Ontario · 16 local services · checked September 28, 2026

Home energy audits and home testing in London

London gets about 3,809 heating degree-days a year, 25% of its houses were built before 1961, and 25 NRCan-licensed service organizations list its postal codes. Pick a service for the local details.

Energy audits in London → All 16 services
A Victorian red-brick semi-detached house with a front porch in autumn

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. Snowfall scales with heating degree-days. Sources: Statistics Canada 2021 Census (table 98-10-0233-01), NRCan HOT2000 climate data.

London at a glance

Climate

London gets about 3,809 heating degree-days a year and has a winter design temperature of −18.4°C, according to NRCan's HOT2000 climate data for London.

Housing

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. The typical house dates from 1971–1980.

Heating

In the London area, 73% of households heat mainly with a forced-air furnace; natural gas is the main heating energy for 61% of households and electricity for 24% (Statistics Canada, 2023).

Radon

Health Canada's 2012 survey found 1.8% of 109 homes tested in the Middlesex-London Health Unit health region above the guideline. The larger 2024 Cross-Canada survey reports 3.5% (1 in 29) of houses at or above the guideline for the London, ON (London CMA) metro area.

Local service guides for London

Energy audits and tests

An energy advisor’s kit on a front-hall bench: infrared camera, pressure gauge with tubing, tape measure, headlamp and a floor sketch

Home energy audit

25 licensed organizations
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

Blower door test

3,809 degree-days
Hands holding an infrared camera aimed at a ceiling corner beside a frosty window; the screen shows a cold streak

Thermal imaging inspection

3,809 degree-days
A kitchen table with a house floor plan, a laser measure, a tape measure and a laptop showing the plan

Heat loss calculation

Design temp −18.4°C
A duct-testing fan on a basement floor connected by flexible duct to a furnace, a pressure gauge hanging from a joist

Duct leakage testing

73% forced-air
A gloved hand inserting a combustion analyzer probe into a furnace flue pipe in a basement

Combustion safety test

61% heat with gas
A heat recovery ventilator on a basement wall with four insulated ducts running up between the joists

Ventilation and humidity assessment

24% built since 2001
Loose-fill insulation between attic joists, a yellow ruler showing its depth and frost on the roofing nails above

Attic insulation inspection

66% built before 1991
Utility bills and a phone showing a monthly energy-use chart on a kitchen table

Energy bill analysis

London Hydro

Home health tests

A small digital radon monitor on a bookshelf in a finished basement family room

Radon testing

3.5% at or above guideline (2024)
A carbon monoxide alarm on an upstairs hallway wall outside the bedrooms at night

Carbon monoxide testing

Required by law
A moisture meter pressed into water-stained basement drywall, an air-sampling pump on a tripod nearby

Mold and air quality testing

66% built before 1991
A gloved hand holding a sealed sample bag above vermiculite insulation between attic joists

Asbestos and vermiculite testing

66% built before 1991
A gloved hand swabbing layers of cracked old paint on a wooden window sill

Lead paint testing

25% built before 1961
Filling a water-sample bottle at a farmhouse kitchen tap with the aerator removed, snowy fields and a barn outside

Well water testing

Wells in some areas

For businesses and buildings

An auditor walking between rooftop heating and cooling units on a snowy commercial roof

Commercial energy audit

5 incentive programs

Who does energy evaluations in London

25 NRCan-licensed service organizations list London postal codes. See the list with phone numbers and coverage →

Ontario directory: verified advisor profiles for London, with prices where published.

City programs in London

BetterHomes London loan

City of London program (FCM Green Municipal Fund-supported) with a free retrofit coach: loans up to $40,000 at a 2.5% fixed rate, terms up to 20 years, repaid through property taxes, with up to 50% of approved costs paid up front. The project must cut energy use by at least 25% (typically a $20,000-$30,000 investment); at least 80% of costs must be energy efficiency. For detached, semi, townhomes, duplexes and triplexes used as a full-time primary residence. Participants usually pay for the initial energy assessment ($500-$700) before financing approval; EnerGuide assessment costs are eligible for financing. Site updated Sept 2026.

BetterHomes London income-qualified incentives

Grants that do not have to be repaid, deducted from the loan balance after renovations. Paid on a sliding scale by energy savings: $2,500 at 25%, $3,000 at 30%, $4,000 at 40%, $5,000 at 50%, $6,000 at 60%, $7,500 at 75%, up to $10,000 at 100%. Household income must be under $95,000 for one person or under $115,000 for two to five people. Rental properties are not eligible.

Rebates and financing for London homes

Provincial · needs an evaluation Home Renovation Savings — Home Energy Assessment path Up to $10,000 per home for insulation, windows and air sealing, plus $600 back on your assessments — if the follow-up assessment is done by December 31, 2026 Open · deadline Provincial Home Renovation Savings — direct rebates (no assessment) Heat pumps up to $7,500 ($12,000 ground-source), solar with battery up to $10,000, plus attic, thermostat and appliance rebates — no assessment needed Open Federal CMHC Eco Improvement premium refund 25% back on your CMHC mortgage insurance premium after $20,000 of energy renovations Open

Cities near London

Waterloo79 kmKitchener81 kmBrantford82 kmCambridge90 kmChatham-Kent98 kmGuelph102 km All 70 cities →

Sources

Checked September 28, 2026.

Planning upgrades in London?

Tell us where you are and what you’re planning. We’ll connect you with a registered service organization for your area — no spam, no shared lead lists.

Email us what you’re planning, your postal code and the type of building (a house, a duplex or triplex, or a larger multi-unit building) — we’ll reply with registered service organizations for your area and which rebates apply.

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