The Ontario Building Code | Doors
3.4.6.11. doors
(1) The distance between a stair riser and the leading edge of a door during its swing shall be not less than 300 mm.
(2) No exit door shall open directly onto a step except that, if there is danger of blockage from ice or snow, an exit door is permitted to open onto not more than one step which shall be not more than 150 mm high.
(3) Exit doors shall be clearly identifiable.
(4) No door leaf in an exit doorway ="http://thehandyforce.com/doors/" title ="Toronto Door installer">doorway with more than one leaf shall be less than 600 mm wide.
In Plain Language
The distance between a stair riser and a swinging door's leading edge must be at least 300 mm, exit doors generally can't open directly onto a step (with a narrow snow/ice exception), and exit doors must be clearly identifiable.
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.