The Ontario Building Code | Stairways
9.34.2.3. Stairways
(1) Every stairway shall be lighted.
(2) Except as provided in Sentence (3), 3-way wall switches located at the head and foot of every stairway shall be provided to control at least one lighting outlet with fixture for stairways with four or more risers in dwelling units.
Note: On July 1, 2017, Sentence 9.34.2.3.(2) of Division B of the Regulation is amended by striking out "dwelling units" and substituting "a house or an individual dwelling unit". (See: O. Reg. 139/17, s. 130)
(3) The stairway lighting for basements that do not contain finished space or lead to an outside entrance or built-in garage and that serve not more than one dwelling unit is permitted to be controlled by a single switch located at the head of the stairs.
In Plain Language
Stairways need lighting meeting the requirements set out in this article, ensuring safe visibility on this common trip-and-fall hazard area.
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.