as placed in service on the most recent date any additional building elected by the taxpayer (with respect to such prior building) was placed in service. (C) Special rule A building— (i) other than the 1st building placed in service as part of a project, and (ii) other than a building which is placed in service during the 12-month period described in subparagraph (A) with respect to a prior building which becomes a qualified middle-income building, shall in no event be treated as a qualified middle-income building unless the project is a qualified middle-income housing project (without regard to such building) on the date such building is placed in service. (D) Projects with more than 1 building must be identified For purposes of this section, a project shall be treated as consisting of only 1 building unless, before the close of the 1st calendar year in the project period (as defined in subsection (h)(1)(F)(ii)), each building which is (or will be) part of such project is identified in such form and manner as the Secretary may provide. (4) Certain rules made applicable Paragraphs (2) (other than subparagraph (A) thereof), (3), and (7) of section 142(d), and section 6652(j), shall apply for purposes of determining whether any project is a qualified middle-income housing project and whether any unit is a middle-income unit