Notes 2 risers + 1 tread must = between 24 & 25” (not including nosing). Not more than 12’ allowed between landings. Landing depth = to stairway width. 36” minimum width for dwellings & occupant load less than 50. All other uses must be 44” wide. Handrail required if 4 or more risers for residential, 1 or more for commercial. Handrails required on both sides of all commercial stairs. Handrail height between 34” & 38” above leading edge of tread. Handrail required on one side only within dwellings (exterior stairs require handrails on each side).