The Alberta insulation code, at the numbers a permit actually needs.

Alberta enforces the National Building Code – 2023 Alberta Edition (NBC(AE) 2023, based on NBC 2020) and the National Energy Code of Canada for Buildings 2020 (NECB 2020). Both were declared in force on 1 May 2024 by Alberta Regulation 5/2024, filed 24 January 2024. AR 5/2024 · s.1, s.6

Houses and other Part 9 buildings comply through Section 9.36 of NBC(AE) 2023. Part 3 buildings — commercial, industrial and larger residential — comply through NECB 2020. Both are adopted at Tier 1 only. AR 5/2024 · s.2, s.3

Alberta also amends Section 9.36 in four specific places, all named in the same STANDATA: window U-values in Article 9.36.2.7 are slightly relaxed against the national code; equipment performance references in Article 9.36.3.10 move to HSPF2 / SEER2 / UEF to match US supply; Sentence 9.36.5.10.(9) replaces the national two-level airtightness assumption with a single 2.5 ACH50 default; and the peak cooling load provisions of 9.36.7 do not apply at Tier 1. STANDATA 23-BCB-001

Climate zones in the Canadian codes are defined by heating degree days below 18 °C. Zone 7A is the 5000–5999 HDD18 band. The code’s own climatic table puts Red Deer at HDD18 = 5550, elevation 855 m, with a January 2.5% design temperature of −32 °C and a January 1% design temperature of −35 °C. The 1-in-50 hourly wind pressure is 0.40 kPa. NECB 2020 · Div. B, Table C-1

Environment and Climate Change Canada’s published climate normal for Red Deer A (climate ID 3025480) is 5,548.1 HDD18 — an independent number, from a different body, arriving within two degree-days of the code table. Two sources agreeing is worth more than one source quoted confidently.

The zone boundary is a commercial fact, not trivia. The same house in Brooks (4880 HDD18, Zone 6) needs a ceiling at RSI 8.67 without an HRV. In Red Deer it needs RSI 10.43. That is roughly a 20 per cent jump in required attic resistance from location alone.

Two tables apply, and which one you read depends on whether the house has a heat-recovery ventilator. Table 9.36.2.6.-A is the no-HRV column; Table 9.36.2.6.-B applies where an HRV is installed and relaxes the ceiling and wall values. Every figure is a minimum effective thermal resistance in m²·K/W.

Foundation walls, crawl space walls, slabs and heated floors are governed by Article 9.36.2.8. and Table 9.36.2.8.-A. The distinction the table draws — heated floor versus unheated, above frost line versus below — changes the required value by a factor of nearly two, and it is the detail most often missed on a basement quote.

Three further sentences change what you can build at the edges of a roof:

• Attic perimeter relief — a reduction is permitted for no more than 1 200 mm, only to the extent roof slope and the minimum venting clearance impose it, and only where the nominal thermal resistance directly above the exterior wall is not less than RSI 3.52 (R-20). NBC(AE) · 9.36.2.6.(3)
• Skylight shafts take the wall values, not the ceiling values. NBC(AE) · 9.36.2.6.(4)
• Trade-off floors — where assemblies are traded off against one another, a traded assembly must still retain at least 55% of the required RSI for walls and joist-type roofs, and 60% for other opaque assemblies. NBC(AE) · 9.36.2.11.(6)

NECB does not express the envelope as minimum RSI. It sets a maximum overall thermal transmittance, U, in W/(m²·K) — the inverse of RSI. Converting is straightforward (RSI = 1/U), and the result surprises most commercial buyers.

Two NECB wrinkles worth knowing, both rarely published. Semi-heated buildings — as defined in Sentence 1.2.1.2.(2) — read the same tables at HDD base 15 °C rather than 18 °C. For Red Deer that is 4570 HDD15, which lands in Zone 6: walls 0.240, roofs 0.138, floors 0.156. NECB 2020 · 3.2.2.2.(2) And where heating cables, pipes or membranes are embedded in the surface of an above-ground assembly, U must be no greater than 80% of the table value. NECB 2020 · 3.2.2.2.(4)

Fenestration in Zone 7A: vertical fenestration max U 1.73; skylights max U 2.41; all doors max U 1.90; access hatches nominal U ≤ 1.3. Doors are exempt from the U limit where total door area is ≤ 2% of gross wall area and door U ≤ 4.4. NECB 2020 · Tables 3.2.2.3 / 3.2.2.4

On the performance path, Alberta’s amended Sentence 9.36.5.10.(9) uses a single 2.5 ACH50 assumption at a pressure exponent of 0.67, where the air barrier system is built per Subsection 9.25.3 and Articles 9.36.2.9 and 9.36.2.10 — or the tested value from a multi-point depressurisation test. The national code’s two-level system (3.2 / 2.5 ACH50) does not apply here. STANDATA 23-BCB-001

The practical consequence: on the prescriptive path no blower door test is required at all, and on the performance path the modeller may assume 2.5 ACH50 without testing, provided the air-barrier detailing is shown to comply. A test is needed only to claim a better-than-default number. That makes a measured result a genuine differentiator rather than a box to tick — the reasoning is set out on the air barrier requirements page.

Every value in Tables 9.36.2.6 and 9.36.2.8 is an effective thermal resistance: the whole assembly, including thermal bridging through framing, air films and finishes. It is not the nominal resistance stamped on the insulation.

A 2×6 wall at 406 mm on centre is roughly 13 per cent framing by area under the code’s own framing-factor table, and that framing is a parallel heat-flow path around whatever is in the cavity. This is why an RSI 3.08 wall is not simply “RSI 3.08 of product,” and why two quotes citing the same product thickness can land on different sides of compliance depending on how the assembly is calculated.

The conversion, for reading American product literature: R = RSI × 5.678. Every bracketed R-value on this page uses it.

• NECB 2025 does not apply in Alberta. It is published by NRC, but the declared-in-force energy code for Part 3 buildings in Alberta remains NECB 2020. Code adoption is the fastest-changing fact on this page; the verification date at the top is there for a reason.
• Farm buildings are a different question entirely. Low-human-occupancy farm buildings are exempt from the building, energy and fire codes, so none of these values are requirements for them. That has real consequences for how agricultural insulation should be sold — set out on the farm building exemption page.
• This is a reading of the published code, not a permit approval. The authority having jurisdiction interprets and applies it. Variances, alternative solutions and designer judgement all sit outside these tables.