MI HB5570

Multiple-family dwellings up to 4 stories (or 3 stories with an occupiable roof) may be built with a single interior exit stairway instead of the typically required two stairways under certain conditions.

Buildings must have no more than 4 units per level and a maximum net floor area of 4,000 square feet per level, with exit access travel distance limited to 125 feet from the most remote point.

Required fire safety systems include a manual fire alarm, automatic smoke detection with occupant notification, and smoke detectors in all common spaces including corridors, stairways, laundry rooms, and mechanical rooms.

Automatic sprinklers in the interior exit stairway must comply with NFPA 2025 standards for combustible stairways, regardless of actual construction type.

Elevators cannot open into the single exit stairway enclosure, and no electrical receptacles are permitted within the stairway.