Historic Preservation in King County, WA (2026)

1 county-level rule, plus city-specific rules for 6 cities in King County, Washington.

Verified from official government sources

Note: These county rules apply to unincorporated areas of King County. If you live within an incorporated city, that city's own rules apply: see the city list below.

Historic-Cultural Monuments

Altering a significant feature of a King County-designated landmark requires a certificate of appropriateness from the county's Landmarks Commission before work begins, whether or not a building permit is also required.

King County Landmark Alteration Permit Rules

Significant Restrictions

King County Code § 20.62.080

a certificate of appropriateness must be obtained from the commission before any alterations may be made to the significant features of the landmark identified in the preliminary determination report or thereafter in the designation report. The designation report shall supersede the preliminary determination report. This requirement shall apply whether or not the proposed alteration also requ...

Full ordinance details →Official source ↗