The TREC unimproved property contract is one of the most important contract forms in Texas. But do you know when to use it?A land purchase contract outlines a transaction between a seller who agrees to sell raw land to a buyer for an agreed-upon sales price. In this guide, we're taking an in-depth look at a Texas Purchase Contract, what each section means, and what you should look out for. PARTIES: The parties to this contract are. (Seller) and. (Buyer). Your agreement should specific the date on which the seller will give you a deed to the land and you will complete your payment. A Texas land contract establishes terms binding the parties in the sale of vacant land.