Insulation costs $1.50–$5.50 per square foot installed depending on the type and where it's going. A full attic insulation upgrade for a typical home runs $1,500–$4,000 with blown-in cellulose or fibreglass, while spray foam insulation for a whole house can cost $5,000–$15,000+. The right insulation pays for itself through lower heating and cooling bills — often within 3–7 years.
Insulation is one of the highest-ROI upgrades you can make before or alongside a heat pump installation. Better insulation means a smaller heat pump, lower operating costs, and more comfortable rooms. Many provincial rebate programs cover insulation upgrades alongside heat pumps. See our heat pump rebates guide for current incentives.
Use the insulation calculator to figure out how much material you need for your project.
| Type | Cost / Sq Ft (Installed) |
|---|---|
| Blown-in fibreglass | $1.50–$2.50 |
| Blown-in cellulose | $1.50–$2.50 |
| Fibreglass batts | $1.00–$2.00 |
| Mineral wool batts (Rockwool) | $1.50–$2.50 |
| Open-cell spray foam | $1.50–$3.00 |
| Closed-cell spray foam | $3.00–$5.50 |
| Rigid foam board (EPS/XPS/polyiso) | $1.50–$3.50 |
| Spray-in-place foam (kit) | $2.00–$3.50 |
Costs include labour and material for professional installation. DIY fibreglass batts run $0.50–$1.00/sq ft in materials only.
| Scenario | Typical Cost |
|---|---|
| Top-up existing (add R-20 to R-30) | $800–$1,800 |
| Full attic (1,000 sq ft to R-50/R-60) | $1,500–$3,500 |
| Full attic with air sealing | $2,500–$5,000 |
| Spray foam attic (roof deck) | $4,000–$10,000 |
Attic insulation is the single most cost-effective energy upgrade for most homes. Heat rises — an under-insulated attic is like leaving a window open on your roof. Most pre-2000 Canadian homes have R-20 to R-30 in the attic. Current code calls for R-50 to R-60 depending on climate zone.
| Scenario | Typical Cost |
|---|---|
| Blow-in to existing walls (drill and fill) | $2,000–$5,000 |
| Batt insulation (during renovation) | $1,500–$3,500 |
| Spray foam (during renovation) | $3,000–$8,000 |
| Exterior continuous insulation | $5,000–$15,000 |
Wall insulation in an existing home is tricky because the walls are closed. Drill-and-fill with blown cellulose is the most common retrofit — small holes are drilled from outside or inside, insulation is blown in, and the holes are patched. It's not perfect (you can't air seal, and you're guessing at cavity depth) but it's dramatically better than empty walls.
| Scenario | Typical Cost |
|---|---|
| Basement walls — rigid foam + framing | $3,000–$7,000 |
| Basement walls — spray foam | $3,000–$8,000 |
| Crawl space — encapsulation + insulation | $3,000–$8,000 |
| Rim joist (band joist) — spray foam | $500–$1,500 |
Basement insulation is often overlooked but basements can account for 20–30% of a home's heat loss. Rim joists (the wood band where the floor meets the foundation) are the leakiest spot in most houses and one of the cheapest to fix with spray foam.
| Scenario | Typical Cost |
|---|---|
| Garage door insulation kit | $150–$400 |
| Garage walls + ceiling (batts) | $1,500–$3,500 |
| Garage conversion (full insulation + vapour barrier) | $3,000–$7,000 |
| Climate Zone | Attic |
|---|---|
| Zone 4 (mild) | R-38 to R-49 |
| Zone 5 (moderate) | R-49 to R-60 |
| Zone 6 (cold) | R-49 to R-60 |
| Zone 7 (very cold) | R-60+ |
These are based on current building code minimums (NBC 2020 for Canada, IECC 2021 for US). Older homes are almost always below these levels. Upgrading to current code minimums is where the biggest energy savings come from.
If you're installing or already have a heat pump, insulation directly affects your system's performance and cost.
Smaller system needed. Better insulation reduces your home's heat loss, which means a smaller (cheaper) heat pump can do the job. Dropping from R-20 to R-50 in the attic can reduce your required heat pump size by half a ton to a full ton — that's $1,000–$3,000 less in equipment cost.
Lower operating costs. A well-insulated home needs less energy to heat, so your heat pump runs fewer hours. This can reduce heating bills by 20–40% on top of the savings from switching to a heat pump.
