The Ontario Building Code | Height over Stairs
9.8.2.2. Height over Stairs
(1) The clear height over stairs shall be,
(a) measured vertically, over the clear width of the stair, from a straight line tangent to the tread and landing nosings to the lowest point above, and
(b) not less than,
(i) 1 950 mm for stairs serving a single dwelling unit, and
(ii) 2 050 mm for stairs not serving a single dwelling unit.
Note: On July 1, 2017, Clause 9.8.2.2.(1)(b) of Division B of the Regulation is revoked and the following substituted: (See: O. Reg. 139/17, s. 76)
(b) not less than,
(i) 1 950 mm for stairs serving a house or an individual dwelling unit, and
(ii) 2 050 mm for stairs not serving a house or an individual dwelling unit.
9.8.3. Stair Configurations
In Plain Language
A minimum clear height must be maintained over stairs, so someone walking up or down doesn't strike their head on a ceiling, beam, or other overhead obstruction.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.