Massachusetts moves to reconsider two-staircase rule for midrise apartments amid housing supply push

A building-code change under review

Massachusetts has launched a formal review of a long-standing building-code requirement that most midrise apartment buildings include two separate staircases. On February 12, 2026, Gov. Maura Healey signed an executive order initiating a study of whether certain multifamily residential buildings could safely be designed with a single interior stair, a shift supporters say could reduce construction costs and expand the range of housing projects that can be built on smaller lots.

The order directs an assessment of how modern fire-protection systems—such as sprinklers and contemporary fire-rated construction—perform in buildings that rely on one protected stair for regular egress.

Why the staircase rule matters for housing production

In many typical midrise designs, stairwells and related circulation space can consume a substantial share of a building’s floorplate. Architects and housing researchers say the two-stair requirement often pushes developers toward larger parcels and wider building footprints, because smaller and irregularly shaped sites can become inefficient or financially unworkable once a second stair is added.

State housing officials have identified nearly 5,000 parcels near public transit stops that could be candidates for additional housing. Separate housing research examining transit-proximate, underused parcels has estimated that allowing a single-stair typology under defined conditions could make a significant number of additional units feasible, particularly in projects sometimes described as “missing middle” multifamily—buildings that are larger than triple-deckers but smaller than major high-rise or campus-style developments.

What is being studied: safety, design limits, and implementation

Any change would hinge on safety findings and on the specific conditions attached to single-stair construction. Legislative proposals filed in the 2025–2026 session have outlined a framework for studying single-stair multifamily buildings up to six stories, including producing a draft building-code amendment and identifying mitigation measures for risks that may be unique to single-stair layouts.

Key issues expected to be evaluated include:

• Evacuation and firefighter access when one stair becomes unusable due to smoke or fire conditions.
• Whether design constraints—such as limits on units per floor, floorplate size, and travel distance to the stair—can maintain safety margins.
• The performance of sprinkler systems, fire alarms, compartmentalization, and smoke control in real-world incidents.

Massachusetts officials have framed the effort as an evidence-driven review: expanding housing options while maintaining protections for residents and first responders.

How Massachusetts compares with other jurisdictions

Single-stair residential buildings are permitted in some form in other parts of the U.S., including New York City, and recent policy efforts in several states have also revisited egress requirements for midrise housing. Massachusetts’ current initiative does not itself change the building code; it begins a process that could inform future regulatory updates by the state’s building-code authorities or legislative action.

For now, the outcome will depend on whether the study concludes that narrowly defined single-stair designs can meet public-safety objectives while meaningfully increasing the number and variety of homes that can be built—particularly near transit, where state policy has increasingly focused housing growth.