Better comfort. Insulation eliminates cold spots, drafts, and rooms that are always too hot or cold. This makes heat pump heating more even and comfortable.
Rebate stacking. Many provinces offer insulation rebates alongside heat pump rebates. In BC, you can get up to $3,000 for insulation through CleanBC. Ontario's HER+ program covers insulation upgrades. The federal Greener Homes Grant (if renewed) covered up to $5,000 for insulation. Always insulate first, then size your heat pump — the energy audit will show a lower heat loss number, which qualifies you for a smaller and cheaper system.
Use our heat pump savings calculator to see how insulation affects your heating costs, and our heat pump size calculator to see how it affects system sizing.
| Type | DIY Cost (materials) | Professional (installed) |
|---|---|---|
| Fibreglass batts (attic) | $0.50–$1.00/sq ft | $1.00–$2.00/sq ft |
| Fibreglass batts (walls, during reno) | $0.50–$1.00/sq ft | $1.50–$2.50/sq ft |
| Blown-in (attic) | $0.75–$1.25/sq ft | $1.50–$2.50/sq ft |
| Blown-in (walls, drill & fill) | — | $2.00–$4.00/sq ft |
| Spray foam | — | $1.50–$5.50/sq ft |
| Rigid foam board (basement walls) | $1.00–$2.00/sq ft | $2.00–$3.50/sq ft |
| Rim joist spray foam (kit) | $1.50–$2.50/sq ft | $3.00–$5.00/sq ft |
Best DIY projects: Attic batt insulation, attic blown-in (rent the blower from Home Depot — it's free or nearly free with a minimum insulation purchase), rigid foam board on basement walls, and rim joist spray foam kits. These are straightforward, save significant money, and don't require specialized skills.
Leave to pros: Wall drill-and-fill, full spray foam jobs, anything involving vapour barrier details in cold climates, and any attic with knob-and-tube wiring (requires electrician first). Spray foam equipment costs $15,000+ and requires training to apply correctly.
A full attic insulation job for 1,500 sq ft typically costs $1,500–$3,500 for blown-in cellulose or fibreglass to R-50 or R-60. Adding air sealing (recommended) brings the total to $2,500–$5,000. If you're just topping up existing insulation from R-20 to R-50, expect $800–$2,000. DIY blown-in with a rented blower costs $500–$1,000 in materials.
Closed-cell spray foam costs 2–3× more than blown-in or batts but provides the highest R-value per inch (R-6.5), acts as both an air barrier and vapour barrier, and adds structural rigidity. It's worth the premium in basements (where moisture control matters), rim joists, and cathedral ceilings where space is limited. For standard attics with room for depth, blown-in insulation gives you more R-value per dollar.
Insulate first if possible. Better insulation reduces your home's heat loss, which means you need a smaller heat pump — saving $1,000–$3,000 on equipment. It also lowers operating costs by 20–40%. If you've already installed a heat pump, insulating afterward still saves money on operating costs, but you may end up with a slightly oversized system. Either way, insulation improves comfort and reduces energy use.
Yes — drill-and-fill insulation injects blown cellulose or dense-pack fibreglass through small holes drilled in the drywall or exterior siding. The holes are then patched. It costs $2,000–$5,000 for a typical home and is the most common wall insulation retrofit. It's not as thorough as insulating open walls during a renovation (you can't air seal), but it's dramatically better than empty wall cavities.
For most of southern Canada (climate zones 5–6), aim for R-50 to R-60 in the attic, R-20 to R-27 in walls, and R-15 to R-20 in the basement. For the prairies and northern Canada (zone 7), go higher — R-60+ in the attic and R-27 to R-35 in walls. In milder areas like Vancouver (zone 4), R-38 to R-49 in the attic and R-13 to R-15 in walls meets current code. Check the R-value table above for specific requirements.
Most insulation types last 20–30+ years with no maintenance. Fibreglass batts can compress or sag over time if installed vertically in walls, reducing effectiveness. Cellulose can settle 10–20% in attics over the first few years (installers typically overfill to account for this). Spray foam and rigid foam board are the most stable and longest-lasting. The main threats to insulation lifespan are moisture damage, pest intrusion, and renovation disturbance — not the insulation breaking down itself.