A Washington residential purchase agreement is used when making an offer to purchase real estate. The agreement initiates the negotiation process.The first step is the details. Scroll down to the bottom of this section to define the purchase price, offer date, expiration date, and closing date. Learn the fundamentals of drafting an offer on a residential property in Washington State. Any personal property included in the sale shall be included in the fulfillment deed. 9. An Offer to Purchase Real Estate sets out the terms of a proposed real estate deal. Create yours now with our free form. Learn the fundamentals of drafting an offer on a vacant land property in Washington State. Ensure you know the legal requirements and disclosures of a Washington real estate purchase agreement.