; (B) for a residential building with five or more dwelling units, $3,500 per dwelling unit; and (C) for a commercial building that is a zero-energy building for a period of 12 continuous months starting after the building is at least 50 percent occupied, $3 per square foot of floor area, provided that a zero-energy building may also receive the zero-energy-ready building incentive if it meets the criteria for this incentive. (3) Deep energy retrofits The following tax credit amounts shall be awarded to buildings upon completion of a deep energy retrofit— (A) for a residential building, $10,000 per dwelling unit, up to a maximum of $1,000,000 per building; and (B) for a commercial building, $25 per square foot of floor area, up to a maximum of $2,000,000 per building. (d) Tax credit recipient (1) In general The person eligible to receive a tax credit under this section shall be— (A) for a new residential building, the builder; (B) for an existing residential building that has undergone a deep energy retrofit, the builder; (C) for a new commercial building, the building owner; and (D) for an existing commercial building that has undergone a deep energy retrofit, the building owner. (2) Transfer of credit A building owner who is eligible to receive a tax credit under subparagraphs (C) and (D) of paragraph (1) may transfer such tax credit to the architect, builder, or contractor. (e) Exclusions A building project is not eligible for tax credits under this section if the owner or builder has used another Federal tax incentive for the same project, including incentives under sections 25C, 25D, and 179D of this title. (f) Sunset of tax credit authority The tax credit authority under this section shall terminate— (1) for zero-energy and zero-energy-ready residential buildings, one year after the Secretary of Energy determines by rule that such buildings accounted for at least 20 percent of new residential buildings in the most recent calendar year