Washington Land Contract Template. A Washington land contract is a formal sale agreement between two parties transferring ownership of vacant real estate.Learn how to fill out the Washington state vacant land purchase and sale agreement in our step-by-step guide! NOTE: Fill in the date in the following two lines only if there is an early cash out date on the assumed obligation. Discounted set of the following forms, which are required for a standard residential property sale. A Washington residential purchase agreement is used when making an offer to purchase real estate. The agreement initiates the negotiation process. The completed document will describe the property being sold, purchase price, closing date, and closing costs. Requires legal size paper (8.5 x 14") to print. A Washington purchase agreement documents the sale of a piece of real property for a specified financial figure.