Find your city
| City | Province | HDD18 (approx.) | Zone |
|---|---|---|---|
| Regina | SK | ~5,000–5,300 | 7A |
| Saskatoon | SK | ~5,300–5,700 | 7A |
| Winnipeg | MB | 5,670 | 7A |
| Brandon | MB | 5,760 | 7A |
| Thunder Bay | ON | 5,650 | 7A / ON Zone 2 |
| Kenora | ON | 5,630 | 7A / ON Zone 2 |
| Dryden | ON | 5,850 | 7A / ON Zone 2 |
Zone 7A prescriptive requirements (NBC 9.36, Manitoba & Saskatchewan)
| Assembly | No HRV | With HRV |
|---|---|---|
| Ceilings below attics | RSI 10.43 (R-59.2) | RSI 8.67 (R-49.2) |
| Cathedral ceilings / flat roofs | RSI 5.02 (R-28.5) | RSI 5.02 (R-28.5) |
| Above-grade walls | RSI 3.08 (R-17.5) | RSI 2.97 (R-16.9) |
| Floors over unheated spaces | RSI 5.02 (R-28.5) | RSI 5.02 (R-28.5) |
| Foundation walls | RSI 3.46 (R-19.7) | RSI 2.98 (R-16.9) |
| Slab-on-grade w/ integral footing | RSI 3.72 (R-21.1) | RSI 2.84 (R-16.1) |
| Rim joists | RSI 3.08 (R-17.5) | RSI 2.97 (R-16.9) |
For Zone 7B (colder locations further north, such as The Pas, Flin Flon, or much of the boreal north) the above-grade wall requirement steps up further, to RSI 3.85 (R-21.9) without an HRV, a jump of more than R-4 over Zone 7A.
Ontario's Thunder Bay/Kenora/Dryden requirements run through SB-12 Zone 2, a parallel but not identical system to NBC 9.36. See the provincial table below rather than reading the Zone 7A table above as directly binding in Ontario.
Provincial adoption status (mid-2026)
| Province | Code base | Effective date | Energy tier (mid-2026) |
|---|---|---|---|
| Saskatchewan | NBC/NECB 2020 | Jan 1, 2024 | Tier 1 (rolled back from a planned Tier 3, Feb 2025) |
| Manitoba | NBC/NECB 2020 (MECB) | Jan 1, 2024 | Tier 1 (residential & commercial) |
| Ontario | OBC 2024 (SB-10/SB-12) | Jan 1, 2025 | Two-zone system (5,000 HDD line); Zone 2 covers NW Ontario |
What "Tier 1" means for a homeowner
Saskatchewan planned to move toward Tier 2 and Tier 3 (deeper efficiency standards), then reversed course in February 2025 and rolled residential construction back to Tier 1, the base-code minimum, citing housing affordability. Manitoba has stayed at Tier 1 throughout. In practical terms: the regulatory floor in this region is not currently being pushed upward. A home built to exactly what code requires is being built to the legal minimum, not a durability or comfort target, which is exactly why "beyond code" is a real, meaningful distinction here, not a marketing phrase.
Frequently asked questions
What R-value is required for exterior walls in Manitoba and Saskatchewan?
Zone 7A (which covers Regina, Saskatoon, Winnipeg, Brandon, Thunder Bay, Kenora, and Dryden) requires an effective RSI 3.08 (R-17.5) for above-grade walls without a heat-recovery ventilator, or RSI 2.97 (R-16.9) with one installed.
Is Saskatchewan still requiring higher-tier energy efficiency?
No. Saskatchewan initially planned to move to Tier 2 in 2024 and Tier 3 in 2025, then delayed Tier 3 to 2026, then in February 2025 rolled Part 9 residential construction back to Tier 1, the NBC base-code minimum, citing affordability. As of mid-2026, Tier 1 is the enforced floor.
Does Ontario use the same climate zone system as Manitoba and Saskatchewan?
No. Ontario has not adopted NBC Section 9.36; it regulates energy efficiency through its own Supplementary Standard SB-12, which splits the province into two zones at a 5,000 heating-degree-day threshold. Thunder Bay, Kenora, and Dryden fall in the colder Zone 2, which carries higher requirements than the Zone 1 standard written for Toronto and southern Ontario.
Building to code minimum, or beyond it?
We'll show you what "beyond code" actually costs and saves in this climate.
