Ontario · Energy · checked September 28, 2026

Attic insulation inspections in London

The attic is usually the cheapest big energy fix in a house, and the inspection decides how to do it: how much insulation is there, where air leaks through the ceiling, and whether anything up there must not be disturbed.

Get matched in London → What an attic inspection checks
Loose-fill insulation between attic joists, a yellow ruler showing its depth and frost on the roofing nails above

Cost

Included in an evaluation

Houses built before 1991

66%

Heating degree-days

3,809

Common finding

R-10–20 vs R-50–60 target

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.

What inspections find in London attics

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. Attics in older houses commonly have a fraction of today's recommended insulation, and top-ups done over the years often buried air leaks instead of sealing them first.

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. That's right around the middle of the 70 cities we cover. The colder the climate, the faster added attic insulation pays for itself.

Vermiculite. Loose, pebbly, grey-brown or silver-gold insulation may contain asbestos. Health Canada's advice is not to disturb it; have it sampled before any attic work. Asbestos and vermiculite testing in London

The right order for the work

  • Seal the air leaks first: top plates, pot lights, plumbing stacks, the hatch.
  • Fix ventilation baffles so new insulation doesn't block soffit vents.
  • Then top up the insulation. Burying unsealed leaks under new insulation wastes much of the benefit.

What an attic inspection checks.

NRCan-licensed service organizations serving London

Every EnerGuide evaluation includes an attic inspection: insulation depth, air leaks and red flags such as vermiculite or knob-and-tube wiring.

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.

Insulation programs in London

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 Municipal 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. Municipal 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.

Attic insulation inspection in London: common questions

How much attic insulation should a London house have?

Advisors commonly target around R-50 to R-60 in attics. Your EnerGuide report gives the recommendation for your house.

Can I top up the insulation myself?

Only after the air leaks are sealed and you've confirmed there is no vermiculite. The inspection tells you both.

Will more insulation stop ice dams?

Insulation helps, but ice dams are mostly caused by warm air leaking into the attic. Air sealing is the bigger fix.

Attic insulation inspection near London

Attic insulation inspection in Waterloo79 kmAttic insulation inspection in Kitchener81 kmAttic insulation inspection in Brantford82 kmAttic insulation inspection in Cambridge90 kmAttic insulation 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).

Get matched with a registered advisor in London

Tell us your postal code and what you’re planning. We’ll connect you with one licensed service organization serving 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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