in the maximum amount of deduction (1) In general Section 179D(b) is amended by striking $1.80 and inserting $3 . (2) Inflation adjustment Section 179D , as amended by subsection (a), is amended by redesignating subsection (h) as subsection (i) and by inserting after subsection (g) the following new subsection: (h) 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) 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) 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) 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 Section 179D(d)(2) is amended by striking 2005 and inserting 2019 . (e) Change in efficiency standards Section 179D(c)(1)(D) is amended by striking 50 and inserting 30 . (f) Deadwood Section 179D , as amended by subsections (a) and (b), is amended by striking