Blower door testing in Terrebonne

Terrebonne gets about 4,531 heating degree-days a year, a measure of how much heating its climate needs, and its winter design temperature, the cold day heating systems are sized for, is −26.1°C. Those figures come from the climate data for L'Assomption, the closest comparable location in that data set (21 km away) in HOT2000, the home-energy software Natural Resources Canada (NRCan) gives energy advisors. That's about 15% more heating demand than the middle of the 70 cities we cover. A long heating season: air sealing and insulation pay back well, and every leak costs money for months.

Terrebonne summers are hot and humid, so the air sealing and insulation that cut heating bills also keep the house cooler, and a heat pump can do the cooling more efficiently than an old air conditioner.

Of Terrebonne's 34,470 houses (single-detached, semi-detached, row houses and duplexes), 5% were built before 1961 and 50% 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 Montréal area, the main heating energy is natural gas for 5% and oil for about 2% 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 Terrebonne
• Radon. Sealing shifts the pressure balance between the house and the soil. Health Canada's 2012 survey found 3.9% of 76 homes tested in the Région de Lanaudière health region above the guideline. The larger 2024 Cross-Canada survey reports 17.4% (1 in 6) of houses at or above the guideline for Montréal Metro Area (Montréal CMA). Test before and after big air-sealing jobs. Radon testing in Terrebonne

A blower door test is part of every EnerGuide evaluation rather than a separate purchase. In Quebec, EnerGuide evaluations are booked through the provincial Rénoclimat program: the pre-retrofit evaluation costs $150 plus taxes, reimbursed when you receive financial assistance under the program, and the first post-retrofit evaluation is free.

• 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.