the air usually goes
- The attic hatch — often the single worst opening in the house
- Top plates, partition walls and dropped ceilings connecting straight to the attic
- Recessed light fittings and bathroom fans
- Rim joists and the sill plate at the top of the foundation
- Plumbing, wiring and duct penetrations through the envelope
- Ductwork running through unconditioned attics, crawl spaces and garages
- Window and door seals, and the gaps around the frames rather than the units themselves
- Crawl-space hatches, cold-air returns and chases
- Fireplace and chimney surrounds
The pattern matters more than any single item. Ten small leaks in the ceiling plane will beat one drafty window every time, and they cost a fraction as much to fix.
Why this matters in the North Okanagan
Our climate works the envelope from both ends. Winter cold snaps drive heat out through every gap in the ceiling plane, and the same stack effect pulls cold air in low down — which is why your feet are cold while the thermostat says the house is warm. In summer the flow reverses and the house takes on heat, and during smoke season it takes on outside air you would rather it did not.
Air leakage is also a moisture story. Warm indoor air carries moisture into cold cavities and attics, condenses there, and creates conditions for mold and rot in places nobody looks until there is a stain. Sealing the envelope is as much a durability measure as an energy one.
What you get
- The measured air leakage result for your building.
- A located, photographed list of the leakage points we found, room by room.
- Observations on insulation coverage and ventilation where they are visible and relevant.
- Recommendations ranked by what will make the most difference for the least money — and a plain note where something is best left to a specialist.
- A written report with photographs, notations and recommendations, delivered online, and a walkthrough with the inspector before we leave.
Who it’s for
Owners with high heating bills and a house that has never been comfortable. Buyers of older Okanagan housing stock who want to know the running costs before they commit, usually alongside a full home inspection. Owners of new builds who would like the envelope verified rather than taken on trust. Anyone planning insulation, window or renovation work who wants to know where the money should go — a test before the work tells you what to do, and a test after it tells you whether it worked.
Why us
Vin McConnachie is a Qualified Domestic Energy Assessor with NHER in the UK, holds a Higher National Certificate with Commendation in Building Surveying from Greenwich University, London, and has spent 30+ years assessing how buildings perform on two continents. He also holds Consumer Protection BC Home Inspector Licence #78731 and is a Qualified Home Inspector with Carson Dunlop Canada. Energy assessment is not a sideline picked up last year — it is a qualification he trained for.
And we do not sell insulation, windows, spray foam or furnaces. There is nothing at the end of this test except the results.
Book the test
Call or text (250) 212-4025, or book online and tell us what the house is doing.
We look at your home with our heads so you can look at it with your heart.