Glossary & Appendix
A combined reference guide to the terms, acronyms, processes, and programs that come up in CB6's work. Search by word, filter by topic area, or browse. Each entry defines a concept once in plain language. Process guides, agency lists, and reference tools are in the Appendix tabs below.
NYC zoning codes follow a consistent logic. The letter tells you the district type. The first number tells you the family — higher generally means more density. Numbers after the hyphen indicate subdistrict levels. Letters at the end (A, B, D, X) specify contextual or mapped variants.
The most common zoning category in NYC — roughly three-quarters of all zoned land. In CB6 you'll mostly encounter R5 through R7 designations. Note: residential zoning doesn't mean housing-only. Schools, medical offices, and houses of worship are permitted under separate bulk rules.
| Code | What It Means |
|---|---|
| R1 | Lowest-density residential. Detached homes, large lots. Not mapped in CB6. |
| R2 | Low-density. Single-family detached homes. Not common in CB6. |
| R3 | Low-density, includes some attached housing types. |
| R4 | Lower-to-moderate density. Subcategories R4-1, R4A, R4B apply specific controls on form and parking. |
| R5 | Moderate density. Often a transition zone between lower-density residential and active commercial corridors. |
| R6 ★ | Medium density. Commonly associated with attached and multi-family buildings — much of Park Slope and Carroll Gardens. |
| R7 ★ | Medium-to-higher density. R7A (contextual, matches neighborhood scale) and R7X (allows greater height) apply different form rules. Core of the Gowanus rezoning area. |
| R8 | High density. Substantial residential bulk. Mapped in parts of the Gowanus rezoning area (M1-6A/R8 pairing). |
| R9 | Very high density. Significant residential capacity, often in mixed urban contexts. |
| R10 | Highest density in the R-series. Mapped in the most intense residential contexts. |
Commercial districts range from C1 (neighborhood retail) to C8 (automotive/heavy commercial). In CB6 the C4, C5, and C6 families are most common. C1 and C2 are frequently mapped as thin overlays on residential blocks — that's what makes ground-floor retail on Fifth Avenue and Smith Street legal.
| Code | What It Means |
|---|---|
| C1 ★ | Neighborhood-scale retail and services. Usually mapped as a thin overlay on residential blocks — governs ground-floor storefronts on corridors like Fifth Avenue and Smith Street without changing the underlying residential zone. |
| C2 ★ | Broader local commercial range than C1. Often mapped as an overlay on residential blocks in mixed-use neighborhood conditions. |
| C3 | Waterfront recreation-oriented. Relevant near the CB6 waterfront. |
| C4 | General commercial corridor activity. C4-3, C4-3A, C4-4A, and C4-4D are all mapped in CB6. |
| C5 | Major central commercial. C5-4 and C5-2A appear in CB6's denser commercial areas. |
| C6 ★ | High-density central commercial with substantial mixed-use character. Most common commercial family in CB6 — subdistrict variants from C6-1 through C6-9. C6-3A, C6-3X, C6-4, C6-4.5 all appear in CB6. |
| C7 | Amusement-oriented. Not mapped in CB6. |
| C8 | Commercial service and automotive-oriented. Not mapped in CB6. |
M districts run from light industrial (M1) to heavy industrial (M3). In CB6 most are concentrated in Gowanus and Red Hook. The D suffix is critical — M1-1D through M1-5D districts can permit residential use under stated conditions, which is why housing sometimes appears in areas that look purely industrial on the map.
| Code | What It Means |
|---|---|
| M1 ★ | Light manufacturing. Allows light industrial, maker, business-support uses. Multiple M1 subdistricts mapped in CB6: M1-1, M1-1D, M1-2, M1-2D, M1-4, M1-5. |
| M2 | Medium manufacturing. More intensive than M1. M2-1 and M2-3 are mapped in CB6 (primarily Red Hook and Gowanus waterfront). |
| M3 | Heavy manufacturing. Most intensive industrial activity. M3-1 is mapped in parts of Red Hook. |
| M1-D ⚠ | Key distinction: M1-D districts (M1-1D, M1-2D) can permit residential use under stated conditions per ZR §42-311. This is why housing sometimes appears in industrial-looking areas — the D designation makes it possible. |
M/R paired designations combine industrial and residential rules on the same block. Read them in two parts: the left side is the manufacturing framework, the right side is the residential framework. A developer can build under either or combine both in a mixed-use building. These are central to the Gowanus rezoning.
| Code | What It Means |
|---|---|
| M1-1/R5 | Light manufacturing paired with lower-to-moderate-density residential. |
| M1-4/R6 | Higher M1 framework paired with medium-density residential. |
| M1-4/R7-2 | Higher M1 paired with higher-density residential. |
| M1-4/R7A ★ | Higher M1 paired with contextual R7A. The most common pairing in the core Gowanus area. |
| M1-4/R7X | Higher M1 paired with contextual R7X, which allows greater height than R7A. |
| M1-6A/R8 | High-capacity M1 variant paired with high-density R8. Mapped in the most intense parts of the Gowanus rezoning area. |
FAR is the single most important number in determining how much can be built on a given lot. It expresses the ratio of total building floor area to the area of the lot.
The A, B, and X suffixes aren't just technical labels. They reflect a specific planning response to a real problem: after the 1961 Zoning Resolution, new buildings often sat awkwardly among older ones — taller, more set back from the street, out of scale. Contextual districts were created to prevent this.
| Suffix | What It Does | CB6 Examples |
|---|---|---|
| A | Contextual — requires new buildings to match scale, massing, and street wall of existing fabric. Lower height limit, no setback towers. | R6A, R7A, C6-3A |
| B | Contextual with specific lower-density form controls — typically used for rowhouse and small apartment building contexts. | R6B, R4B |
| X | Contextual but allows greater height than A — still keeps street wall, but building can be taller within that form. | R7X, C6-3X |
| D | In M1 districts: residential use permitted under stated conditions (ZR §42-311). Also used in some C districts for specific mapped variants. | M1-1D, C4-4D |
C1 and C2 districts appear in two forms. As standalone districts, they function like any other zoning. But more often in CB6 they are mapped as thin overlays on top of residential zones — one to two lots deep along an active corridor. The overlay opens the ground floor to retail without changing the underlying residential zone.
Process guides, agency lists, programs, and reference tools — supporting material that goes beyond single definitions.