The Ontario Building Code | Headroom Clearance
3.4.3.5. Headroom Clearance
(1) Except as provided by Sentences (2), (4) and (5), every exit shall have a clear height over the clear width of theexit of not less than 2 100 mm.
(2) The clear height of stairways shall be measured vertically, over the clear width of the stairway, from a straight line tangent to the tread and landing nosings to the lowest point above, and shall not be less than 2 050 mm.
(3) The clear height of landings shall be measured vertically, over the clear width of the landing, to the lowest point above.
(4) Except as permitted by Sentence (5), the clear height of doorway ="http://thehandyforce.com/doors/" title ="Toronto Door installer">doorways shall not be less than 2 030 mm.
(5) No door closer or other device shall be installed so as to reduce the clear height of a doorway ="http://thehandyforce.com/doors/" title ="Toronto Door installer">doorway to less than 1 980 mm.
3.4.4. Fire Separation of Exits
In Plain Language
Every exit generally needs a clear height of at least 2,100 mm over its full width, with stairway headroom measured vertically from a line tangent to the tread and landing nosings, ensuring taller occupants don't have to duck to escape.
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.