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Wall Assembly Comparison Calculator Ontario (2026): 2×6 Batts, Exterior Foam, Flash and Batt, Full Spray Foam, Double Stud and ICF Compared by Installed Cost, Effective R-Value and Heating Cost
Insulation & Air SealingFree Calculator
Which Wall Is Worth It? The Same House Seven Ways, With the Studs Counted, the Fuel Bill Attached and the Twenty-Year Number Beside the Price.
2×6 batts, batts plus exterior foam, 2×4 plus exterior foam, flash and batt, full foam, double stud, ICF. Installed insulation cost, effective R, heat through the walls per winter in gas, propane, heat pump or baseboard dollars, and the 20-year total. No email address required.
An R-22 batt in a 2×6 wall is not an R-22 wall. A quarter of that wall is wood, and wood is about R-1.2 an inch, so the wall as built is about R-17, and the heat-loss calculation and the SB-12 form both know it even if the brochure does not. Every assembly below is priced at what the insulation package costs installed in Ontario this month and rated at what it does with the framing counted. Then the heat going through the walls is turned into your fuel and added up for twenty years, which is the only number that tells you whether the dearer wall is the cheaper one.
Step-by-step
Wall Assembly Comparison (Ontario)
1
The house
Perimeter x wall height per storey, less windows and doors. A 2,000 sq ft two-storey has about 2,200 to 2,600. How to measure it.
Delivered cost per million BTU of heat, Ontario October 2026, all-in. Change the fuel and watch the order change.
Fuel held at today’s price; no interest, no inflation. Keep it simple and argue about the rest.
2
Where is the house?
Material costs the same everywhere; labour does not, and insulation is mostly labour, a truck and two men in a crawlspace.
Used only to tell you whether the house is in our direct service area. Not stored.
Enter a postal code to see service coverage.
BuildersOntario.com
Seven Walls, One House
Illustrative Ontario comparison
| Assembly | Insulation installed | Effective R | Heat through walls, per winter | 20-year total |
|---|
Best value over 20 years$0
Example only. Insulation package installed in open framing at BuildersOntario budgeting rates checked October 2026, before HST: batts, poly or smart vapour retarder, exterior foam board with tape, spray foam by the board foot with masking, dense-pack cellulose. Framing, sheathing, house wrap, cladding and drywall are not included and are not the same for every assembly: a 2×4 wall is cheaper to frame than a 2×6, a double-stud wall is two walls, and an ICF wall replaces the framing, sheathing and insulation together, so its insulation line is zero and its wall cost lives on the ICF pages. Effective R-values are typical published figures for 16 in. on centre framing with a 23% framing factor; heat through the walls is a simple degree-day estimate for conduction only, no air leakage, no windows, no solar, and real bills differ. The stamped heat-loss calculation for the house governs equipment sizing, not this page.
Request a Real Quotation
Your wall area and the assembly you lean toward become a written scope an insulation contractor, or a builder pricing the whole house, can quote without guessing what you meant by “a well-insulated wall”. It goes straight to our inbox, and a copy comes back to you; reply to that copy with the house plans or a sketch with the wall heights, and the window schedule if there is one.
What this calculator does, and what it will not do!
It prices the insulation package for seven walls at this month’s installed rates, rates each wall at its effective R with the framing counted, and runs the heat through the walls in your fuel for ten, twenty or thirty winters. The twenty-year column is the one to read: it is the only place a $5.50 wall and a $2.00 wall meet on equal terms.
It does not price the whole wall. A 2×4 wall is cheaper to frame than a 2×6, a double-stud wall is two walls, and an ICF wall is a different thing entirely: the framing, sheathing, insulation and vapour barrier in one pour. So the ICF row shows zero for insulation and sends you to the ICF pages for the wall. It also ignores air leakage, which is the bigger number in most old houses; the blower door decides that one. This is a comparison; the stamped heat-loss design and the builder’s quote are the numbers you sign.
A rule of thumb: on a 2,400 sq ft wall in Simcoe County on natural gas, the walls lose about $350 a winter at R-17 and about $280 at R-21.5; the exterior foam that gets you there costs about $8,400 more and pays back in a long time. On propane the same foam saves about $210 a year and pays back in the life of the siding. On the ICF houses I build, the question does not come up: R-24 continuous is what the wall is.
