The National Fire Protection Association (NFPA) released “One Stair, Two Perspectives: Single Exit Stair Symposium,” a report summarizing key discussions and findings from a recent symposium addressing concerning efforts by legislative bodies in the U.S. and Canada to increase the allowable height of single exit stair apartment buildings from three or four stories to six.

The International Code Council and NFPA codes currently allow single exit stair buildings under specific conditions for new apartment buildings up to three and four stories, respectively; however, the symposium focused on a recent legislative trend, falling outside the traditional codes and standards development process, to increase the allowable height to six stories for such buildings.

The International Single Exit Stair Symposium held September 11–12, 2024, gathered fire protection experts, code authorities, building officials, and other stakeholders from the United States, Canada, the United Kingdom, and Australia. The goal of the symposium was to bring together proponents and opponents for a detailed discussion of the issue, to identify concerns with proposed changes, and identify knowledge gaps.

“The purpose of this report is to provide a fire and life safety perspective on single exit stair proposals,” said Christian Dubay, NFPA vice president and chief engineer. "There are many safety factors to consider before approving the construction of single-exit buildings beyond current limits, and what works in one jurisdiction may not be appropriate elsewhere. The report chronicles the current status, concerns, and gaps as a critical baseline for how to take the next steps on this critical issue.”

While acknowledging the pressing need to provide affordable housing throughout the world, symposium participants and the resulting report emphasize the need for safety and highlight the risks of enacting single exit allowances through legislative action. As noted in the report’s executive summary, evaluating changes to the height of an apartment building served by a single exit stair “belongs in a time-tested, balanced, consensus-based standards development process… When this process is substituted by uninformed legislative action, special interests, or misguided local policy decisions, there is great risk to the protection and safety of people and property.”

Key concerns highlighted

The report, “One Stair, Two Perspectives: Single Exit Stair Symposium,” outlines several crucial safety concerns related to the proposed increase in allowable height for single exit stair apartment buildings. Key concerns include:

• Single Point of Egress Failure: A single exit stair creates a critical point of vulnerability. If the stair is compromised by smoke or fire, occupants may be left without a safe evacuation route, putting lives at risk.
• Types of Allowable Construction: The types of construction permitted for single exit stair buildings may lack sufficient fire resistance, necessitating a careful review of construction type to ensure occupant safety.
• Impact on Emergency Response Operations: Closer examination of this concern will require an understanding of what the current baseline is for emergency response, operations, and capabilities when responding to emergencies in single stair residential buildings.
• Occupants Exiting while First Responders are Entering: Counterflow between evacuating occupants and incoming responders can hinder rescue operations and increase the risk of smoke and fire spreading.
• Post-Occupancy Hazards: Human behavior can introduce new risks post-occupancy, such as obstructed exits and poor inspection, testing, and maintenance practices that may compromise the safety of a single egress point.

There was general consensus among attendees that additional data collection and research are needed. The report highlights six priority areas for further research to ensure that a comprehensive understanding of single exit stair safety informs future policy and code actions:

1. Impact on Firefighter Operations: Analyzing how a single exit impacts firefighters’ ability to perform rescue operations efficiently, especially during counterflow with evacuating occupants, and evaluating the impact of reduced stair access on firefighting tactics.
2. Need for Detailed Comparisons and Analysis: Answering concerns about increasing allowable heights of apartment buildings with single exits requires a clear understanding of what is currently allowed. A code analysis comparing four-story buildings with one and two exits with six-story buildings with two exits would be valuable.
3. More Detailed and Consistent Data: Current fire data cannot quantify the impact of having only a single exit. Fire modeling may be needed to address evacuation concerns. Data on the cost, maintenance, and reliability of smoke control systems is also needed.
4. Impact of Human Characteristics on Fire Risk: Examining how the change in specific demographic factors, including age, mobility, and physical ability levels of residents and how they affect evacuation success in single-exit buildings is necessary.
5. Stairway Construction Considerations: Assessing how different stairway construction materials and configurations, including stair and landing widths, impact fire and life safety including safe egress from the building during emergencies.
6. Impact of Emerging Technologies on Egress Safety: Investigating how the fire risks associated with new technologies, such as lithium-ion batteries, impact safety in single exit buildings.

Next steps: New research to address knowledge gaps

NFPA will sponsor a research initiative through the Fire Protection Research Foundation (FPRF) to address critical knowledge gaps. This research will focus on a comprehensive code analysis and egress modeling study to assess the safety implications of single exit arrangements in six-story buildings. Findings from this research will contribute to the consensus-based codes and standards process, guiding future decisions on potential single exit stair allowances.