R4B Zoning in NYC: FAR, Height and Setbacks

R4B is a low-rise contextual district for one- and two-family houses, including attached rowhouses, with a 25 ft height limit.

Floor area (FAR)

• Standard maximum residential FAR: 1.00 (ZR 23-21).
• On a qualifying residential site: 1.50 FAR.
• Community facility FAR: 2.00, with lot coverage up to 60% on corner lots and 55% on interior or through lots (ZR 24-11). Some uses, such as non-profit institutions with sleeping accommodations, can have lower limits (ZR 24-111).
• FAR (floor area ratio) is total zoning floor area divided by lot area. On a 2,500 sq ft lot, 1.00 FAR means 2,500 sq ft of floor area.

Height and setbacks

• Maximum building height is 25 ft (ZR 23-422).
• On qualifying residential sites (and for qualifying senior housing), the limits are a 35 ft maximum base height and a 45 ft maximum building height, with a setback above the base (ZR 23-424).

Yards, lot coverage and lot size

• Front yard: 5 ft deep (ZR 23-321). On a corner lot, one front yard can be 5 ft shallower, and you can match a shallower neighboring front yard, but never less than 5 ft. Here the front yard must also line up between the shallowest and deepest neighboring front yards (it never needs to exceed 15 ft).
• Side yards: Detached houses need two side yards, each at least 5 ft wide (ZR 23-332). Semi-detached and zero lot line houses need one 5 ft side yard, plus an 8 ft open area between buildings where the neighbor is a one- or two-family house. Attached rowhouses need no side yard, but any open strip along a side lot line must be at least 5 ft wide.
• Rear yard: On interior lots, detached and zero lot line buildings need a 20 ft rear yard up to 75 ft high. Semi-detached and attached buildings need 30 ft on lots narrower than 40 ft, and 20 ft on lots 40 ft or wider. Where a building rises above 75 ft, that portion needs 30 ft (ZR 23-342). Shallow lots that existed in 1961 can get a reduced rear yard, never under 10 ft.
• Lot coverage: For one- and two-family homes: 60% on interior and through lots, 80% on corner lots (ZR 23-361). Apartment buildings, where permitted, can cover 80% of an interior lot and 100% of a corner lot.
• Minimum lot size: 2,375 sq ft and 25 ft wide for a detached or zero lot line one- or two-family house; 1,700 sq ft and 18 ft wide for other residences where they are permitted (ZR 23-11).

What you can build in R4B

One- and two-family houses: detached, semi-detached, attached (rowhouses) or zero lot line (ZR 22-122). On a qualifying residential site, any type of residence is permitted.

City of Yes changes

• City of Yes for Housing Opportunity (adopted December 5, 2024) added a higher tier for qualifying residential sites: 1.50 FAR here instead of 1.00, a height limit of 45 ft, and any type of residence (ZR 23-21, 23-424, 22-122).
• A qualifying residential site is, in short: a lot of at least 5,000 sq ft in the Greater Transit Zone with frontage on a wide street or the short end of a block (not in R1 or R2); or a lot with an existing community facility building (with conditions); or, in R3-2, R4, R5 and R5B, a lot with qualifying senior housing. Where residential floor area on such a site exceeds 50,000 sq ft, part of it must be affordable (ZR 12-10).
• It also allowed ancillary dwelling units (ADUs): one extra home of up to 800 sq ft per one- or two-family residence, with conditions (ZR 12-10).

R4B zoning FAQ

Nearby districts

• R4
• R4-1
• R4A
• R5