Zoning & Building Rules in Seattle, WA

Seattle has eliminated single-family-only zoning and allows up to 6 units on most residential lots. The city is a national model for density reform, ADU policy, and transit-oriented development. Enter any Seattle address at ReadyPermit.ai for instant zoning analysis including zone code, permitted uses, setbacks, and FAR from 20+ government sources.

ADU eligibility in Seattle depends on your specific zoning designation and lot size. Washington passed HB 1337 (2023) requiring all cities to allow at least 2 ADUs per lot. Seattle has been a national leader in ADU policy for years. Enter your address at ReadyPermit for a property-specific analysis.

Seattle: 4-12 weeks standard, longer for SEPA review. Smaller cities: 2-6 weeks. Washington Growth Management Act requires urban growth boundaries that concentrate development. ReadyPermit estimates permit timelines as part of the Buildability Report for any Seattle address.

The Buildability Score analyzes 142 factors including zoning, flood risk, environmental hazards, and infrastructure for any Seattle address. Scores range 0-100. Enter your address at ReadyPermit for your score.