Beta — site is under development, information may contain errors. Read disclaimer

Washington Zoning & Land Use Guide

Last updated: Verified:

Comprehensive guide to Washington zoning laws, building codes, and land use regulations.

Key Facts

  • Building Code: WA State Building Code (based on 2021 IBC)
  • State ADU Law: Yes — ADU-friendly
  • ADU Details: HB 1337 (2023) requires cities and counties planning under the GMA to allow at least two ADUs per single-family lot.

Cities in Washington