Appeal 33557

OSCC 403.5.1

OSSC 403.5.1 specifies that in high-rise buildings, interior exit stairways must be located remotely from each other to ensure redundancy. This code section expressly identifies that scissor stairs shall be counted only as one interior exit stairway.

This code appeal seeks authorization to use a single scissor stair configuration to satisfy the exit requirements of IBC 1006.3 and OSSC 403.5.1 in a high-rise building, providing two egress paths within a limited footprint while ensuring compliance with safety and functional standards.

We are developing an affordable housing project in Portland that maximizes density by leveraging the city’s new Floor Area Ratio (FAR) allowances, designed to encourage high-density, affordable construction. Our building, with a footprint of approximately 50x80 feet, achieves this increased density with a carefully designed scissor stair—the only viable solution to provide both required egress paths within the compact space.

This scissor stair is housed within a concrete, fire-rated enclosure that meets or exceeds all fire resistance standards. The building’s symmetrical design calls for four units on either side of the stairway on each floor. Units on each side must travel the same distance to reach the stairway. This approach to egress ensures safe and efficient evacuation and enhances fire safety through both structural and design considerations.

The alternate scissor stair design is required due to the compact footprint of our affordable housing project, which measures approximately 50x80 feet. This dense configuration, enabled by Portland’s updated Floor Area Ratio (FAR) allowances, supports the city’s goals for increased affordable housing availability. Given the limited building area, it is infeasible to incorporate two separate stair shafts without significantly compromising the number of housing units we can provide.

The proposed scissor stair configuration is housed within a concrete, fire-rated enclosure, meeting all required fire resistance standards. This enclosed scissor stair will provide two distinct egress paths, effectively satisfying egress needs while ensuring equivalent levels of life safety and fire protection. The concrete enclosure guarantees that both paths remain protected during an emergency, and each stair flight functions independently within the shared shaft.