Quick quiz: Ontario rebates
A few questions from the programs we track. Tap an answer to see why.
The Three Types, Straight Up
Blown-In Fiberglass
Cost installed: $1.50-$2.50 per square foot, or roughly $1,800-$3,200 for a typical 1,500-square-foot attic. R-value: about R-2.5 per inch. Best for: open, accessible attics that just need volume added.
The standard pick for topping up an attic to HRSP's R-50 minimum. Fast to install, doesn't settle much, and it's what most contractors quote by default unless you ask about alternatives.
Blown-In Cellulose
Cost installed: $1.75-$3.00 per square foot, or roughly $2,100-$3,800 for the same attic. R-value: about R-3.5 per inch. Best for: older Ontario homes where you want denser fill and better sound dampening between floors.
Recycled paper treated for fire and pest resistance, packed denser than fiberglass so it resists air movement better on its own. It settles 15-20% over the first few years, so ask your installer to account for that in the initial blow depth or you'll drift below the R-50 target HRSP requires.
Spray Foam (Closed-Cell)
Cost installed: $4.50-$8.00 per square foot for closed-cell. R-value: about R-6.5 per inch. Best for: rim joists, older stone foundation walls, and cathedral ceilings with limited depth to work with.
Ontario's older housing stock — especially century homes in Toronto, Hamilton, and Ottawa — often has rim joists and foundation transitions where blown-in material just falls through. Foam seals and insulates those specific spots in one pass. Using it on a standard open attic costs three to four times more than fiberglass for the same effective R-value.
| Type | Cost (1,500 sq ft attic) | R-value per inch | Best use |
|---|---|---|---|
| Blown-in fiberglass | $1,800-$3,200 | ~R-2.5 | Open attic top-up |
| Blown-in cellulose | $2,100-$3,800 | ~R-3.5 | Denser fill, sound dampening |
| Spray foam | Spot-priced, $4.50-$8/sq ft | ~R-6.5 | Rim joists, foundations, tight cathedral ceilings |
How the Ontario Rebate Applies
Unlike a flat provincial rate, HRSP pays more the further your attic is from code minimum. Attic and cathedral ceiling insulation need no pre-assessment:
- Starting at R-12 or below: up to $1,250, must reach R-50 minimum across the full roof assembly
- Starting at R-12-25: up to $1,000, same R-50 target
- Starting at R-25-35: up to $800, smaller gap to close
- Cathedral ceiling / flat roof: up to $750 (from R-25 to R-28 minimum) or up to $650 (from R-12 to R-20 minimum)
Wall, foundation, and crawlspace insulation sit in a separate assessment-required tier — you'll need a pre-retrofit energy assessment booked through HRSP first, but combined with attic work, a full-home project can reach $6,300 in total insulation rebates.
These tiers are provincial, so they're the same whether you're in Toronto, Ottawa, or Hamilton — check your Ontario city page for local installers, but the rebate math doesn't change by city.
What to Check Before You Buy
- Get your current R-value measured, not guessed: the rebate tier depends on your starting point, so an installer who skips this step can't quote you accurately.
- Air sealing first: HRSP's R-50 target assumes a sealed assembly. Ask whether the quote includes sealing around pot lights, the attic hatch, and top plates.
- Ventilation: Confirm baffles keep soffit vents clear once the new insulation goes in — blocked vents cause moisture problems in Ontario's humid summers and cold winters alike.
- Book the assessment early if you need walls or foundation done: HRSP's assessment-required tier can add weeks to your timeline before installation even starts.
What to Ask Before You Sign
- "What's my current R-value, and which HRSP tier does that put me in?"
- "Does this quote include air sealing, or just the insulation material?"
- "Will you file the HRSP rebate claim, or do I need to?"
- "Do I need the pre-retrofit assessment for this scope of work?"
- "Are soffit vents baffled so airflow stays open?"
The One Number That Matters
Topping up an Ontario attic from R-12 to R-50 typically cuts heating costs by 10-15%, which on an average natural gas or electric heating bill works out to roughly $150-$300 a year. Combined with the $1,250 rebate at the lowest starting tier, most single-measure attic jobs pay back their remaining out-of-pocket cost in under four years.
