C6-4A Zoning District — New York City

Roughly 260 tax lots carry this designation on record, and their buildings are both tall and old: a median height of 10 stories, with 60% of recorded buildings rising above 6 floors, on a stock where 86% predates 1940 and the median construction year is 1910. Only 2% of buildings date from the 1945-to-1975 boom and 9% from 2000 or later — nearly all of what stands here arrived before the war and has stayed since. A median that old, paired with a 10-story height this consistent, describes a prewar core built up vertically far beyond the low-rise pattern common to similarly old stock.

Nearly half of these lots — 48% — also carry a recorded historic-district designation, layering landmark review on top of the height already recorded here. Office buildings lead the recorded building classes at 36%, condominium classifications follow at 20%, and elevator apartment buildings add 16%. That combination of a 10-story median height and a 48% historic-district share layers two distinct patterns — density and preservation — on the same recorded lots.

By land use, commercial-and-office use covers 44% of lots and mixed residential-and-commercial use 39%, with multi-family elevator buildings at 10%. Residential use overall reaches 52% of lots, and the records count 7,549 homes across the designation. Lots run to a median of 4,600 square feet, with the 90th percentile at 14,250, a moderate spread for a designation built this tall. That lot-size figure sits alongside a residential share just over half, meaning the recorded office and mixed-use classes above account for a real share of what stands on these 260 lots.

Development headroom here is comparatively tight against the height recorded above: 61% of lots show floor area below their allowance, with a median residual of 2 FAR, alongside heavy historic-district review on many of these parcels. None of these lots sit inside the mapped Special Flood Hazard Area. The rules tables above carry the governing FAR and height figures with their citations; a specific lot's recorded historic status is tracked at the level of the individual tax lot.

Every stat family tracked for this designation reports in full here, with no gaps marked for missing coverage. That matters because three traits recorded together — a 10-story median height, a 48% historic-district share, and a comparatively tight 61% headroom share — are not a combination this designation's own profile shows in any other proportion. Each lot's own recorded historic and floor-area status is checkable individually, drawn from the same complete file as the shares above.