(1) A building classified as Group A, Division 3 is permitted to be of combustible construction or noncombustible construction used singly or in combination, provided,
(a) it is not more than 1 storey in building height, and
(b) it has a building area not more than,
(i) 1 000 m2 if facing one street,
(ii) 1 250 m2 if facing two streets, or
(iii) 1 500 m2 if facing three streets.