Building means any structure, including a group of closely situated structural units that are centrally metered or served by a central utility plant, or an eligible portion thereof, the construction of which was completed on or before May 1, 1989, which includes a heating or cooling system, or both.
10 CFR § 455.2
Act, as used in this part, means the Energy Policy and Conservation Act, Public Law 94-163, 89 Stat. 871 (42 U.S.C. 6201, et seq.), as amended by title III of the National Energy Conservation Policy Act, Public Law 95-619, 92 Stat. 3238 (42 U.S.C. 6371), and the State Energy Efficiency Programs Improvement Act of 1990, Public Law 101-440, 104 Stat. 1011.