Ontario · Energy · checked September 28, 2026

Thermal imaging (thermographic) inspections in London

An infrared camera shows missing insulation, air leaks and damp spots without opening a wall, but only when it's at least 10°C colder outside than inside. London's long heating season gives you months of good scanning weather.

Get matched in London → How an infrared scan works
Hands holding an infrared camera aimed at a ceiling corner beside a frosty window; the screen shows a cold streak

Cost

Usually included; confirm

Best conditions

≥10°C inside/outside difference

Too little difference and leaks barely show

Winter design temperature

−18.4°C

The cold day heating is sized for

Houses built before 1961

25%

Older houses usually leak more and have less insulation

How London is built

London's houses by when they were built Ten house shapes, one for each tenth of London's 119,295 houses. Before 1961: 25%, 1961–1990: 41%, 1991–2000: 11%, 2001 or later: 24%. Older houses glow hotter.
  • Before 1961 25%
  • 1961–1990 41%
  • 1991–2000 11%
  • 2001 or later 24%
Each house stands for one in ten of London's 119,295 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. More snow in the drawing means more heating degree-days: a longer, colder heating season. Sources: Statistics Canada 2021 Census (table 98-10-0233-01), NRCan HOT2000 climate data.

When to book in London

London gets about 3,809 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 −18.4°C. Those figures come from the climate data for London in HOT2000, the home-energy software Natural Resources Canada (NRCan) gives energy advisors. That gives London a long window, roughly late fall to early spring, when the inside-outside difference comfortably exceeds the 10°C an infrared scan needs.

A 1950s brick bungalow on a snowy suburban street at dusk, lamplight in the front window
The same bungalow as an infrared camera sees it: heat glowing around the door, window frames, eaves and the rim joist above the foundation
Illustration: the same house in visible light and in infrared. A winter scan shows where heat escapes: door and window edges, the eaves, and the rim joist above the foundation.

What the camera finds in London houses

Of London's 119,295 houses (single-detached, semi-detached, row houses and duplexes), 25% were built before 1961 and 66% before 1991, according to the 2021 Census. Older houses are where the camera earns its keep: empty or settled wall cavities, gaps at the top of walls, and cold corners where framing bridges the insulation. Run it with the blower door test depressurizing the house and every leak shows up as a cold streak.

What it costs

Most EnerGuide advisors include an infrared scan with the evaluation, but it isn't required, so confirm when you book. 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.

Great Lakes–St. Lawrence Southern Ontario and southern Quebec

What this means in London’s climate

Cold winters and hot, humid summers: seal the attic, dry the basement, plan cooling.

Why it matters here: Shows missing insulation and air leaks as cold spots.

Best timing: December to February, early morning or on an overcast day, with at least 10°C between inside and outside.

What else homes in London need →

Sources for this climate guide · checked October 26, 2026

NRCan-licensed service organizations serving London

A service organization is a company that Natural Resources Canada (NRCan) licenses to deliver EnerGuide evaluations; its registered energy advisors do the home visit. Most EnerGuide advisors bring an infrared camera, but it isn't a required part of the evaluation, so confirm when you book. The scan is most useful with the blower door running.

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 and local help in London

Provincial · needs an evaluation Home Renovation Savings — Home Energy Assessment path Up to $10,000 per home ($5,000 if heated with Enbridge gas), including $600 back on your two assessments, for insulation, windows, air sealing and more — if the follow-up assessment is done by December 31, 2026 Open · deadline

Thermal imaging inspection in London: common questions

When is the best time for a thermal imaging inspection in London?

Late fall through early spring, when it is at least 10°C colder outside than inside. Cold, overcast days with no direct sun on the walls give the clearest images.

Can a thermal camera see through walls?

No. It reads surface temperatures. Missing insulation or an air leak shows up because it changes the temperature of the wall or ceiling surface.

Who does thermal imaging in London?

Most of the 25 NRCan-licensed organizations serving London bring an infrared camera to an EnerGuide evaluation; confirm when you book.

Is thermal imaging the same as a thermographic inspection?

Yes. Thermography, thermal imaging and infrared scanning all mean reading surface temperatures with an infrared camera.

Thermal imaging inspection near London

Thermal imaging inspection in Waterloo79 kmThermal imaging inspection in Kitchener81 kmThermal imaging inspection in Brantford82 kmThermal imaging inspection in Cambridge90 kmThermal imaging inspection in Chatham-Kent98 km All 70 cities →

Sources

Checked September 28, 2026. Census figures are for the municipality (Ontario); climate data is NRCan's HOT2000 station London (10 km away).

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