Quick answer: Our analysis of the 2026 Home Renovation Savings attic rules shows the rebate covers exactly 50% of your job until you hit the cap, then its share drops. For the lowest-insulated attics (R-12 or less), the $1,250 cap is reached at an after-tax price of $2,500. Above that, every extra dollar is yours. Homes starting at R-12 or less get the most back and also see the biggest cut in heat flow through the attic, about 76% when upgraded to R-50.
Updated November 2026
On this page
- Key findings
- Method
- Finding 1: where the rebate stops covering half
- Finding 2: rebate share at different job prices
- Finding 3: net cost after the rebate
- Finding 4: how much heat flow each upgrade cuts
- Finding 5: older homes leak more, and it costs more
- How to use this study
- Citation
- Frequently asked questions
- Get your rebate estimate
Key findings
- The “50% line” ends at twice the cap. Full rebate is reached at $2,500 (R-12 tier), $2,000 (R-12 to R-25), $1,600 (R-25 to R-35), $1,500 (cathedral, R-28 target) and $1,300 (cathedral, R-20 target), all after tax.
- On a $4,000 job, the rebate covers 20–31%. That is still meaningful, but no longer half.
- The least-insulated attics win twice. They get the biggest rebate and the biggest cut in heat flow.
- Going to R-60 instead of R-50 adds little cost but more comfort. The rebate is the same; the extra insulation is usually a small part of the job.
- Air leakage costs older homes more. Natural Resources Canada estimates air-leakage heat loss in a 1950s home costs about $390 a year on natural gas, versus about $280 for a home built in 2000 or later.
Method
We used the published rules of the Home Renovation Savings Program’s standalone attic path (homerenovationsavings.ca, January 5, 2026 amounts): the rebate equals 50% of the after-tax cost, up to a maximum set by the attic’s current R-value. We applied those rules to after-tax job costs from $1,000 to $5,000.
For heat flow, we used the standard relationship that heat flow through an insulation layer is proportional to 1 divided by its R-value. This is a simplified view of the insulation layer only. It does not include air leaks, framing or ventilation, and it is not an estimate of bill savings.
Air-leakage cost figures come from Natural Resources Canada.
Finding 1: where the rebate stops covering half
| Attic tier | Maximum rebate | Full rebate reached at (after tax) |
|---|---|---|
| R-12 or less → R-50 | $1,250 | $2,500 |
| Above R-12 to R-25 → R-50 | $1,000 | $2,000 |
| Above R-25 to R-35 → R-50 | $800 | $1,600 |
| Cathedral/flat roof, R-25 or less → R-28 | $750 | $1,500 |
| Cathedral/flat roof, R-12 or less → R-20 | $650 | $1,300 |
Finding 2: rebate share at different job prices
Share of the after-tax cost covered by the rebate:
| After-tax cost | R-12 or less | R-12 to R-25 | R-25 to R-35 | Cathedral (R-28) | Cathedral (R-20) |
|---|---|---|---|---|---|
| $1,000 | 50% ($500) | 50% ($500) | 50% ($500) | 50% ($500) | 50% ($500) |
| $1,500 | 50% ($750) | 50% ($750) | 50% ($750) | 50% ($750) | 43% ($650) |
| $2,000 | 50% ($1,000) | 50% ($1,000) | 40% ($800) | 38% ($750) | 32% ($650) |
| $2,500 | 50% ($1,250) | 40% ($1,000) | 32% ($800) | 30% ($750) | 26% ($650) |
| $3,000 | 42% ($1,250) | 33% ($1,000) | 27% ($800) | 25% ($750) | 22% ($650) |
| $4,000 | 31% ($1,250) | 25% ($1,000) | 20% ($800) | 19% ($750) | 16% ($650) |
| $5,000 | 25% ($1,250) | 20% ($1,000) | 16% ($800) | 15% ($750) | 13% ($650) |
What this means: if your quote is above the “full rebate” price for your tier, the rebate is fixed. Compare quotes on scope (R-value, air sealing, baffles), not on how much rebate they promise.
Finding 3: net cost after the rebate
| After-tax cost | R-12 or less | R-12 to R-25 | R-25 to R-35 |
|---|---|---|---|
| $2,000 | $1,000 | $1,000 | $1,200 |
| $2,500 | $1,250 | $1,500 | $1,700 |
| $3,000 | $1,750 | $2,000 | $2,200 |
| $4,000 | $2,750 | $3,000 | $3,200 |
Finding 4: how much heat flow each upgrade cuts
Heat flow through the attic insulation layer (simplified, insulation only):
| Starting R-value | Upgrade to R-50 | Upgrade to R-60 |
|---|---|---|
| R-12 | 76% less | 80% less |
| R-20 | 60% less | 67% less |
| R-25 | 50% less | 58% less |
| R-35 | 30% less | 42% less |
| R-50 | — | 17% less |
What this means: the first inches matter most. An attic at R-12 has far more to gain than one at R-35, which is exactly how the rebate tiers are set up.
Finding 5: older homes leak more, and it costs more
Natural Resources Canada’s estimate of the yearly cost of heat lost through air leakage, by decade built:
| Built | Natural gas | Electricity |
|---|---|---|
| 1900s | $720 | $1,570 |
| 1950s | $390 | $860 |
| 1960s | $360 | $780 |
| 1970s | $370 | $790 |
| 1980s | $360 | $780 |
| 1990s | $320 | $690 |
| 2000 to present | $280 | $610 |
Source: Natural Resources Canada. Figures are NRCan estimates from their published guide and are shown in the dollars of that publication.
What this means: air sealing the attic floor before insulating is as important as the insulation itself, especially in pre-1980 homes. See attic air sealing.
How to use this study
- Find your tier using our R-value guide.
- Look up your quote’s after-tax price in Finding 2 to see your rebate.
- If your attic is under R-25, prioritize the upgrade: you get both the biggest rebate and the biggest comfort gain.
- Ask for R-60 rather than R-50 if the price difference is small.
Citation
You are welcome to cite this study. Please link to this page: “Ontario Attic Rebate Study 2026, Pro Home Insulation.”
Frequently asked questions
How much of my attic insulation job will the Ontario rebate cover?
Exactly 50% of the after-tax cost until you reach your tier’s maximum. For an attic at R-12 or less, that happens at $2,500. Above that, the rebate stays at $1,250.
Is R-60 worth it if the rebate only needs R-50?
Usually yes. The rebate is the same, the extra depth often adds only a small part of the total price, and it cuts heat flow further. It also matches what Ontario’s building code targets for new homes.
Does this study estimate energy bill savings?
No. It looks at heat flow through the insulation layer only. Your actual savings depend on air leaks, your heating system, fuel prices and how you use your home.
Where do the rebate numbers come from?
From the Home Renovation Savings Program’s published attic rebate amounts, effective January 5, 2026. The program can change amounts at any time.
Get your rebate estimate
We measure your attic and show the exact rebate in your written quote. Call (647) 250-0606 or book online.