The Ontario Building Code | Loads for Occupancy Served
4.1.5.4. Loads for Occupancy Served
(1) The following shall be designed to carry not less than the specified load required for the occupancy they serve, provided they cannot be used by an assembly of people as a viewing area:
(a) corridors, lobbies and aisles not more than 1 200 mm wide,
(b) all corridors above the first storey of residential areas of apartments, hotels and motels, and
(c) interior balconies and mezzanines.
In Plain Language
Structural elements like beams and mezzanine floors must be designed to carry at least the specified load for the occupancy they serve, provided they can't be put to some other, heavier-load use later.
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.