Wash. Rev. Code § 64.55.060
Upon completion of an inspection required by this chapter, the qualified inspector shall prepare and submit to the appropriate building department a signed letter certifying that the building enclosure has been inspected during the course of construction or rehabilitative construction and that it has been constructed or reconstructed in substantial compliance with the building enclosure design documents, as updated pursuant to RCW 64.55.020. The building department shall not issue a final certificate of occupancy or other equivalent final acceptance until the letter required by this section has been submitted. The building department is not charged with and has no responsibility for determining whether the building enclosure inspection is adequate or appropriate to satisfy the requirements of this chapter.
RCW 64.55.060