The Ontario Building Code | Access to Fire Escapes
3.4.7.3. Access to Fire Escapes
(1) Access to fire escapes shall be from corridors through doors at floor level, except that access from a dwelling unit is permitted to be through a casement window having an unobstructed opening not less than 1 100 mm high by 550 mm wide with a sill height of not more than 900 mm above the inside floor.
(2) The clear area of a fire escape balcony onto which a door opens, shall be not less than 1 m2.