Blower door testing in Surrey

Surrey gets about 2,851 heating degree-days a year and has a winter design temperature of −6.3°C, according to NRCan's HOT2000 climate data for Pitt Meadows, the closest comparable location in that data set (13 km away). That's the 10th-lowest heating demand of the 70 cities we cover.

Of Surrey's 139,390 houses (single-detached, semi-detached, row houses and duplexes), 5% were built before 1961 and 39% before 1991, according to the 2021 Census. Older houses usually test leakier than newer ones, and an EnerGuide report compares your result with homes of the same era, so you can see whether your house is typical or a problem.

• Combustion safety. In the Vancouver area, the main heating energy is natural gas for 42% of households. A tighter house changes how fuel-burning appliances vent, so the spillage check should be repeated after serious air sealing. Combustion safety testing in Surrey
• Radon. Sealing shifts the pressure balance between the house and the soil. In Health Canada's 2012 survey, none of the 69 homes tested in the Fraser South Health Service Delivery Area health region were above the guideline, a small sample that doesn't rule radon out. The larger 2024 Cross-Canada survey reports 0.9% (1 in 113) of houses at or above the guideline for Vancouver Metro Area (Vancouver CMA). Test before and after big air-sealing jobs. Radon testing in Surrey

A blower door test is part of every EnerGuide evaluation rather than a separate purchase. There's no provincial price list; the City of Nanaimo quotes $400–$500 as typical for an existing home. Several B.C. municipalities subsidize evaluations for their residents (see local programs below).

• A calibrated fan is fitted into an exterior door and pulls air out until the house is at 50 pascals, the standard test pressure.
• The result is air changes per hour at 50 Pa (ACH50): how many times an hour the whole volume of air would leak out and be replaced at that pressure.
• While the fan runs, you and the advisor walk the house and feel for leaks at the attic hatch, rim joists, pot lights, trim and plumbing and wiring penetrations.
• A second test after the work shows what changed, and it is what most rebates pay on.

The blower door test in detail.