1. Short title This Act may be cited as the New Home Energy Efficiency Act . 2. Extension of new energy efficient home credit (a) In general Subsection (g) of section 45L of the Internal Revenue Code of 1986 is amended by striking December 31, 2017 and inserting December 31, 2020 . (b) Effective date The amendments made by this section shall apply to qualified new energy efficient homes acquired after December 31, 2017. 3. Updating new energy efficient home credit (a) In general Section 45L of the Internal Revenue Code of 1986, as amended by section 2, is amended— (1) in subsection (a)(2)— (A) in subparagraph (A), by striking $2,000 and inserting $2,500 ; and (B) in subparagraph (B), by inserting or (4) after paragraph (3) ; (2) in subsection (b)— (A) in paragraph (2)(B), by striking this section and inserting the New Home Energy Efficiency Act ; and (B) by adding at the end the following: (5) 2018 IECC (A) In general The term 2018 IECC means the 2018 International Energy Conservation Code, as such Code (including supplements) is in effect on the date of the enactment of the New Home Energy Efficiency Act . (B) Special rule For purposes of subsection (c)(1)(B)(i)(I), in determining whether a dwelling unit has been constructed in accordance with the standards of chapter 4 of the 2018 IECC by achieving a level of energy efficiency which meets Section R406.4 (N1106.4) of such Code, such determination shall be made without accounting for on-site energy generation.