Senate committee hears update on single‑stair multifamily code change

Senate Committee on Housing and Development Chair Pham on May 19 opened an informational briefing on proposed building‑code changes to allow some multistory residential buildings to use a single stair as an approved means of egress.

Architect Michael Eliasson, of LaunchLab in Seattle, told the committee that single‑stair, point‑access buildings are common in many other countries and that allowing single‑stair designs can enable smaller, thinner buildings with more daylight, cross‑ventilation and family‑sized units compared with double‑loaded‑corridor apartments. “Seattle actually started allowing these in the in the late seventies…so we’ve had it for almost 50 years,” Eliasson said, describing that city’s experience with six‑floor single‑stair buildings.

Alana Cox, administrator of the Building Codes Division (BCD) at the Oregon Department of Consumer and Business Services (DCBS), told the committee the state is working to incorporate a single‑stair pathway into Oregon’s code. “Spoiler alert, we are doing it,” Cox said, describing the statutory direction from House Bill 33‑95 (2023) and the division’s use of the 2027 International Building Code package as a starting point. Cox said the Building Code Structures Board approved the single‑stair code package at a recent meeting and that BCD will notice the full Oregon Structural Specialty Code (OSSC) package for rulemaking, with an anticipated adoption date of Oct. 1, 2025. Local governments would retain the option to adopt the change based on their assessment of local firefighting capacity.

Committee members pressed on safety and local firefighting capacity. Cox noted the statewide code must account for “regional variation in firefighting capacity and equipment,” and explained the three‑year code cycle and rulemaking steps that follow board approval. Eliasson and Cox referenced research and safety studies discussed at the national level; Eliasson said some analyses have found single‑stair buildings “as safe or safer” than comparable double‑egress buildings when modern safety systems are used.

The committee did not take a formal vote during the informational meeting. Cox said the approved package contains additional safety measures intended to mitigate the risks of a single stair and that the code will be reviewed on the regular three‑year cycle. She said the package as currently proposed allows single‑stair designs through four stories above grade in Oregon’s starting proposal, while noting other jurisdictions such as the City of Seattle have allowed up to six stories under local authority.

Committee Chair Pham closed the informational portion and moved on to the next agenda item.

Why it matters: Allowing single‑stair multifamily buildings is intended to reduce construction costs, encourage a different building form that can support more family‑sized and lower‑impact units, and possibly improve embodied carbon outcomes, while raising questions about firefighting capacity and occupant safety that will continue to shape local adoption.