Single-Stair Code Alternate
Effective March 2026, the City of Vancouver has adopted Seattle’s single-stair building code option as an approved alternate compliance path for new residential development. The interim policy allows architects and builders to begin using the design approach while broader code work continues at the state level.
Single-stair building design allows certain mid-rise residential buildings to be served by one stair rather than two, when enhanced life-safety standards are met. The approach is increasingly used to support efficient building layouts and expand housing options.
By recognizing Seattle’s established code framework as an approved alternate, Vancouver is enabling local design teams to move forward with projects that use the model while maintaining safety standards. The policy provides a clear pathway for architects and builders interested in incorporating single-stair configurations in qualifying projects.
City staff will continue coordinating with state agencies, industry professionals, and regional partners as the statewide code development advances.
For additional information, project teams are encouraged to contact our Plan Review Team or call 360-487-7828
General Policy
Not more than 5 stories of Group R-2 occupancy are permitted to be served by a single exit under the following conditions:
Building Size
- The building has not more than six stories above grade plane.
- There shall be no more than four dwelling units on any floor.
Building Use
- The building does not contain a boarding house.
- Other occupancies are permitted in the same building provided they comply with all the requirements of this code.
- Other occupancies shall not communicate with the Group R occupancy portion of the building or with the single-exit stairway.
- Exception: parking garages and occupied roofs accessory to the Group R occupancy are permitted to communicate with the exit stairway.
Fire Protection
- The building shall be of not less than one hour fire-resistive construction and shall also be equipped throughout with an automatic sprinkler system in accordance with subsection 903.3.1.1 (NFPA 13 sprinkler protection).
Exiting and Stairways
- There shall be no more than two single exit stairway conditions on the same property.
- An exterior stairway or interior exit stairway shall be provided.
- The interior exit stairway, including any related exit passageway, shall be pressurized in accordance with subsection 909.20
- Doors in the stairway shall swing into the interior exit stairway regardless of the occupant load served, provided that doors from the interior exit stairway to the building exterior are permitted to swing in the direction of exit travel.
- A corridor shall separate each dwelling unit entry/exit door from the door to an interior exit stairway, including any related exit passageway, on each floor.
- Dwelling unit doors shall not open directly into an interior exit stairway.
- Dwelling unit doors are permitted to open directly into an exterior stairway.
- There shall be no more than 20 feet (6096 mm) of travel to the exit stairway from the entry/exit door of any dwelling unit.
- Travel distance measured in accordance with section 1017 shall not exceed 125 feet (38100 mm).
- The exit shall not terminate in an egress court where the court depth exceeds the court width unless it is possible to exit in either direction to the public way.
- The exit serving the Group R occupancy shall not discharge through any other occupancy, including an accessory parking garage.
- There shall be no openings within 10 feet (3048 mm) of unprotected openings into the stairway other than required exit doors having a one-hour fire-resistance rating.
Elevators
- Elevators shall be pressurized in accordance with section 909.21 or shall open into elevator lobbies that comply with section 713.14.
