"Historic resource." A building or structure, including a covered bridge, which:
"Occupied structure." Any structure, vehicle or place adapted for overnight accommodation of persons or for carrying on business therein, whether or not a person is actually present. If a building or structure is divided into separately occupied units, any unit not occupied by the actor is an occupied structure of another.
"Property of another." A building or other property, whether real or personal, in which a person other than the actor has an interest which the actor has no authority to defeat or impair, even though the actor may also have an interest in the building or property.
18 Pa.C.S. § 3301