3.1.5.4.Combustible Windows, Glazing and Skylights

(1) Combustible skylight assemblies are permitted in a building required to be of noncombustible construction if the assemblies have a flame-spread rating not more than (a) 150 provided the assemblies (i) have an individual area not more than 9 m2, (ii) have an aggregate horizontal projected area of the openings through the ceiling not more than 25% of the area of the ceiling of the room or space in which they are located, and (iii) are spaced not less than 2.5 m from adjacent assemblies and 1 200 mm from required fire separations, or (b) 75 provided the assemblies (i) have an individual area not more than 27 m2, (ii) have an aggregate horizontal projected area of the openings through the ceiling not more than 33% of the area of the ceiling of the room or space in which they are located, and (iii) are spaced not less than 1.2 m from adjacent assemblies and from required fire separations. (See Note A-3.1.5.4.(1)) (2) Combustible vertical glazing installed no higher than the second storey is permitted in a building required to be of noncombustible construction. (3) Except as permitted by Sentence (4), the combustible vertical glazing permitted by Sentence (2) shall have a flame- spread rating not more than 75. (4) The flame-spread rating of combustible glazing is permitted to be not more than 150 if the aggregate area of glazing is not more than 25% of the wall area of the storey in which it is located, and (a) the glazing is installed in a building not more than 1 storey in building height, (b) the glazing in the first storey is separated from the glazing in the second storey in accordance with the requirements of Article 3.2.3.17. for opening protection, or (c) the building is sprinklered throughout. (5) Combustible window sashes and frames are permitted in a building required to be of noncombustible construction, provided they are vertically non-contiguous between storeys.