ANSI/AWI SMA 0643-2021 - Wood Stair, Handrail, and Guard Systems
3.3 Structural
a) Residential stairways, handrails, and guard systems in one- or two-family homes of no more than three stories with separate means of egress shall be built as designed by the engineer of record or in accordance with the design approved by the authority having jurisdiction to enforce the applicable code of the jurisdiction. Where no code exists and/ or is enforced, the design shall comply with the live load requirements specified in the International Residential Code (latest edition) as published by the International Code Council.
b) Residential and other stairways, handrails, and guard systems in all other occupancies shall be built as designed by the engineer of record or in accordance with the design approved by the authority having jurisdiction to enforce the applicable code of the jurisdiction. Where no code exists and/or is enforced the design shall comply with the live load requirements in the International Building Code (latest edition) as published by the International Code Council.