how wide must a stairway be
Stairways serving an occupant load of 50 or less may be 36 inches wide. Private stairways serving an occupant load of less than 10 may be 30 inches wide. (2) Trim shall not reduce the required width by more than 3 1/2 inches. Handrails may project from each side of a stairway a distance of 3 1/2 inches into the required width. Stringers may project 1 1/2 inches.