Two FARs instead of one
In R6 through R12, ZR 23-22 sets “separate maximum residential floor area ratios” for zoning lots containing standard residences and zoning lots containing qualifying affordable housing or qualifying senior housing. Qualifying affordable housing means an MIH development in a Mandatory Inclusionary Housing area, a UAP development, or a building under an affordable housing regulatory agreement (ZR 12-10).
| District | Standard | Qualifying affordable or senior |
|---|---|---|
| R6 (beyond 100 ft of a wide street) | 2.20 | 3.90 |
| R6A, R6-1, R7B, and R6 within 100 ft of a wide street | 3.00 | 3.90 |
| R6B | 2.00 | 2.40 |
| R6D, R6-2 | 2.50 | 3.00 |
| R7A | 4.00 | 5.01 |
| R7D | 4.66 | 5.60 |
| R7X, R7-3 | 5.00 | 6.00 |
| R8B | 4.00 | 4.80 |
| R9A, R9 | 7.52 | 9.02 |
| R10A, R10X, R10 | 10.00 | 12.00 |
| R11 | 12.00 | 15.00 |
| R12 | 15.00 | 18.00 |
R8 and the R6 and R7-1/R7-2 rows near wide streets have footnoted variants; see the section for every district.
R1 through R5 follow the same pattern in ZR 23-21, with a higher FAR for “qualifying residential sites”: 1.50 rising to 2.00 in R5, R5A and R5B, and 1.00 rising to 1.50 in R4, R4-1, R4A and R4B.
A UAP development is a development or enlargement outside a Mandatory Inclusionary Housing area that provides affordable housing; its residential FAR may exceed the standard FAR “only by the amount of affordable housing provided” (ZR 27-111). For a UAP site the affordable units are restricted to households at a weighted average of 60 percent of the income index, with no more than three income bands.
What it means for a donor lot
- Lot area
- 5,000 sf
- Built today
- 8,000 sf
- Unused at the standard FAR (4.00)
- 20,000 − 8,000 = 12,000 sf
- Unused at the qualifying FAR (5.01)
- 25,050 − 8,000 = 17,050 sf
- Difference
- 5,050 sf
The 5,050 sf difference only exists on a zoning lot whose building provides the affordable housing. Once the lots merge, it belongs to the buyer's project, and the buyer earns it by restricting that floor area as affordable housing under ZR 27-111. A donor quoting the larger figure is asking to be paid for the buyer's affordability commitment.
For landmark donors the question is narrower. ZR 75-422 caps the transfer at “the maximum floor area allowed by the applicable district regulations” less what is built, and excludes “any other form of bonus whether as of right or by discretionary action.” Whether a landmark can count the qualifying column toward what it sends is a question to put to land use counsel before anyone prices it.
What it means for a receiving lot
City of Yes also set separate heights. ZR 23-432 gives a higher maximum base height and building height for zoning lots containing qualifying affordable or senior housing, which gives transferred floor area more room to fit.
| District | Standard | Qualifying affordable or senior |
|---|---|---|
| R6B | 55 | 65 |
| R6A, R6-1 | 75 | 95 |
| R7A | 85 | 115 |
| R7X, R7-3 | 125 | 145 |
| R9A (within 100 ft of a wide street) | 145 | 185 |
- Developable on lot A after the merger, standard
- 36,000 sf
- What lot A's envelope holds, standard (85 ft)
- 30,750 sf
- Developable, qualifying affordable
- 46,100 sf
- What lot A's envelope holds, qualifying (115 ft)
- 39,750 sf
The taller qualifying envelope holds 9,000 sf more, but the qualifying FAR adds even more floor area, so the shortfall grows from 5,250 sf to 6,350 sf. Floor-by-floor working is in Part 7.
Other changes that move the numbers
- ■Landmark transfers. The LPC says City of Yes added ZR 75-42, widened the receiving area from adjacent lots to the block and across the street, replaced ULURP with Chair certification and made individual landmarks in historic districts eligible (LPC fact sheet). See Part 5.
- ■Floor area exemptions. In buildings with multiple dwellings, ZR 23-23 lets residential amenity space up to 5 percent of the building's residential floor area, and qualifying corridors, be exempted from floor area. The same zoning floor area can now hold more gross building.
- ■Units. The maximum number of dwelling units is residential floor area divided by a dwelling unit factor of 680, and qualifying senior housing has no factor at all (ZR 23-52). Bought floor area raises the unit cap by the same arithmetic.
A City of Yes checklist for an air rights deal
- 01
Quote the donor's unused floor area at the standard FAR
Use the standard column of ZR 23-22 (or the standard zoning lot column of ZR 23-21) less everything built on the zoning lot. Treat the qualifying column as the buyer's to earn. - 02
Decide which program the receiving building will use
A standard building and a UAP or qualifying senior building have different FARs, heights and unit rules on the same lot. The usable share of a transfer can differ between them, so model both before agreeing a price. - 03
Check the receiving envelope under that program
Use the ZR 23-432 heights for the program chosen, then yards and coverage. The Part 2 merger shows the qualifying envelope can still fall short of the qualifying FAR. - 04
For landmarks, settle the transferable amount first
Ask counsel how ZR 75-422 treats the qualifying column for the granting lot before either side relies on a figure.
Reading prices across the line
The RunEnvelope Land Index divides each land sale by buildable square feet under today's rules. Of its qualifying sales, 3,885 predate City of Yes and 2,469 follow it. An earlier sale is divided by rights the buyer did not yet have, which understates what it paid per foot at the time. Compare quarters on either side of 2024-12-05 with care, and expect air rights negotiated before that date to have been priced on the old rules.
Sources, checked 2026-10-26
- ZR 23-22, Floor area regulations for R6 through R12 districts
- ZR 23-21, Floor area regulations for R1 through R5 districts
- ZR 12-10, Definitions: zoning lot, floor area, floor area ratio, party in interest
- ZR 27-111, Definitions (UAP development, affordable housing unit)
- ZR 23-432, Height and setback requirements (R6 through R12)
- ZR 23-23, Special floor area provisions for multiple dwelling residences
- ZR 23-52, Maximum number of dwelling units
- ZR 75-42, 75-421 and 75-422, Transfer of development rights from landmarks
- NYC Landmarks Preservation Commission, Transfer of Development Rights fact sheet (June 2026)
- RunEnvelope Land Index: method, sales rules and CSV
Not legal advice. This guide explains the Zoning Resolution in plain English and can be out of date the day the text is amended. Before you price, buy or sell development rights, have a land use attorney and the filing architect confirm the zoning lot, the documents and the numbers.