Wash. Rev. Code § 58.28.300
Each lot or parcel of said lands having thereon valuable improvements or buildings ordinarily used as dwellings or for business purposes, not exceeding one-tenth of one acre in area, shall be rated and assessed by the said judge at the sum of one dollar; each lot or parcel of such lands exceeding one-tenth, and not exceeding one-eighth of one acre in area, shall be rated and assessed at the sum of one dollar and fifty cents; each lot or parcel of such lands exceeding in area one-eighth of one acre and not exceeding one-quarter of an acre in area, shall be rated and assessed at the sum of two dollars; and each lot or parcel of such lands exceeding one-quarter of an acre and not exceeding one-half of one acre in area, shall be rated and assessed at the sum of two dollars and fifty cents; and each lot or parcel of land so improved, exceeding one-half acre in area, shall be assessed at the rate of two dollars and fifty cents for each half an acre or fractional part over half an acre; and every lot or parcel of land enclosed, which may not otherwise be improved, claimed by any person, corporation, or association, shall be rated and assessed at the rate of two dollars per acre or fractional part over an acre; and where upon one parcel of land there shall be two or more separate buildings occupied or used ordinarily as dwellings or for business purposes, each such building, for the purposes of this section, shall be considered as standing on a separate lot of land; but the whole of such premises may be conveyed in one deed; which moneys so assessed must constitute a fund from which must be reimbursed or paid the moneys necessary to pay the government of the United States for said townsite lands, and interest thereon, if such moneys have been loaned or advanced for the purpose and expenses of their location, entry and purchase, and cost and expenses attendant upon the making of such survey, plats, publishing and recording, including a reasonable attorney's fee for legal services necessarily performed, and the persons or occupants in such townsite procuring said townsite entry to be made, may employ an attorney to assist them in so doing and to assist such judge in the execution of his or her trust, and he or she shall be allowed by such judge out of said fund a reasonable compensation for his or her services.
RCW 58.28.300