The Ontario Building Code | Design Indoor Air Temperatures

6.2.1.2. design Indoor Air temperatures

(1) buildings classified as Group B, Division 2 or 3 occupancies or Group C residential occupancies that are intended for use in the winter months on a continuing basis shall be insulated and be equipped with heating facilities that are capable of maintaining an indoor air temperature of 22°C at the outside winter design temperature referred to in Article 6.2.1.7.

(2) All other buildings intended for occupancy in the winter months on a continuing basis should be insulated and shall be equipped with heating facilities to maintain a minimum indoor air temperature of 18°C or commensurate with the use of the building at the outside winter design temperature described in Article 6.2.1.7.