R4-1 Zoning District — New York City

Two-family homes are the single most common recorded building class on lots carrying this designation, at 47% — the highest two-family share of any designation profiled in this batch. One-family homes follow at 36%, and walk-up apartment buildings add 11%, describing a stock built up around paired and small multi-unit houses rather than single detached ones or larger apartment buildings.

That composition sits on a substantially prewar timeline: the median construction year is 1930, and 65% of recorded buildings predate 1940 — one of the deeper prewar concentrations in this batch. The 1945-1975 postwar boom added a further 21% to the stock, and 6% of buildings have gone up since 2000, a modest trickle of recent construction on top of an otherwise old core.

Land use closely follows the building-class mix: one- and two-family use covers 83% of lots, multi-family walk-up use 11%, and vacant land 3%. The designation is mapped across roughly 52,000 tax lots citywide. Overall 95% of lots are coded residential, and the file counts 96,270 homes across the designation.

Lots run compact: a median of 2,500 square feet, with the 90th percentile reaching 4,000 square feet. Buildings rise to a median of 2 stories, with 0% recorded above 6 floors. Development room is fairly wide for a stock this old — 75% of lots record floor area below their allowance, with a median residual of 0.3 FAR. Flood exposure is modest, at 5% of lots. None of these lots carry historic-district status on record. Every figure here is a recorded fact about existing buildings, not a statement of what the zoning permits — that detail, cited section by section, belongs to the tables above.

The two-family concentration described above, the highest of any designation in this batch, sits on a stock that is also substantially prewar — 65% of buildings predate 1940, more than double the 21% share from the 1945-to-1975 postwar boom that followed it. Read together, those figures describe a designation whose defining housing type was largely built before the war and has simply persisted since, rather than one that grew up during the boom years the way several other designations in this batch did. That persistence shows up in the headroom figures too: 75% of lots carry recorded floor area beneath their allowance, at a 0.3 FAR median residual — a real but not exceptional margin for a stock this old — spread across roughly 52,000 lots that show no recorded historic-district status at all. The 5% flood share is similarly modest, leaving construction era rather than any mapped overlay as the defining fact of this designation's file.