Glossary · Climate

NBC climate zone (Canada)

Also called: climate zone · climate zones · NBC zone · building climate zone · NECB climate zone · zone 6

Canada's building code climate zones, set by heating degree days: zone 4 (mildest) to zone 8 (coldest), with zone 7 split into 7A and 7B.

What it means

The National Building Code and the National Energy Code for Buildings group locations by annual heating degree days below 18°C, and energy requirements such as insulation levels get stricter in colder zones. Provinces adopt or adapt these codes, and some publish their own zone maps.

Why it matters in an audit

Your zone sets code-minimum insulation and window levels for renovations and additions and helps size heating equipment.

Typical numbers

Reference values with their sources. Your energy advisor’s report gives the figure for your own house.

What	Value	Source
Zone thresholds (heating degree days, °C)	Zone 4: under 3,000; zone 5: 3,000–3,999; zone 6: 4,000–4,999; zone 7A: 5,000–5,999; zone 7B: 6,000–6,999; zone 8: 7,000 or more	climatedata.ca ↗
Code example: Edmonton new homes (NBC(AE) 2023 prescriptive path)	Attic ceiling RSI 10.43 (R-59) without an HRV or RSI 8.67 (R-49) with one; windows U-value 1.61 W/m²·K or less	edmonton.ca ↗

In Canada

NRCan's older retrofit guide, Keeping the Heat In, uses its own zones A–D for insulation advice; these don't match the NBC zones.

Sources

Learn more here

Related terms

Heating degree days (HDD) A measure of how cold a place is: each day adds how far its average temperature falls below 18°C. More degree-days means more heating.
R-value How well a material resists heat flow; higher is better, and insulation is rated with it, such as R-20 for walls or R-50 for attics.
RSI (metric R-value) The metric version of R-value used in Canada; multiply RSI by 5.678 to get R, so RSI 8.8 is about R-50.
U-factor (U-value) How fast heat passes through a window, door or wall assembly; lower is better, the opposite of R-value.
Heating-dominated vs cooling-dominated climate Whether a place needs more energy for heating or for cooling over a year, which changes which upgrades and equipment matter most.
National Building Code of Canada (NBC) Canada's model building code; once a province or territory adopts it, it sets minimum insulation, ventilation and safety rules for new homes and renovations.

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