The Seattle City Council has unanimously passed new interim zoning rules that dramatically reshape what can be built in residential neighborhoods across the city. The legislation, passed this week, brings Seattle into compliance with recent state mandates to allow more ‘middle housing’ and will remain in effect for one year while permanent rules are developed.

Under the new rules, nearly all residential lots citywide are now eligible for up to four housing units by default. That number rises to six units on lots within a quarter-mile of major transit stops, or when at least two of the units are income-restricted affordable housing. This ends Seattle’s long-standing single-family zoning framework and replaces it with more flexible density allowances aimed at addressing the city’s housing shortage.

Key changes include:

• Lot coverage is limited to 50% of the lot area, meaning no more than half of a property may be covered by buildings.
• Floor area ratio (FAR) standards increased from the previous 0.5 limit for single-family lots: single-unit lots may now build up to 0.6 times the lot size in floor area; two-unit lots may build up to 0.8 FAR; three-unit lots may build up to 1.0 FAR; and lots with four or more units may build up to 1.2 FAR.
• Maximum building height increased to 32 feet for most neighborhood residential lots.
• Front and rear yard setbacks reduced, generally to 10 or 15 feet depending on the number of units.
• New parking minimums largely eliminated for middle housing within half a mile of frequent transit, in line with state mandates.
• Design review standards modified to ensure they are ‘clear and objective,’ limiting subjective aesthetic reviews that could delay projects.

The legislation was necessary to meet deadlines set by multiple state laws, including House Bill 1110, Senate Bill 6015, and others. If Seattle had not acted by June 30, 2025, the state’s model code would have automatically applied.

This interim bill is not the final word. It functions as a stopgap while the city finalizes its updated Comprehensive Plan, expected for adoption in October 2025. That plan will set Seattle’s long-term growth strategy through 2044 and could further refine how middle housing fits into Seattle’s evolving neighborhoods.