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Idaho Residential Code: Stairs & Guards
Idaho runs a statewide residential code based on the 2018 IRC — the stair and guard figures follow the IRC baseline.
Idaho builds to the Idaho Residential Code, the 2020 edition based on the 2018 IRC, adopted statewide by the Idaho Building Code Board (part of the Division of Occupational and Professional Licenses) and effective 1 January 2021.
No Idaho-specific stair or guard amendment has surfaced, so for a house stair the figures follow the IRC baseline — 7¾ in max riser, 10 in min tread, 6 ft 8 in headroom, 36 in min width, 34–38 in handrails, 36 in guards, the 30 in guard trigger and the 4 in sphere. See the US stair & guard rules for the shared figures.
Adoption status
Adopted- Current code in force
- Idaho Residential Code (2020 Edition, based on IRC 2018)
- Next edition
- —
- Adoption / transition
- Statewide, effective January 1, 2021; adopted by state statute via Idaho Building Code Board (DOPL)
Last verified 2026-07-28
No state-specific variations recorded yet for this jurisdiction.