This is a basic tutorial on writing up an offer for a WA single family home only. Understanding Washington contracts real estate is crucial for anyone looking to buy or sell property in the Evergreen State.A Washington purchase agreement documents the sale of a piece of real property for a specified financial figure. Washington requires those selling FSBO to fill out and file many documents and forms. Find out key issues involved with selling a house in Washington State. Ensure you know the legal requirements and disclosures of a Washington real estate purchase agreement. Fill in our template to create your agreement. Cons of a sales contingency for buyers. Ready to Draw Up Your Washington State FSBO Contract? Stating all contingencies the parties must complete before the sale, like a home inspection, financing, or repairs.