Wash. Rev. Code § 65.20.050
The department shall approve the application for elimination of the title when all requirements listed in RCW 65.20.040 have been satisfied and the registered and legal owners of the manufactured home have consented to the elimination of the title. After approval, the department shall have the approved application recorded in the county or counties in which the land is located and on which the manufactured home is affixed.
The county auditor shall record the approved application, and any other form prescribed by the department, in the county real property records. The manufactured home shall then be treated as real property as if it were a site-built structure. Removal of the manufactured home from the land is prohibited unless the procedures set forth in RCW 65.20.070 are complied with.
The department shall cancel the title after verification that the county auditor has recorded the appropriate documents, and the department shall maintain a record of each manufactured home title eliminated under this chapter by vehicle identification number. The title is deemed eliminated on the date the appropriate documents are recorded by the county auditor.
RCW 65.20.050