C6-4X Zoning District — New York City

What stands out about this designation is the contrast between its lot fabric and its recorded capacity. The median lot runs just 1,912 square feet — small by any citywide comparison — yet the 90th percentile reaches 17,281 square feet, meaning a handful of much larger parcels sit alongside a great many small ones, on roughly 75 tax lots in total. Against that tight median, 77% of lots record floor area below their allowance, with a median gap of 6.1 — the pairing of small lots and wide recorded headroom that shows up when older, low buildings sit on parcels a current allowance would let carry more.

The age profile is heavily prewar: 81% of recorded buildings predate 1940, and the median construction year is 1920. None of the stock, 0%, dates from the 1945-to-1975 building boom — a complete gap in that middle era — while 18% has been built since 2000, meaning what limited new construction exists here has arrived recently rather than during the postwar decades. Very little of what stands today, in other words, was added in the generation right after the boom's own construction window closed.

By recorded building class, the largest recorded category holds 39% of the stock, with office buildings following at 17% and elevator apartment buildings at 16%. Land use runs mixed-residential-and-commercial at 65% of lots, commercial-and-office at 27%, and multi-family elevator use at 4%. Despite that commercial-sounding land-use split, 69% of lots are recorded as residential, and the file counts 4,784 housing units — a designation whose land-use labels lean commercial even where the underlying use recorded on most lots is residential.

Buildings here run low: a median height of 4 stories, with 25% of the recorded stock rising above 6 floors — modest compared to a designation with this much recorded development headroom. On the flood map, 4% of these roughly 75 tax lots fall inside the mapped Special Flood Hazard Area, a small but real minority worth checking parcel by parcel rather than assuming for the whole designation. The rules tables above carry the specific allowances behind that 6.1 median gap, with citations; this page describes only what is recorded as built, not what a given lot could add.

Taken together, this designation describes a corner of the map where lot lines run tight, buildings have stayed low and mostly prewar, and recorded floor area sits well under what current allowances would support. That is a distinct pattern from a designation with similar headroom numbers on much larger parcels — smaller lots concentrate any future change onto more individual owners rather than a few larger sites. Each lot's own page carries its specific recorded figures alongside the citywide numbers described here.