Section 1603
SECTION 1603. Glazing of Openings. (a) Doors, sashes and framed openings in exterior walls of all buildings except Types IV and V Constructions may be glazed or equipped with approved plastics: Provided, that: (1) The wall in which such glazing is installed is so located that openings are not required to be fire-protected. (2) Except for Type I Construction, the location size, and spacing of such glazed openings do not exceed the values set forth by the Secretary. (3) Plastic used in glazed openings for Type II Construction shall be materials appropriate for use according to flame-spread characteristics and the location, size, and spacing of the openings do not exceed the values set forth by the Secretary.