meets all procedures and detailed methods for calculating energy consumption levels as required by the Secretary, and (ii) which provides such forms as required to be filed by the Secretary in connection with energy consumption levels and the deduction allowed under this section. . (b) Conforming amendment The table of sections for part VI of subchapter B of chapter 1 is amended by striking the item relating to section 179D and inserting after the item relating to section 179C the following item: Sec. 179D. Energy efficient commercial building deduction. . (c) Effective date The amendments made by this section shall apply to any qualified building placed in service after December 31, 2018. 305. Energy efficiency deduction for existing commercial buildings (a) In general Part VI of subchapter B of chapter 1 is amended by inserting after section 179E the following new section: 179F. Deduction for energy efficiency improvements to commercial buildings (a) In general There shall be allowed as a deduction an amount equal to the lesser of— (1) the applicable amount for the qualified building based on energy efficiency improvements made by the taxpayer and placed in service during the taxable year, or (2) the amount paid or incurred by the taxpayer for energy efficiency improvements made to the qualified building which were placed in service during the taxable year. (b) Applicable amount (1) In general For purposes of subsection (a), the applicable amount shall be an amount equal to the product of— (A) the applicable dollar value, and (B) the square footage of the qualified building. (2) Applicable dollar value For purposes of paragraph (1), the applicable dollar value shall be an amount equal to $1.25 increased (but not above $9.25) by $0.50 for every 5 percentage points by which the efficiency ratio for the qualified building is certified to be greater than 20 percent. (3) Efficiency ratio (A) In general For purposes of this section, the efficiency ratio of a qualified building shall be equal to the quotient,