How I price it
| Assembly | Insulation installed | Effective R | Notes |
|---|---|---|---|
| A. 2×6, R-22 batt, poly | $2.00 per sq ft | R-17 | Fibreglass $1.50 + poly $0.50. Mineral wool makes it $2.90. The SB-12 R-22 package wall. |
| B. A plus 1 in. exterior XPS | $5.50 | R-21.5 | Continuous R-5 outside the studs. Jamb extensions and strapping on a re-side; built in on a new house. Exterior insulation. |
| C. 2×4, R-14 batt, poly, 1.5 in. exterior XPS | $6.10 | R-18 | Thinner wall, R-7.5 outside. The framing saving is not in this table. |
| D. Flash and batt | $3.75 | R-19 | 2 in. closed cell on the sheathing ($2.50) plus R-14 batt ($1.10) and masking. No poly. The hybrid wall. |
| E. Full closed cell, 5.5 in. | $6.90 | R-24 | R-31 in the cavity, R-24 as a wall. The studs do not care what is between them. |
| F. Double stud, 12 in. cellulose | $8.40 | R-40 | Second wall $3.00, dense pack $4.50, smart retarder $0.90. The passive-house frame wall. |
| G. ICF, 6 in. core | in the wall | R-24 | 2.5 in. EPS each face, continuous, no poly, no bridging; 8 in. cores and thicker foam go to R-30 and up. ICF R-value. |
Effective R from the usual published framing-factor tables at 23% framing, 16 in. on centre. The effective R-value page shows the arithmetic. Fuel: gas about $13.50 per million BTU delivered through a 95% furnace, propane about $38.50, a cold-climate heat pump about $17.60 at a seasonal COP of 2.5, baseboard about $44, Ontario October 2026.
Where homeowners go wrong
- Reading the batt label as the wall number. R-22 on the bag, R-17 in the wall. The heat-loss calculation uses R-17, and so should you. Nominal vs effective.
- Paying for R-31 of foam and getting R-24 of wall. Full-depth foam in a stud wall is the dearest way to a modest number. Two inches of foam and a batt does most of it for half.
- Comparing walls on gas prices and then heating with propane. Change the fuel in the box. In a propane house every point of R is worth three times what it is on gas.
- Adding insulation to ICF. I see it specified. The wall is already continuous R-24; the money belongs in the windows, the attic and the air sealing. Why not.
- Forgetting the air. None of these rows includes leakage, and leakage is where the old house loses. Test it. What sealing costs.
Questions people ask
What is the best wall insulation for a new house in Ontario?
For a frame house, a 2×6 R-22 wall with 1 to 1.5 in. of continuous exterior foam (row B) is the best money in most of southern Ontario: it meets SB-12 comfortably, breaks the thermal bridge and costs about $5.50 a square foot for the insulation. On propane or electric heat, more exterior foam or a double-stud wall starts to pay. The ICF houses I build get R-24 continuous without any of that conversation.
Is spray foam in the walls worth it?
Full-depth closed cell, usually not: about $6.90 a square foot for an R-24 wall when a batt plus exterior foam gets to R-21.5 for $5.50. Two inches of foam on the sheathing plus a batt (flash and batt) is the version that earns its keep, because the foam does the air sealing and the batt does the cheap R. Foam by the board foot.
What R-value does an ICF wall have?
A standard 6 in. core form with 2.5 in. of EPS each side is about R-22 to R-24 effective, and because there are no studs it is the same R across the whole wall. Thicker-foam forms and 8 in. cores run R-30 and up. Nothing is added inside or outside. ICF R-value.
How much heat do walls actually lose?
Less than people think and more than the windows people obsess over, in a tight house. On a 2,400 sq ft wall at R-17 in Simcoe County, about 26 million BTU a winter, which is about $350 of gas or $1,000 of propane. Air leakage through the same wall in a 1970s house can be more than the conduction. The heat-loss calculator does the whole house.
Does the comparison include the framing and the cladding?
No. It compares the insulation package only, because that is what changes between the rows. A 2×4 wall saves framing money that row C does not show, and ICF replaces the framing altogether. For the whole-wall number, price the house two ways with a builder, or start with the cost to build.
Building new?
The $249 insulation takeoff measures every assembly off your plans, attic, walls, basement, rim and slab, at these rates, with the SB-12 numbers each one needs and a scope to send to three contractors. If you already have quotes, the $99 quote review puts them on one grid.
