The Ontario Building Code | Combination Rooms
9.5.1.4. Combination Rooms
(1) Two or more areas may be considered as a combination room if the opening between the areas occupies the larger of 3 m2 or 40% or more of the wall measured on the side of the dependent area.
(2) Where the dependent area is a bedroom, direct passage shall be provided between the two areas.
(3) The opening required in Sentence (1) shall not contain doors or windows.
In Plain Language
Combination rooms, spaces serving more than one function such as a combined living and dining room, have area requirements set out in this article reflecting their dual use.
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.