341. Buildings for which the occupancy, in addition to one or more of the occupancies exempted under paragraphs 1, 3, 4, 5 and 6 of section 340, is one of the following occupancies, are also exempted from the application of this Chapter:(1) a building used as a dwelling unit that has a building height of no more than 2 storeys or contains no more than 8 dwelling units;
(2) a mercantile occupancy having a total floor area of no more than 300 m2;
(3) a business and personal services occupancy having a building height of no more than 2 storeys.