Delaware Code
Subchapter VII. Buyer Property Protection Act
§ 2572. Disclosure of material defects.

(a) Except as excluded by § 2577 of this title hereof, a seller transferring residential real property shall disclose, in writing, to the buyer, agent and subagent, as applicable, all material defects of that property that are known at the time the property is offered for sale or that are known prior to the time of final settlement.
(b) This disclosure shall be made in writing before the seller signs the listing agreement and shall be updated as necessary for any material changes occurring in the property before final settlement.