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.