energy efficient building retrofit property
(3) Energy efficient building retrofit property For purposes of this subsection, the term “energy efficient building retrofit property” means property— (A) with respect to which depreciation (or amortization in lieu of depreciation) is allowable, (B) which is installed on or in any qualified building, (C) which is installed as part of— (i) the interior lighting systems, (ii) the heating, cooling, ventilation, and hot water systems, or (iii) the building envelope, and (D) which is certified in accordance with paragraph (2)(B) as meeting the requirements of subparagraphs (B) and (C).