(a) Except as otherwise provided in section 506.5 of this Part, neither a State agency nor other person making a purchase on behalf of a State agency for a building owned or leased in whole by a State agency shall purchase an energy using product, unless such energy using product meets the applicable minimum energy efficiency standard set forth in section 506.4 of this Part.

(b) All building designs or specifications by or for a State agency shall incorporate energy using products which meet the applicable minimum energy efficiency standards set forth in section 506.4 of this Part.

(c) Nothing herein contained shall be construed to prohibit the purchase of an energy using product that is more energy efficient than the applicable minimum energy efficiency standard set forth in section 506.4 of this Part.

(d) A written representation stating the energy efficiency of an energy using product from a manufacturer, retailer, wholesaler, marketer, or other person in the business of selling or providing the energy using product; from a builder, developer, or other contractor who procures, sells, or provides the energy using product; or from a person qualified to determine the efficiency of an energy using product such as a nationally recognized independent testing laboratory or certification program may be relied upon in determining whether the requirements of this Part have been met.