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.

C2-3 is a commercial overlay district with a depth of 150 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.

C2-3 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.

R5 districts have a floor area ratio (FAR) of 1.25, which typically produces three-story attached houses and small apartment houses. With a height limit of 40 feet, R5 districts can provide a transition between lower- and higher-density neighborhoods and are widely mapped in Brooklyn, Queens and the Bronx.

To ensure compatibility with existing neighborhood scale, the maximum street wall height of a new building is 30 feet, with a 15-foot setback and a maximum building height of 40 feet. Front yards for all housing types must be 10 feet deep or if deeper, a minimum of 18 feet to prevent cars parked on-site from protruding onto the sidewalk. Detached houses must have two side yards that total at least 13 feet with a minimum width of five feet for each one.

Semi-detached buildings and the end buildings in a row of attached houses need one eight-foot-wide side yard. The maximum street wall length for a row of attached buildings on a single zoning lot is 185 feet. Off-street parking is required for 85% of the dwelling units.

On blocks entirely within an R5 zone, optional regulations may be used to develop infill housing when the area is already predominately built-up. A higher FAR of 1.35 is available for qualifying sites, as well as 55% lot coverage, allowing for much larger buildings with more dwelling units. Off-street parking is generally required for two-thirds of the dwelling units.