If someone sold your property without your knowledge, you need to act quickly. Selling a house without a realtor involves preparing prelisting, listing, disclosure, negotiation, and closing paperwork.Legal help can be beneficial. Illinois law requires sellers to disclose known defects, radon levels, and septic system conditions when selling asis. In order to sell an Illinois house in 'as is' condition, sellers must fill out a property disclosure. You must disclose any issues with your house. Illinois law requires you, as a home seller, to tell a prospective buyer, in writing, about any material defects on the property that you actually know about. For transfers of a beneficial interest of a land trust, complete the form substituting the words "assignor" for "seller" and. "assignee" for "buyer. Selling your house without a realtor, or "For Sale By Owner" (FSBO), can be a cost-effective option for Illinois homeowners.