(1)
Except as provided in Sentence (2), the distance between a stair riser and the leading edge of a door during its swing, except for doors serving a single dwelling unit or a house with a secondary suite, shall be not less than 300 mm.
(2)
Where there is a danger of blockage from ice or snow, an exit door, including doors serving a single dwelling unit, may open onto not more than one step, provided the riser of such a step does not exceed 150 mm.