Subsection 1009.1 - Stairway width The width of stairways shall be determined as specified in Section 1005.1, but such width shall not be less than 44 inches (1118 mm). See Section 1007.3 for accessiblemeans of egressstairways.
Exceptions:
1.Stairways serving an occupant load of less than 50 shall have a width of not less than 36 inches (914 mm).2.Spiralstairways as provided for in Section 1009.9.3.Aislestairs complying with Section 1028.4. Where an incline platform lift or stairway chairlift is installed on stairways serving occupancies in Group R-3, or within dwelling units in occupancies in Group R-2, a clear passage width not less than 20 inches (508 mm) shall be provided. If the seat and platform can be folded when not in use, the distance shall be measured from the folded position.