Detailed guide by Seattle Public Library on how to research area buildings, including many of the resources in this guide and more. Includes workbooks, checklists and other tools, making this publication a great starting point for your research.
The Puget Sound Branch of the Washington State Archives holds pre-1974 records from the King County Assessor's Office as well as other relevant materials. These records include photographs of houses and building improvements from approximately 1937 to 1971. In addition, the archives houses property record cards and tax assessment rolls.
The King County Assessor's Office offers a variety of online resources for property assessment, including sales and tax records as well as parcel maps. Use the Assessor's Office for current and/or post-1973 house information.