C2 districts are mapped as commercial overlays within residence districts. They are mapped along streets that serve the local retail needs of the surrounding residential neighborhood.

Typical retail uses include grocery stores, restaurants and beauty parlors, catering to the immediate neighborhood. C2 districts permit a slightly wider range of uses than in C1, such as funeral homes and repair services. In mixed residential/commercial buildings, commercial uses are limited to one or two floors and must always be located below the residential use.

C2-4 is a commercial overlay district with a depth of 100 feet. These districts are largely found in throughout the city's lower and medium-density districts.

Overlay districts are distinct from other commercial districts in that residential bulk is governed by the residence district within which the overlay is mapped. All other commercial districts that permit residential use are assigned a specific residential district equivalent.

When residences are constructed in any commercial district, certain regulations that apply in residence districts are waived, such as front and side yard requirements.

C2-4 overlays mapped in R1 through R5 districts have a maximum commercial FAR of 1.0. When mapped in R6 through R10 districts, however, the maximum commercial FAR is 2.0.

Commercial parking requirements are highly complex, reflecting traffic-generating qualities of the various commercial uses, their size and proximity to mass transit. Generally, the lower the numerical suffix, the more off-street parking is required in a particular district.

The Quality Housing bulk regulations, which are mandatory in R6A districts, typically produce high lot coverage, six- or seven-story apartment buildings set on or near the street line. Designed to be compatible with existing buildings found in older neighborhoods, R6A districts are mapped in the Bronx, Brooklyn and Queens.

The floor area ratio (FAR) in R6A districts is 3.0. Above a base height of 40 to 60 feet, the building must be set back to a depth of 10 feet on a wide street and 15 feet on a narrow street before rising to its maximum height of 70 feet. To preserve the traditional streetscape, the street wall of a new building can be no closer to the street line than any building within 150 feet on the same block, up to a depth of 15 feet. The area between a building's street wall and the street line must be landscaped.

Off-street parking, which is not allowed in front of a building, is required for 50% of a building, is required for 50% of a building's dwelling units, or waived if five or fewer spaces are required.