King County, WA Historic Preservation: Historic-Cultural Monuments (2026)
Key Facts
- Permit required
- Certificate of appropriateness before alteration
- Coverage
- Unincorporated King County only
- Penalty
- Up to $500 per day
- Age threshold
- Resource must be 40+ years old
- Decision-maker
- County Landmarks Commission
Summary
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.
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 requires a building or other permit. The requirements of this section shall not apply to any historic resource located within incorporated cities or towns in King County, except as provided by applicable interlocal agreement.
B. Ordinary repairs and maintenance which do not alter the appearance of a significant feature and do not utilize substitute materials do not require a certificate of appropriateness. Repairs to or replacement of utility systems do not require a certificate of appropriateness provided that such work does not alter an exterior significant feature.
C. There shall be three types of certificates of appropriateness, as follows:
1. Type I, for restorations and major repairs which utilize in-kind materials.
2. Type II, for alterations in appearance, replacement of historic materials and new construction.
3. Type III, for demolition, moving and excavation of archaeological sites.
Full Breakdown
King County's Landmarks Commission designates buildings, sites, structures, districts and objects at least 40 years old as county landmarks under K.C.C. chapter 20.62. Once a resource is designated, or once it gets a preliminary determination of significance, the owner must obtain a certificate of appropriateness before altering, replacing materials on, or demolishing any significant feature named in the designation report, even for work that needs no separate building permit. Ordinary repairs and maintenance that don't change a feature's appearance are exempt. The rule applies only in unincorporated King County; Seattle, Bellevue, Kent and the county's roughly 27 other incorporated cities run their own landmark programs unless a specific interlocal agreement extends county review into their limits.
Violations & Fines
Altering a landmark's significant features without a certificate of appropriateness draws a civil penalty of up to $500 per day, with each day of noncompliance a separate violation.
Frequently Asked Questions
Does this rule cover landmarks in Seattle?
What triggers the certificate of appropriateness requirement?
Sources & Official References
Other rules in King County
Compare King County to another location·View the Washington historic preservation overview
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