The Ontario Building Code | Floor Numbering
3.4.6.19. floor Numbering
(1) Arabic numerals indicating the assigned floor number shall,
(a) be mounted permanently on each side of doors to exit stair shafts,
(b) be not less than 60 mm high, raised approximately 0.7 mm above the surface,
(c) be located 1 500 mm from the finished floor, and
(d) be contrasting in colour with the surface to which they are applied.
(2) Upper case letters indicating the designation assigned to each exit stair shaft shall be mounted permanently on each side of doors to the exit stair shaft and shall,
(a) be not less than 60 mm high, raised approximately 0.7 mm above the surface,
(b) be located 1 500 mm from the finished floor, and
(c) be contrasting in colour with the surface on which they are applied.
3.4.7. Fire Escapes
In Plain Language
Floor numbers must be permanently mounted on each side of exit stair shaft doors, at least 60 mm high, raised slightly off the surface, positioned 1,500 mm above the floor, and in a contrasting colour, helping both occupants and firefighters orient themselves in a stairwell.
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.