(a)        In C1 and C2 Districts mapped within R6 through R10 Districts with a letter suffix, and in C1-6A, C1-7A, C1-8A, C1-8X, C1-9A, C2-6A, C2-7A, C2-7X, C2-8A, C4-2A, C4-3A, C4-4A, C4-4D, C4-4L, C4-5A, C4-5D, C4-5X, C4-6A, C4-7A, C5-1A, C5-2A, C6-2A, C6-3A, C6-3D, C6-3X, C6-4A or C6-4X Districts, all buildings shall comply with the bulk regulations for Quality Housing buildings set forth in this Chapter, and the applicable provisions of Article II, Chapter 8 (Quality Housing Program). In C1 and C2 Districts mapped within R5D Districts, only those regulations of Article II, Chapter 8, as set forth in Section 28-01 (Applicability of this Chapter), shall apply.

(b)        In C1 and C2 Districts mapped within R6 through R10 Districts without a letter suffix and in other Commercial Districts with a residential equivalent of an R6 through R10 District without a letter suffix, the bulk regulations applicable to Quality Housing buildings may, as an alternative, be applied under the same conditions set forth in Sections 23-011, 35-22 and 35-23, provided that:

(1)        the entire building complies with the bulk regulations for Quality Housing buildings set forth in this Chapter; and

(2)        the entire building complies with the applicable provisions of Article II, Chapter 8 (Quality Housing Program).

(c)        In C1 through C6 Districts, special regulations are set forth for buildings containing long-term care facilities or philanthropic or non-profit institutions with sleeping accommodations in Section 35-012 (Special provisions for certain community facility uses).

(d)        In Commercial Districts, for Quality Housing buildings in which at least 50 percent of the dwelling units are income-restricted housing units, or at least 50 percent of its total floor area is a long-term care facility or philanthropic or non-profit institution with sleeping accommodation, the applicable bulk regulations of this Chapter may be modified for zoning lots with irregular site conditions or site planning constraints by special permit of the Board of Standards and Appeals, pursuant to Section 73-623 (Bulk modifications for certain Quality Housing buildings on irregular sites).