Blower door testing in Whitby

Whitby gets about 3,863 heating degree-days a year and has a winter design temperature of −19.8°C, according to NRCan's HOT2000 climate data for Toronto Buttonville, the closest comparable location in that data set (34 km away). That's right around the middle of the 70 cities we cover.

Of Whitby's 40,670 houses (single-detached, semi-detached, row houses and duplexes), 8% 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 Oshawa area, the main heating energy is natural gas for 72% 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 Whitby
• Radon. Sealing shifts the pressure balance between the house and the soil. In Health Canada's 2012 survey, none of the 95 homes tested in the Durham Regional Health Unit health region were above the guideline, a small sample that doesn't rule radon out. The larger 2024 Cross-Canada survey reports 12.4% (1 in 8) at or above the guideline for Ontario. Test before and after big air-sealing jobs. Radon testing in Whitby

A blower door test is part of every EnerGuide evaluation rather than a separate purchase. Typical Ontario prices are about $500–$700 for the initial EnerGuide evaluation and $200–$450 for the follow-up, plus HST where it applies. Windfall Ecology Centre charges $500 + HST for the initial evaluation and $250 + HST for the follow-up, Reep Green Solutions charges $540 and $406 with no HST, and City-backed programs in Ottawa and London quote $500–$700 as typical for the first visit. Only assessments from the seven HRSP-approved organizations qualify for the $600 Home Renovation Savings rebate, and none of the seven publishes a price.

• 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.