A new report commissioned by the Minnesota Department of Labor and Industry (DLI) concludes that single-stair multifamily buildings could be constructed at roughly twice the height and occupancy allowed under the current model code—with a small set of targeted code adjustments.
According to the draft report, released on Dec. 30, 2025, requiring smoke alarms in common means of egress for multifamily buildings taller than three stories, along with more rigorous sprinkler system maintenance, would establish a framework that allows these structures to be built beyond the limits currently permitted by the model code. Smaller apartment and condo buildings with a single stairway, commonly built on smaller lots, are limited to three stories above grade in the model code, plus a basement. Minnesota’s report shows that with these adjustments, these structures can be built much larger than the model code allows without impacting safety.
The State Legislature directed DLI to commission the study in 2024 to evaluate the safety performance of single-stair dwellings in Minnesota compared with model-code-compliant buildings. The analysis was completed by Wiss, Janney, Elstner Associates and presented to the state’s building code panel this week.
“In the first meeting, I told the group this approach could revolutionize how we prepare building codes at both the model code and local adoption levels,” said Nick Erickson, senior director of housing policy for Housing First Minnesota and industry representative on the panel. “Using data-driven decisions, building codes can be a powerful tool to increase both housing affordability and supply. This report proves what is possible when we reexamine longstanding housing regulations.”
Minnesota’s study was based on fire risk assessment, with the researchers creating a risk-informed event tree of scenarios in which existing protections may fail. Each of these was based on data on the likelihood of occurrence. Failure of the sprinkler system is tied to 97% of the overall risk to building occupants; these include no water to the system or the system failing to signal the alarm system. The two recommended changes to the building code for these structures can eliminate most of the risk associated with these structures.
“The draft findings suggest there are huge safety benefits to point access block buildings, which would make single-stair reform a win-win for both affordability and safety— not something you often see in code development discussions,” said Stephen Smith, executive director of Center for Building in North America and panel appointee. “Governments across the U.S. have taken a back seat on code development, cutting funding, and deferring instead to private organizations. This study’s cost was pennies compared to what Minnesotans pay for housing, and we’ve been penny-wise, pound-foolish in not funding more of this research. It could be just the start of finding efficiencies in our codes, if only cities, states, and the federal government would just spend a tiny bit of money to look for them.”
This report was not tied to any specific code change. The Department and the consultants will incorporated the Technical Advisory Group’s feedback into the final report, which was sent to the State Legislature for their consideration.