; certification system and level for green buildings. Sec. 423. Enhanced energy efficiency underwriting. TITLE V—Miscellaneous Sec. 501. Budgetary effects. Sec. 502. Advance appropriations required. 2. Definition of Secretary In this Act, the term Secretary means the Secretary of Energy. I Buildings A Building energy codes 101. Greater energy efficiency in building codes (a) Definitions Section 303 of the Energy Conservation and Production Act ( 42 U.S.C. 6832 ) is amended— (1) by striking paragraph (14) and inserting the following: (14) Model building energy code The term model building energy code means a voluntary building energy code and standards developed and updated through a consensus process among interested persons, such as the IECC or the code used by— (A) the Council of American Building Officials, or its legal successor, International Code Council, Inc.; (B) the American Society of Heating, Refrigerating, and Air-Conditioning Engineers; or (C) other appropriate organizations. ; and (2) by adding at the end the following: (17) IECC The term IECC means the International Energy Conservation Code. (18) Indian tribe The term Indian tribe has the meaning given the term in section 4 of the Native American Housing Assistance and Self-Determination Act of 1996 ( 25 U.S.C. 4103 ). . (b) State building energy efficiency codes Section 304 of the Energy Conservation and Production Act ( 42 U.S.C. 6833 ) is amended to read as follows: 304. Updating State building energy efficiency codes (a) In general The Secretary shall— (1) encourage and support the adoption of building energy codes by States, Indian tribes, and, as appropriate, by local governments that meet or exceed the model building energy codes, or achieve equivalent or greater energy savings