the term “agency” has the meaning given it in section 551(1) of title 5;

the term “construction” means new construction or substantial rehabilitation of existing structures;

the term “cogeneration facilities” has the same meaning given such term in section 796(18)(A) of title 16;

the term “energy conservation measures” means measures that are applied to a Federal building that improve energy efficiency and are life cycle cost effective and that involve energy conservation, cogeneration facilities, renewable energy sources, improvements in operations and maintenance efficiencies, retrofit activities, or energy consuming devices and required support structures;