The Ontario Building Code | Straight and Curved Runs in Stairs
184.108.40.206. Straight and Curved Runs in Stairs
(1) Except as provided in Sentence (2), stairs shall consist of,
(a) straight-runs, or
(2) Stairs within dwelling units shall consist of,
(c) straight-runs with winders, or
(d) straight-runs with curved-runs.