According to HousingWire, Michigan's Governor Gretchen Whitmer recently signed into law a pair of bills that reform building code requirements for multifamily housing. The legislation allows developers to construct apartment buildings up to six stories with just a single interior stairwell, rather than the traditional requirement for two staircases. This change is designed to reduce construction costs and make it easier to build housing on smaller lots, particularly in dense urban neighborhoods where space is at a premium.
Michigan joins a growing list of states making this shift in building standards. Colorado, Texas, and Montana have already adopted similar single-stairway frameworks, and numerous other states are actively studying whether to follow suit. Even some individual cities have moved forward on their own, while Washington D.C. is in the process of finalizing comparable rules, and California lawmakers are considering legislation along these lines.
The law comes in two parts that work together. One bill permits single-stair buildings up to four stories, while a second extends that permission to five and six story buildings. The second measure only takes effect because the first passed, creating a structured two-tier approach. These rules are positioned as temporary measures that will sunset once Michigan formally adopts updated standards from the International Code Council.
Housing advocates believe this reform will meaningfully reduce construction expenses by freeing up floor space that would otherwise be consumed by a second stairwell. This extra space could allow developers to include more units or larger units in the same footprint, which they argue makes housing more affordable and feasible on constrained urban sites. Supporters view the law as momentum that could help advance a broader housing reform package the state is considering, though that larger effort currently faces resistance from local governments concerned about losing zoning control.
Fire safety officials nationwide have opposed these changes, contending that a second staircase provides residents with an additional escape route and gives firefighters better access during emergencies. Connecticut's experience illustrates this political challenge. The state adopted similar reform in 2024 but fire officials successfully delayed the regulatory process, and the law was ultimately repealed just months later, showing how influential these concerns can be.
What I am seeing locally here in the Bay Area is that every state action like Michigan's adds credibility to the conversation about how we might reform our own building codes. We're already dealing with constrained lots and high development costs in the East Bay and throughout our region, so when other states demonstrate that single-stairway buildings can work, it shifts the debate in California toward more practical solutions for infill housing.
