Request for Input on AB 835 Single Stair Initiative

Deputy Fire Chief/Fire Marshal James Dobson of the San Jose Fire Department is seeking feedback to further his research on firefighter operations, fire modeling for evacuation safety, and the effectiveness of smoke control systems. We encourage CalChiefs members to provide input on the following:

• How would a single-stair design impact fireground operations?
• Are there specific operational concerns based on your department’s capabilities
• What additional protections or code changes should be considered to mitigate risks?
• Do you have examples in your jurisdictions where a single stair affected evacuation and operational capabilities?

Please provide your responses HERE. 

Read below for more details on the initiative and key findings so far!

Deputy Chief Dobson is representing CalChiefs on the AB 835 Single Stair Task Group and would like to provide information and solicit responses from CalChiefs members to share with the workgroup regarding the single-stair initiative.

For context, AB 835 requires the Office of the State Fire Marshal to develop recommendations regarding single-stair emergency exits for multi-floor occupancies. During the initial meeting, a motion was advanced to limit discussion to buildings between three stories and 75 feet tall (per the California Fire Code’s high-rise definition). While the idea of a single stair for exiting and fire operations may elicit strong reactions, Deputy Chief Dobson’s objective is to gather data-driven responses regarding safety concerns and the potential impact on operational effectiveness.

Key Findings So Far:

Arguments in Favor of Single-Stair Designs

Proponents, primarily architects and politicians, cite:

• Increased flexibility for architectural design

• Sprinklers contain the fire to the room of origin

• Maximized occupiable floor space in urban areas with limited square footage
• Common international use (e.g., South Korea, Germany, Switzerland—countries with stronger fire safety outcomes than the U.S.)
• Differences in construction standards (Europe favors noncombustible materials)
• Lower housing costs, especially amid the housing crisis

Concerns from Fire Officials & Code Officials

Fire departments, fire marshals, and code officials have expressed concerns due to:

• Operational flexibility: Two stairwells allow one to serve as an escape route while the other supports firefighting operations.

• Seismically active state:  While sprinklers effectively save lives, they may be inactive during a natural disaster due to damage of water supply sources.

• Redundant exits: In emergencies (e.g., earthquakes), a second stairwell provides a backup if one becomes compromised.
• Egress challenges: Evacuation models assume clear stairways, but a shared firefighter/occupant stairwell could slow evacuation and spread smoke.
• International code differences: Some countries count balconies/windows as secondary egress points—this is not the case under California codes.
• Fire department considerations: Germany limits single-stair buildings to the height accessible by local fire department equipment.
• Unanswered operational questions: Should fire departments delay entry until evacuation is complete? Otherwise, they risk filling the single stairwell with smoke.

Case Study: Seattle’s Single-Stair Allowance (Up to 6 Stories)

Seattle allows single-stair buildings up to six stories with additional fire protection requirements, such as:

• Sprinklered and pressurized stairwells
• 20-foot travel distances from apartment entrances to stairwells
• Hydrants at every corner, well-funded fire services, and extensive aerial ladder coverage

Seattle code officials originally opposed the policy, fearing that it wouldn’t be viable for smaller or less-funded fire departments. While Seattle’s fire setup makes it feasible, it may not be replicable statewide or in other jurisdictions.

Overall Key Concerns

• Single point of egress failure
• Construction type limitations
• Fire department response capabilities and how they would need to adapt

• Counterflow of evacuees and firefighters, slowing egress and increasing smoke spread

• System redundancy

• Post-occupancy hazards (e.g., blocked exits, lack of inspections, maintenance failures)

Research & Studies Underway

Current studies are examining the fire safety implications of single-stair buildings:

• Minnesota Study (Target Completion: Oct 2025): Evaluating fire loss history, fire department operations, and stakeholder input
• California Study (Target Completion: Jan 2026): Establishing mandatory building standards for single-exit residential buildings over three stories
• New York Study (Target Completion: July 2026): Analyzing design feasibility, hazards, alternatives, and cost savings

A Virginia Advisory Study has already been completed. It concludes that single-stair configurations negatively impact rescue and suppression efforts. The study recommends additional protections, such as improved construction standards, closer exterior access for firefighters, wider stairwells, and enhanced smoke control systems.

Resources & Additional Information

• NFPA Report on Single-Exit Stair Apartment Buildings
• NFPA Journal Article on the Debate