A blower door test answers a question most homeowners can only guess at: where is the air actually leaking? A calibrated fan is installed temporarily in an exterior doorway and used to change the pressure inside the building slightly. With the building under pressure, air moves through every gap and unsealed joint in the envelope — and leaks that are invisible in normal conditions become easy to find and evaluate.
If a room is always cold, a draft appears every winter, or heating costs seem out of proportion to the house, air leakage is one of the most common causes — and testing beats guessing before you spend money on sealing or repairs.
What blower door testing finds
Air rarely leaks where people assume. Testing routinely traces drafts and heat loss to exterior door and window perimeters, attic hatches, baseboards and wall transitions, plumbing and electrical penetrations, exhaust vent connections, recessed fixtures, and crawlspace or building-envelope junctions. During the test we work through the building locating leakage paths, using smoke testing where it helps make a leak visible, and record what we find.
Signs your home may benefit from testing
Drafty or cold rooms, uneven temperatures between floors, whistling around doors or windows, high heating or cooling costs, or a renovation that changed how the building behaves — any of these is a reasonable prompt. Testing is also useful when weatherstripping and seals are suspect but you’d rather confirm the real leakage paths than replace everything on principle.
How the test works
We start with a brief property assessment and preparation — interior doors open, mechanical systems set appropriately, fireplaces cold. The blower door is set up in an exterior doorway, the building is brought to a test pressure, and airtightness is evaluated. We then investigate room by room, tracing leakage to its sources, and finish with plain-language findings: where the building is leaking, which items are worth sealing, and which merit further investigation.
Homes, townhomes and buildings
Testing suits detached homes, townhomes and — where the suite configuration is practical — condominiums and small multi-family buildings. For stratas, air leakage testing pairs naturally with a ventilation inspection when residents report chronic drafts or comfort complaints, and findings feed directly into envelope maintenance planning.
Diagnostic, not certification
This is a diagnostic service: it finds and explains air leakage so you can act on it. It is not an energy audit, an EnerGuide evaluation or code-compliance testing, and we’re straightforward about that boundary — if your project needs certified compliance testing, we’ll say so rather than blur the line.