Concerning historic landmark designations.

SB 5554 requires cities in Washington to adopt or update local regulations for residential and mixed-use properties within one year to align with new historic landmark designation rules. The bill prohibits cities from designating properties under 40 years old as historic landmarks and mandates written owner consent for any designation that restricts property use, alteration, or demolition - without consent, such designations are invalid. Exceptions apply only for properties within existing historic districts established under local ordinances. The law overrides conflicting local rules and applies to all cities, including code cities, with specific provisions for implementation timelines.