“Washington state continues to lead the pack with measures to lower the cost of homebuilding and make it easier to build more homes, in all shapes and sizes, in more places. The state reformed building codes to allow single-stair apartments in 2023, to extend residential code to middle housing in 2024, and in 2026, to legalize smaller elevators, as well as—the focus of this article—scissor stairs.

Scissor stairs are a design feature common in other countries but rare in most US cities. They help save more of a building’s interior square footage for homes, while still providing two fire-safe staircases for residents and emergency responders. What’s more, scissor stairs make it possible to design for more light and cross-breeze in every apartment, plus accommodate narrow or oddly shaped lots for more infill opportunities.”

From Sightline Institute.