For residences in Commercial and Mixed Use Districts, the provisions of Sections 25-541 and 36-441 (Joint facilities) shall not apply. In lieu thereof, the provisions of this Section shall apply.

Required accessory off-street parking spaces may be provided in facilities designed to serve jointly two or more buildings or zoning lots, provided that the number of spaces in such joint facilities shall be not less than that required for the combined number of dwelling units in such buildings or zoning lots, and provided that the design and layout of such joint facilities meets the standards of adequacy set forth in regulations promulgated by the Commissioner of Buildings.