︎

Single Stair Housing Studies

_
Socially rich, straw-filled single-stair housing
Primary Projects + RUKA Design
While designing Split Switchback Housing, we tested a few variants to see if it could serve as a prototypical solution for Denver. In 2025, we used the National Single Stair Housing Competition as an opportunity to test the approach on three sites with wildly different dimensions and conditions. 

Denver’s Split Switchback Housing had both street & alley access and was large enough to allow for setbacks on all sides. Across the new sites we tested: zero-lot-line conditions, single-sided fire truck access, on-site fire lanes, and alternative unit layouts.



Logic & Constraints

Denver Austin Portland San Francisco


Street Presence

Sun shading balconies in Austin

Corner balconies and fire lane as lawn in Portland

Alternating balconies in SF



Plans

Austin First Floor Austin Third Floor Austin Sixth Floor
Portland First Floor Portland Third Floor Portland Sixth Floor
SF First Floor SF Third Floor SF Sixth Floor




One Stair, Several Ways

An inset stair in Austin



The peekaboo stair abuts balconies in Portland



Stair as succulent lightwell in SF





Rooftop Vibes

Each roof has space for gardening....

shared meals, and....
laundry




Bonus Content

The fire lane in Portland doubles as a social zone Innies and outies form shared or private balconies in SF Light colors and reflective surface bounce light on a deep site in SF



Stats

  • 6-stories
  • 16 units:
        12 studios
        4 three-beds
  • Amenities: Covered Outdoor Cafe Seating, Community Room, Bike Room, Communal Living Room, Shared Laundry, Rooftop Deck, Social Stair

Services

  • Architectural Design
  • Zoning Analysis
  • Interior Design

Tags

Attainable, Communal, Housing, Carbon Smart, Prefab, Missing Middle, Point Access Block



Related Work