The Ontario Building Code | Access Openings
18.104.22.168. Access openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings
(1) An access opening of not less than 500 mm by 700 mm shall be provided to each crawl space where the crawl space serves a single dwelling unit, and not less than 550 mm by 900 mm for other crawl spaces.
Note: On July 1, 2017, Sentence 22.214.171.124.(1) of Division B of the Regulation is amended by striking out "single dwelling unit" and substituting "houseor an individual dwelling unit in a house". (See: O. Reg. 139/17, s. 122)
(2) Access openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings shall be fitted with a door or hatch, except when the crawl space is heated and the access opening into the crawl space is from the adjacent heated space.