Michigan Governor Gretchen Whitmer signed single-stair legislation into law, removing a regulatory barrier that prevented developers from building smaller multifamily housing projects economically. The new rule allows developers to construct apartment buildings up to six stories with a single interior exit stairway, rather than requiring the dual-stairwell designs mandated under previous building codes.

Single-stair design reduces construction costs substantially. Developers eliminate expensive redundant stairwells, mechanical systems, and hallway space. These savings translate directly into lower per-unit construction expenses, making smaller projects between 20 and 80 units financially viable in midsize Michigan cities and suburbs where economics currently don't support traditional multifamily development.

Housing advocates in Michigan pushed this reform for years, citing shortage of deed-restricted affordable units and rising rents across the state. The single-stair model proves popular in other states. Oregon legalized single-stair apartments in 2018. California followed in 2021. Minnesota approved the format in 2024. Each jurisdiction reported increased multifamily development in urban neighborhoods and smaller markets that previously lacked density incentives.

For developers, the law opens underutilized sites in secondary markets. A modest six-story building now pencils out where nothing would have worked before. For renters, particularly in mid-sized Michigan towns, this means new housing supply competing downward on price. Small-unit counts appeal to local builders without major development infrastructure.

Sellers benefit too. Land parcels previously too small or shaped awkwardly for conventional multifamily now attract development offers. Owners of vacant office buildings or older commercial structures gain conversion pathways into housing.

Landlords operating existing apartments face increased competition in Michigan markets where single-stair projects emerge. Rents may stabilize or decline in those submarkets as new supply arrives.

Whitmer's signature reflects broader state