The Ontario Building Code | Group A, Division 2, 1 Storey
3.2.2.28. Group A, Division 2, 1 Storey
(1) A building classified as Group A, Division 2 is permitted to be of combustible constructionor noncombustible construction used singly or in combination, provided,
(a) it is not more than 1 storey in building height, and
(b) except as permitted by Sentence (2), it has a building area not more than,
(i) 400 m2 if facing one street,
(ii) 500 m2 if facing two streets, or
(iii) 600 m2 if facing three streets.
(2) In a building referred to in Sentence (1) without a basement, the building area limits of Sentence (1) are permitted to be doubled provided a fire separation with a fire-resistance rating not less than 1 h is used to separate the buildinginto fire compartments, each one of which does not exceed the area limits of Clause (1)(b).