The Ontario Building Code | Heated and Unheated Crawl Spaces
18.104.22.168. Heated and Unheated Crawl Spaces
(1) Crawl spaces shall be considered to be heated where the space,
(a) is used as a warm air plenum,
(b) contains heating ducts or heating pipes that are not sealed and insulated to minimize heat loss to the space, or
(c) is not separated from heated space in accordance with Section 9.25.
(2) Heating of heated crawl spaces shall conform to Section 9.33.
(3) insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation, an air barrier system and a vapour barrier shall be installed in the walls of heated crawl spaces in accordance with Section 9.25.