Most Ontario homes built before 2000 have R-20 to R-30 attic insulation. The NRCan recommendation – and the Canada Greener Homes Grant threshold – is R-60. Upgrading from R-12 to R-60 can save $400-$900/year in a typical GTA home.
Insulation types and R-values:
- Blown cellulose: R-3.5/inch – eco-friendly, good top-up material
- Blown fiberglass: R-2.5/inch – fast install
- Spray foam (closed cell): R-6/inch – best performance, air barrier included
- Batts: R-3 to R-4/inch – DIY-friendly but poor coverage around obstructions
Critical step contractors skip: air sealing. All penetrations (pot lights, plumbing stacks, partition walls, attic hatches) must be sealed before adding insulation. An unsealed pot light can defeat R-20 of insulation around it.
Greener Homes Grant: Up to $5,600 for insulation upgrades. Requires pre- and post-retrofit EnerGuide evaluation. Budget 4-8 weeks for energy advisor bookings in the GTA.
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