Del. Code tit. 17 § 139
After the Department has determined upon the road or roads which shall be maintained as state highways, it shall cause notice thereof to be sent by mail, a record of which shall be preserved, to all persons owning property abutting upon or contiguous to such road or roads, and any such owner or the legal representative of any such owner, who after such notice has been given shall construct any building within 60 feet of the center line of any such road, shall be allowed no compensation for such building, upon the condemnation thereof, or the land upon which it is situated, unless such owner shall serve written notice upon the Department within 3 months from the time that the owner receives such notice that the owner claims damages.
17 Del. C. § 139