; (ii) Existing structures For existing structures, a reduction in energy consumption from the previous level of consumption for the structure, as determined in accordance with energy audits performed both before and after any rehabilitation or improvements undertaken to reduce such consumption by at least 30 percent or achievement of ENERGY STAR certification. (B) Nonresidential structures With respect to nonresidential structures, such energy efficiency and conservation requirements, standards, checklists, or rating systems for nonresidential structures as the Secretary shall identify and adopt by regulation, as may be necessary, for purposes of this paragraph. (4) Green building standards The green building standards under this paragraph are the most recent adopted versions of the following: (A) The national Green Communities criteria checklist for residential construction that provides criteria for the design, development, and operation of affordable housing, as such checklist or successor checklist is in effect for purposes of this section pursuant to paragraph (7). (B) The LEED for New Construction rating system, the LEED for Homes rating system, the LEED for Core and Shell rating system, as applicable, as such systems or successor systems are in effect for purposes of this section pursuant to paragraph (7). (C) The Green Globes assessment and rating system of the Green Buildings Initiative. (D) For manufactured housing, energy star rating with respect to fixtures, appliances, and equipment in such housing, as such standard or successor standard is in effect for purposes of this section pursuant to paragraph (7). (E) The National Green Building Standard. (F) Any other proven requirements, standards, checklists, or rating systems for green building or sustainability as the Secretary may identify and adopt by regulation, as may be necessary for purposes of this paragraph, except that the Secretary shall make a determination regarding whether to adopt and apply any such requirements, standards, checklist, or