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Seattle’s 'Single-Stair' Revolution: Rewriting the Rules for Urban Real Estate

Fast Company March 22, 2026

Real estate investors and urban developers should take note of Seattle’s building code reform, which unlocks massive value in 'unbuildable' small lots by permitting single-stairwell designs. This shift is sparking a national movement to increase urban density and ROI by removing the prohibitive costs of traditional multi-exit requirements.

Key Intelligence

  • Seattle is proving that changing a single line of fire code—allowing single-stairwell buildings—can turn 'forgotten' small lots into profitable mid-rise housing.
  • The reform ends a long-standing deadlock between fire officials and urbanists, prioritizing land-use efficiency over redundant egress requirements for smaller footprints.
  • Apparently, traditional US codes often mandate two staircases for buildings as short as three stories, a rule that makes development on narrow urban lots financially impossible.
  • The 'Point Access Block' design is standard in Europe and Asia; its adoption in the US could fundamentally change the economics of urban infill projects.
  • Did you hear that California and other states are now fast-tracking similar reforms to solve the housing supply crunch and lower construction costs?
  • For developers, this represents a new asset class: high-density, small-footprint residential projects in premium core urban markets.
  • While fire safety remains the primary concern, modern sprinkler systems and fire-resistant materials are making the case for single-stair designs much stronger.