The following definitions apply to this subchapter:

(1) "AFUE" means annual fuel utilization efficiency rating for furnaces and boilers expressed as the ratio of energy output to energy input.

(2) "Building" means an enclosed structure with external walls and a roof. This includes single units within multi-unit complexes such as apartment complexes, condominiums and commercial complexes.

(3) "Customer" is defined as a retail purchaser or distribution service provider.

(4) "Energy factor" is the efficiency rating for water heaters. A higher percentage indicates higher efficiency.

(5) "ENERGY STAR" is a program of the U.S. Environmental Protection Agency, which identifies high efficiency products and equipment.

(6) "GAMA" means Gas Appliance Manufacturers Association, which is an independent agency for rating space and water heating devices.

(7) "Heat recovery ventilator" is a device or system designed and installed to provide balanced fresh air ventilation for homes and to transfer energy from the outgoing air stream to the incoming air stream.

(8) "HSPF" means heating season performance factor, which is a measure of the heating efficiency of a heat pump system expressed as a ratio of Btu per watt-hour.

(9) "HVI" means Home Ventilating Institute, which is a rating agency for home ventilation products.

(10) "IECC" means the 2003 International Energy Conservation Code, which is the current energy code version adopted by the state of Montana and enforced statewide.

(11) "National Fenestration Rating Council" (NFRC) means the independent agency that rates windows, doors and skylights.

(12) "New construction" means construction of, or additions to, buildings, living areas, or attached garages that comply with the established standards of new construction as determined by the building code statutes in Title 50, MCA.