The Ontario Building Code | Full and Partial Loading
4.1.7.3. Full and Partial Loading
(1) buildings and structural members shall be capable of withstanding the effects of,
(a) the full wind loads acting along each of the two principal horizontal axes considered separately,
(b) the wind loads as described in Clause (a) but with 100% of the load removed from any portion of the area,
(c) the wind loads as described in Clause (a) but considered simultaneously at 75% of their full value, and
(d) the wind loads as described in Clause (c) but with 50% of these loads removed from any portion of the area.