3901 9 Avenue, Brooklyn 11232 is a 9,533 square foot lot zoned R7A. RunEnvelope’s engine finds an as-of-right scheme with homes of 47,760 sf (AIRS Senior Housing (100% Affordable)), against 1,962 sf built on the lot today.
That leaves 45,798 sf more floor area than stands here now, if the existing building were replaced. The largest scheme with homes and no affordability obligation holds 38,132 sf (Max Apartments).
City Planning’s PLUTO file lists a residential FAR of 4.00 for this lot, which at 9,533 sf of land is 38,132 sf. The engine’s largest residential-only scheme without an affordability obligation (Max Apartments) holds 38,132 sf, close to that simple multiplication.
Quality Housing height limit in R7A on a wide street: 85 ft (115 ft with the affordability preference). From the district’s rule set.
The largest 6 as-of-right schemes RunEnvelope’s engine produced for this lot, by zoning floor area. A full study also models the building itself: floor plates, heights, setbacks, unit mix and parking.
| Scheme | Type | Floor area | FAR | Homes |
|---|---|---|---|---|
| AIRS Senior Housing (100% Affordable) | Income-restricted housing | 47,760 | 5.01 | 57 |
| Max Apartments | Housing | 38,132 | 4.00 | 56 |
| Commercial Overlay | Mixed use with homes | 38,132 | 4.00 | 33 |
| Community Facility | Community facility | 38,132 | 4.00 | None |
| Residential + Community Facility | Mixed use with homes | 38,124 | 4.00 | 35 |
| Shared Housing (SRO) | Shared housing (rooms) | 37,875 | 3.97 | 129 rooms |
Floor area is zoning floor area in square feet. Highlighted: the largest scheme with homes. Income-restricted schemes (Universal Affordability Preference, AIRS senior housing) require a share or all of the homes to be affordable. Shared housing counts rooms, not apartments. Schemes that need a landmark transfer of development rights, the FRESH food store bonus or a stack of every program are left off this page; the full study shows them.
As-of-right only: what the Zoning Resolution allows without a variance, special permit or rezoning. Computed by RunEnvelope’s zoning engine on October 23, 2026 from PLUTO 26v2 lot data, in screening mode: the engine uses the City’s recorded lot area and dimensions, not a surveyed lot outline.
This is not a professional opinion, an appraisal or a statement that anything will or should be built here. Existing tenants, leases and the owner’s plans are not part of it.
Why this lot has a page: we publish pages only for lots that clear a set of data quality and headroom tests.
The closest published lots in Brooklyn, same zoning district first. All Brooklyn lots.