1. Short title This Act may be cited as the Energy Efficient Commercial Buildings Act of 2019 . 2. Energy efficient commercial buildings deduction (a) Extension Section 179D(h) of the Internal Revenue Code of 1986 is amended by striking December 31, 2017 and inserting December 31, 2024 . (b) Increase in the maximum amount of deduction (1) In general Section 179D(b) of such Code is amended by striking $1.80 and inserting $3 . (2) Inflation adjustment Section 179D of such Code is amended by adding at the end the following new subsection: (i) Inflation adjustment In the case of a taxable year beginning after 2020, each dollar amount in subsection (b) or subsection (d)(1)(A) shall be increased by an amount equal to— (1) such dollar amount, multiplied by (2) the cost-of-living adjustment determined under section 1(f)(3) for the calendar year in which the taxable year begins, determined by substituting calendar year 2019 for calendar year 2016 in subparagraph (A)(ii) thereof. . (3) Conforming amendment Section 179D(d)(1)(A) of such Code is amended by striking by substituting $.60 for $1.80 and inserting by substituting $1 for $3 . (c) Limit on deduction limited to three-Year period Section 179D(b)(2) of such Code is amended by striking for all prior taxable years and inserting for the 3 years immediately preceding such taxable year . (d) Update of standards (1) ASHRAE standards Section 179D(c) of such Code is amended— (A) in paragraphs (1)(B)(ii) and (1)(D), by striking Standard 90.1–2007 and inserting Reference Standard 90.1 , and (B) by amending paragraph (2) to read as follows: (2) Reference Standard 90.1 The term Reference Standard 90.1 means, with respect to property, the Standard 90.1 most recently adopted (as of the date that is 2 years before the date that construction of such property begins) by the American Society of Heating, Refrigerating, and Air Conditioning Engineers and the Illuminating Engineering Society of North America. . (2) California Nonresidential Alternative Calculation Method Approval Manual