housing units (1) In general Subsection (a)(1) shall be applied by substituting 25 percent for 15 percent with respect to so much of the qualified rehabilitation expenditures (determined without regard to subsection (c)(2)(E)) with respect to any qualified rehabilitated building as are properly allocable to residential units which are— (A) rent-restricted (within the meaning of section 42(g)(2)), and (B) occupied by individuals whose income is 100 percent or less of area median gross income (within the meaning of section 42(g)(1)). (2) Failure to maintain rent-restriction subject to recapture In the case of any failure to maintain any residential unit taken into account under paragraph (1) as a residential unit described in such paragraph during the recapture period, section 50(a) shall apply as though the qualified rehabilitated building ceased to be investment credit property except that the recapture period and recapture percentage shall be determined under paragraph (3) and in determining the increase in tax under such section in lieu of reducing the credit determined under this section to zero such credit shall be determined without regard to paragraph (1). The application of section 50(a) with respect to a building as described in this paragraph shall not prevent the reapplication of such section to such building if such building is disposed of or otherwise ceases to be investment credit property and the tax imposed under such section by reason of such reapplication shall be reduced by the tax previously imposed as described in this paragraph. (3) Recapture period