(1) A building classified as Group A, Division 1 is permitted to conform to Sentence (2) provided,
(a) it is not more than 1 storey in building height,
(b) no part of an auditorium floor is more than 5 m above or below grade,
(c) no occupancy is above or below the auditorium other than one that serves it or is dependent on it, and
(d) the occupant load of the auditorium floor is not more than 300.
(2) The building referred to in Sentence (1) is permitted to be of combustible construction or noncombustible construction used singly or in combination, and,
(a) floor assemblies shall be fire separations with a fire-resistance rating not less than 45 min,
(b) mezzanines shall have, if of combustible construction, a fire-resistance rating not less than 45 min,
(c) roof assemblies shall have, if of combustible construction, a fire-resistance rating not less than 45 min, and
(d) loadbearing walls, columns and arches supporting an assembly required to have a fire-resistance rating shall,
(i) have a fire-resistance rating not less than 45 min, or
(ii) be of noncombustible construction, and
(e) loadbearing walls, columns and arches supporting a fire separation shall have a fire-resistance rating not less than that required for the fire separation.