The Ontario Building Code | Exterior Passageway Exceptions
3.4.4.3. exterior Passageway Exceptions
(1) The requirements of Sentences 3.4.4.1.(1) and 3.2.3.13.(1) and (3) do not apply to an exterior exit passageway provided,
(a) not less than 50% of the exterior side is open to the outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">doors, and
(b) an exitstair is provided at each end of the passageway.
In Plain Language
An exterior exit passageway can skip the usual fire-separation and spatial-separation requirements if at least half of its exterior side is open to the outdoors, since open-air passageways don't trap smoke the way enclosed ones do.
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.