16 U.S.C. § 410x–2: “Residential property” defined

As used in this subchapter, the term “residential property” means a single-family dwelling, the construction of which began before July 1, 1991, together with such land on which the dwelling and appurtenant buildings are located as is in the same ownership as such dwelling and as the Secretary designates as reasonably necessary for the owner’s continued use and occupancy of the dwelling.