Minnesota Residential Code: Stairs & Guards

Minnesota builds to the 2020 Minnesota Residential Code (Minnesota Rules Chapter 1309) — a statewide mandatory code that adopts the 2018 IRC by reference, as amended, effective 31 March 2020.

For a house stair, the figures match 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. No Minnesota-specific stair or guard amendment has been confirmed (cold-climate states sometimes deepen footing/frost-depth requirements, but that’s a separate provision from stair geometry and hasn’t been verified here). See the US stair & guard rules for the shared figures, and confirm against the current Chapter 1309 text for any local amendments.