Wash. Rev. Code § 58.17.210
No building permit, septic tank permit, or other development permit, shall be issued for any lot, tract, or parcel of land divided in violation of this chapter or local regulations adopted pursuant thereto unless the authority authorized to issue such permit finds that the public interest will not be adversely affected thereby. The prohibition contained in this section shall not apply to an innocent purchaser for value without actual notice. All purchasers' or transferees' property shall comply with provisions of this chapter and each purchaser or transferee may recover his or her damages from any person, firm, corporation, or agent selling or transferring land in violation of this chapter or local regulations adopted pursuant thereto, including any amount reasonably spent as a result of inability to obtain any development permit and spent to conform to the requirements of this chapter as well as cost of investigation, suit, and reasonable attorneys' fees occasioned thereby. Such purchaser or transferee may as an alternative to conforming his or her property to these requirements, rescind the sale or transfer and recover costs of investigation, suit, and reasonable attorneys' fees occasioned thereby.
RCW 58.17.210