R4B is a residential zoning district governed by ZR 23-22, with residential far of 1, a maximum building height of 25 feet.
These are the figures the engine applies when it models a lot in R4B. Where a rule differs between a narrow and a wide street, both are shown.
| Residential FAR | 1 | ZR 23-22 |
|---|---|---|
| Community facility FAR | 2 | ZR 23-22 |
| Commercial overlay FAR | 2 | ZR 33-121 |
| Street wall base, maximum | 25 ft | ZR 23-22 |
|---|---|---|
| Maximum building height | 25 ft | ZR 23-22 |
| Front yard | 5 ft | ZR 23-45 |
|---|---|---|
| Side yard | 5 ft | ZR 23-46 |
| Rear yard | 20 ft | ZR 23-47 |
| Lot coverage — interior lot | 60% | |
| Lot coverage — corner lot | 80% |
| Minimum lot area, practical | 1,500 sf | |
|---|---|---|
| Minimum lot width | 18 ft | |
| Parking spaces per dwelling unit | 1 | ZR 25-23 |
At 1 FAR, a 10,000 square foot lot in R4B carries roughly 10,000 square feet of zoning floor area.
That is the ceiling, not the answer. The height envelope, required yards, lot shape, street width, overlays and any special district all cut into it. Running the real lot is the only way to know which constraint binds first.
A section through the R4B envelope, drawn to scale from the figures in the table above. The solid shape is as of right; where the district carries a City of Yes uplift, the dashed outline is what affordable housing adds.
Diagrammatic. It shows the governing heights and the setback on a regular lot, not your lot: the sky exposure plane, lot shape, corner conditions and any overlay all reshape this in practice.
Every area of the city zoned R4B, from NYC Planning’s published zoning district layer.
The sentences below are quoted verbatim from the Zoning Resolution text the engine is built against, for the R4B rules we have mirrored and checked by hand. Check us against them.
“For all other types of multiple dwelling residences , the applicable dwelling unit factor shall be 680.”
“R3A R4-1 R4A R4B R5A R5B R5D 2,375 25”
“R3A R4-1 R4A R4B R5A R5B R5D 2,375 25”
“In R1 through R5 Districts, a rear yard with a minimum depth of five feet shall be provided where such rear lot line coincides with a side lot line of an adjoining zoning lot .”
“and in all other districts, the minimum width shall be five feet.”
“In R3, R4 and R5 Districts, the minimum dimension between a legally required window and a side lot line shall be 15 feet.”
Use groups permitted in R4 districts:
Underbuilt here means a lot of at least 2,500 square feet, built to less than half its residential floor area, in private hands, with at least 20,000 square feet of unused capacity. From PLUTO 26v2. How we counted.
R4B has a residential far of 1, set by ZR 23-22. On a 10,000 square foot lot that is about 10,000 square feet of zoning floor area before any bonus, and before the height envelope and yard requirements are applied.
The maximum building height in R4B is 25 feet on a wide street, with a street wall rising to between 0 and 25 feet before a required setback. Height is measured and applied under ZR 23-22.
Source: NYC Planning zoning districts.