New research suggests Missouri cities could allow more apartment buildings—without compromising safety—by rethinking outdated fire code requirements.
The study by the Pew Charitable Trusts and the Center for Building in North America found that small apartment buildings with one stairwell are just as safe as those with two. But Missouri’s biggest cities—Springfield, St. Louis and Kansas City—use building codes that require two stairways in buildings taller than three stories. That rule drives up construction costs and makes many projects financially unworkable.
These two-stair rules are based on the International Building Code, the widely adopted national standard. But they block a housing type common in Europe and now gaining traction in U.S. cities such as New York and Seattle.
The data challenge the logic of the two-stair mandate. In New York, none of the 4,440 single-stair apartment buildings built since 2012—each equipped with fire sprinklers—has been tied to a fire death caused by blocked exits. Seattle shows the same pattern: no increase in fatalities for single-stair buildings.
What’s changed? Modern safety systems such as sprinklers, smoke detectors, and fire-resistant stairwells have significantly improved safety in multi-unit buildings. The redundancy of a second staircase adds cost without increasing safety.
That trade-off matters. A second staircase means longer hallways, less usable space, and fewer units—especially in tight or oddly shaped lots. For developers trying to build mid-size, lower-cost housing, the extra stairwell often kills the project.
Critics may argue redundancy is good policy. But the evidence shows single-stair buildings, built to modern standards, are safe. Other states are already adapting. Washington and California have created carve-outs or pilot programs allowing single-stair buildings under certain conditions—typically height limits and requirements to use safety features like sprinklers.
Although Missouri is one of a handful of states without its own statewide codes, if our cities want to expand housing options without major subsidies or rezonings, removing outdated design rules is a practical place to start.
