Québec Construction Code: Stairs & Guards

Québec builds to the Construction Code, Chapter I — Building, which adopts the National Building Code with Québec amendments. The current edition is NBC 2020 (modified Québec), in force since 17 April 2025 and mandatory from 17 October 2026 — until then a project may still be built to the previous NBC 2015 (modified Québec) edition, so check which one applies to your start date.

For a house stair the figures match the NBC 2020 baseline — 200 mm max riser, 255 mm min run (giron), 1950 mm headroom, 860 mm min width, 865–1070 mm handrails, 900 mm guards, the 600 mm trigger and the 100 mm gap. Québec adds a few belt-and-braces rules (for example, balusters must resist a sideways load so the 100 mm gap can’t be spread open) but doesn’t change those numbers. See the Canada stair & guard rules.