The Ontario Building Code | Exit Width Reduction
18.104.22.168. Exit Width Reduction
(1) Except as permitted by Sentences (2) to (4), no fixture, turnstile or construction shall project into or be fixed within the required width of an exit.
(3) Swinging doors in their swing shall not reduce the required width ofexit stairs or landings to less than 750 mm or reduce the width of an exit passageway to less than the minimum required width.
(4) handrails and construction below handrails are permitted to project into the required width of means of egress but the projections shall be not more than 100 mm on each side of the required width.
(5) In an elementary or secondary school, where a stair lift is installed in an exit stair, an intermediate handrail shall be installed between the path of travel of the stair lift and the remainder of the stair to ensure that the stair lift will not reduce the required width of the exit stair.