The Ontario Building Code | Ventilation of Rooms and Spaces
9.32.1.3. ventilation of Rooms and Spaces
(1) Except as permitted in Sentence (2), rooms or spaces in a dwelling unit shall be ventilated by natural means in accordance with Subsection 9.32.2.
Note: On July 1, 2017, Sentence 9.32.1.3.(1) of Division B of the Regulation is amended by striking out "dwelling unit" and substituting "residential occupancy". (See: O. Reg. 139/17, s. 125)
(2) The natural ventilation of rooms or spaces required in Sentence (1) may be provided by mechanical means.
(3) Where a room or space is not provided with natural ventilation as described in Sentence (1), mechanical ventilation shall be provided to exhaust inside air from or to introduce outside air to that room or space at the rate of one-half air change per hour if the room or space is mechanically cooled in summer, and one air change per hour if it is not.
9.32.2. Natural ventilation
In Plain Language
Rooms and spaces within a dwelling need ventilation meeting the requirements set out in this article, whether achieved naturally or mechanically.
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.