(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 house or an individual dwelling unit in a house, and not less than 550 mm by 900 mm for other crawl spaces.
(2) Access 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.