Ontario · Energy · checked September 28, 2026

Blower door testing in St. Catharines

A blower door test measures how leaky a house is and shows where the leaks are. In St. Catharines, with about 3,347 heating degree-days a year, every leak runs up the heating bill for most of the year.

A red blower-door panel with a large fan fitted into the front doorway of a brick bungalow, a pressure gauge on a stool inside

Cost

Included in an evaluation

Evaluation price

About $500–$700

Licensed organizations

24

Houses built before 1961

36%

How St. Catharines is built

St. Catharines's houses by when they were built Ten house shapes, one for each tenth of St. Catharines's 43,885 houses. Before 1961: 36%, 1961–1990: 47%, 1991–2000: 7%, 2001 or later: 10%. Older houses glow hotter.
  • Before 1961 36%
  • 1961–1990 47%
  • 1991–2000 7%
  • 2001 or later 10%
Each house stands for one in ten of St. Catharines's 43,885 houses (single-detached, semi-detached, row and duplex), drawn by when it was built. The glow shows the usual pattern: older houses tend to be leakier and less insulated. Snowfall scales with heating degree-days. Sources: Statistics Canada 2021 Census (table 98-10-0233-01), NRCan HOT2000 climate data.

Why air leakage matters in St. Catharines

St. Catharines gets about 3,347 heating degree-days a year and has a winter design temperature of −13°C, according to NRCan's HOT2000 climate data for Port Weller. That's about 15% less heating demand than the middle of the 70 cities we cover.

Of St. Catharines's 43,885 houses (single-detached, semi-detached, row houses and duplexes), 36% were built before 1961 and 83% 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.

After you seal: two checks

  • Combustion safety. In the St. Catharines-Niagara area, the main heating energy is natural gas for 70% 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 St. Catharines
  • Radon. Sealing shifts the pressure balance between the house and the soil. Health Canada's 2012 survey found 2% of 100 homes tested in the Niagara Regional Area Health Unit health region above the guideline. 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 St. Catharines

What it costs in St. Catharines

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.

How the test works

  • 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.

NRCan-licensed service organizations serving St. Catharines

A blower door test is part of every EnerGuide evaluation, so any organization below can do one in St. Catharines. Ask to walk the house with the advisor while the fan runs.

Only assessments from the seven HRSP-approved organizations qualify for the $600 Home Renovation Savings rebate and its assessment-path upgrade rebates; each listing below says whether it's one of them.

Source: NRCan list of licensed service organizations, checked September 28, 2026. Call to confirm your street is covered and ask about wait times.

Programs that include a blower door test in St. Catharines

Blower door test in St. Catharines: common questions

Where can I get a blower door test in St. Catharines?

Book an EnerGuide evaluation with any of the 24 NRCan-licensed organizations serving St. Catharines; the blower door test is part of every evaluation.

How much does a blower door test cost in St. Catharines?

It is included in an EnerGuide evaluation. 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.

What is a good blower door result?

Lower is better. Your EnerGuide report compares your air changes per hour at 50 Pa with homes of the same era, which is more useful than a single target number.

Does air sealing affect radon?

It can. Tightening a house changes the pressure difference with the soil, so test for radon before and after major air sealing.

Blower door test near St. Catharines

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