A Washington residential purchase agreement is used when making an offer to purchase real estate. The agreement initiates the negotiation process.A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price. Learn how to fill out the Washington state vacant land purchase and sale agreement in our step-by-step guide! Included Items: All structures and improvements existing on the property as of the date of this agreement, along with all personal property existing on the. Seller agrees to sell to Buyer and Buyer agrees to purchase from Seller the following described real estate in __________________ County, State of Washington. A Washington purchase agreement documents the sale of a piece of real property for a specified financial figure. The completed document will describe the property being sold, purchase price, closing date, and closing costs. Upon the terms and conditions set forth herein, Buyer agrees to buy from Seller, and Seller agrees to sell to Buyer, the real property in Yakima, Yakima County,.