Single-staircase reforms aim to boost middle-scale housing in Michigan
Michigan Governor Gretchen Whitmer signed two bills last month amending the state building code to allow more multi-family buildings to use single-stair designs. One bill raises the allowable height for single-stair buildings from three to four stories, while the other permits single-stair buildings up to six stories in areas served by certified fire departments. The state says this is expected to reduce construction costs by over 10% and increase housing type diversity. The reform comes as seven states have passed similar measures in 2025, though fire departments remain divided on single-stair safety.
Dive Brief:
- Michigan Gov. Gretchen Whitmer signed two bills last month that update the state’s construction code to allow for single staircases in more multifamily buildings.
- One bill increases the number of stories in buildings permitted to have a single staircase from three to four, while the other allows for single staircases in buildings with fewer than six stories that are served by an accredited fire department.
- The reforms are expected to reduce construction costs by upwards of 10% and open up a more diverse range of housing options, according to a state press release.
Dive Insight:
More states and local governments are exploring building code reforms with the aim of making housing development faster and cheaper.
Some housing advocates have painted single-staircase reform, an alternative to longstanding two-staircase requirements, as a way to unlock more “missing middle” housing — mid-size multifamily housing structures that are smaller than many apartment buildings but larger than single-family homes.
In 2025, seven states enacted single-staircase reform measures.
The debate over fire safety stemming from single-staircases continues, however. While some studies have shown single-staircase apartment buildings maintain strong records of fire safety, a March report from the California Office of the State Fire Marshal urged caution. “The presence of an additional exit is important for maintaining safety in the face of unforeseen failures, fire spread, or structural compromise,” the report stated.