; (bb) creates disparate review criteria or unequal point access for competing materials; or (cc) increases agency costs of the use. (viii) Internal certification processes The Secretary may by rule allow Federal agencies to develop internal certification processes, using certified professionals, in lieu of certification by certification entities identified under clause (ii). (ix) Privatized military housing With respect to privatized military housing, the Secretary of Defense, after consultation with the Secretary may, through rulemaking, develop alternative certification systems and levels than the systems and levels identified under clause (ii) that achieve an equivalent result in terms of energy savings, sustainable design, and green building performance. (x) Water conservation technologies In addition to any use of water conservation technologies otherwise required by this section, water conservation technologies shall be applied to the extent that the technologies are life-cycle cost-effective. (xi) Effective date (I) Determinations made after december 31, 2017 This subparagraph shall apply to any determination made by a Federal agency after December 31, 2017. (II) Determinations made on or before december 31, 2017 This subparagraph (as in effect on the day before the date of enactment of the Energy and Natural Resources Act of 2017 ) shall apply to any use of a certification system for green commercial and residential buildings by a Federal agency on or before December 31, 2017. ; and (2) by striking subsections (c) and (d) and inserting the following: (c) Periodic review The Secretary shall— (1) once every 5 years, review the Federal building energy standards established under this section