Single-family-only zoning has officially ended in the City of Seattle. On May 27, 2025, the Seattle City Council passed CB 120969 to comply with RCW 36.70A.635, which requires adoption of development regulations allowing for "middle housing"—including multi-unit complexes, stacked flat apartments, townhouses, and cottage houses—in all of Seattle's residential zones. Under the new ordinance, which went into effect June 30, 2025, all of Seattle's residential areas now allow at least four units per lot, and up to six units per lot near transit or that include two affordable housing units. Additionally, the ordinance removes residential parking requirements for middle housing near major transit stops and allows slightly larger building footprints and heights than before.
This ordinance is only a temporary measure intended to meet the state's compliance deadline. It will expire in one year and will be replaced by permanent regulation tied to Seattle's Comprehensive Plan update. That update is expected to include further changes such as stronger affordable housing incentives and revised building design standards.
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