Accessory Structures in New York, NY (2026)
9 verified accessory structures rules for New York, New York, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
New York City legalized Ancillary Dwelling Units (ADUs) citywide on December 5, 2024 through the City of Yes for Housing Opportunity text amendment. An ADU is an additional dwelling unit of up to 800 square feet permitted on the same zoning lot as a single- or two-family residence, limited to one ADU per residence and requiring owner primary-residency.
NYC Ancillary Dwelling Units (ZR 12-10, City of Yes)
Some RestrictionsNYC Zoning Resolution Section 12-10, definition of "ancillary dwelling unit" (City of Yes for Housing Opportunity, adopted Dec. 5, 2024)
An "ancillary dwelling unit" is an additional dwelling unit, permitted on the same zoning lot as a single- or two-family residence that does not exceed eight hundred square feet of floor area. Only one ancillary dwelling unit shall be permitted per every single- or two-family residence on a zoning lot. At the time of initial occupancy for an ancillary dwelling unit, the zoning lot on which the ...
ADU Permits
New York City does not have a general-purpose ADU ordinance. Most accessory dwelling units, including basement and cellar apartments, remain illegal under the NYC Zoning Resolution and NYC Building Code, except under the Local Law 22 of 2024 basement and cellar conversion pilot in specific community districts.
New York City ADU Permit Restrictions
Heavy RestrictionsADU Impact Fees
New York City does not charge impact fees on accessory dwelling units because it has no general ADU ordinance. Local Law 22 of 2024 pilot conversions pay standard DOB and HPD filing, plan-exam, and inspection fees only, with no school, park, or transportation impact fees.
New York City ADU Fee Framework
Some RestrictionsADU Owner Occupancy
The Local Law 22 of 2024 basement and cellar legalization pilot requires the owner to occupy the building as a primary residence at the time of application. Outside the pilot, NYC has no ADU framework, so owner-occupancy rules don't apply.
New York City Basement Conversion Owner-Occupancy
Heavy RestrictionsADU Rental Restrictions
Local Law 18 of 2022 (NYC short-term rental registration) prohibits short-term rentals in any dwelling unit unless the host is present and the unit is registered with the Mayor's Office of Special Enforcement. ADUs and basement units are not eligible for STR registration.
New York City ADU and Basement Rental Rules
Heavy RestrictionsShed Rules
New York City permits sheds, tool rooms, and similar accessory storage buildings in required rear yards in all Residence Districts, provided they do not exceed 10 feet in height above the level of the rear yard. They are permitted only in rear yards, not front or side yards.
NYC Backyard Sheds (Zoning Resolution 23-341)
Some RestrictionsNYC Zoning Resolution Section 23-341, Permitted obstructions in required rear yards or rear yard equivalents
In all Residence Districts, the following obstructions shall be permitted within a required rear yard or rear yard equivalent ... Sheds, tool rooms or other similar accessory buildings or other structures for domestic or agricultural storage, with a height not exceeding 10 feet above the level of the rear yard or rear yard equivalent ... Noncommercial accessory greenhouses, limited to one story...
Garage Conversions
Following City of Yes for Housing Opportunity, New York City allows legally existing garages (attached, within the home, or detached) on 1- and 2-family lots to be converted into ancillary dwelling units of up to 800 square feet, with non-compliant setbacks of the original garage generally retained and required parking eliminable where zoning permits.
NYC Garage Conversions to ADUs (Appendix U, City of Yes)
Some RestrictionsNYC Building Code Appendix U Sections U101.2 and U202.5 (Ancillary Dwelling Units), added by Local Law 127 of 2024
An ADU in a cellar must have a clear ceiling height that is at least 2 feet above the grade plane. ... All habitable rooms in basements shall have a minimum clear ceiling height of 7 feet. The minimum clear ceiling height of all habitable rooms in a cellar shall be 7 feet.
Carport Rules
Carports in NYC require DOB permits and must comply with the Zoning Resolution's setback, lot coverage, and open space requirements. In most residential districts, carports count as lot coverage and must meet side and rear yard setbacks. Building Code structural requirements apply.
New York City Carport Regulations
Some RestrictionsTiny Homes
Tiny homes face significant regulatory barriers in NYC. The Building Code sets minimum room sizes (120 sq ft for a living room, 80 sq ft for a bedroom). The Zoning Resolution generally does not permit standalone dwelling units on lots zoned for single-family use. Tiny homes on wheels are classified as vehicles and cannot serve as permanent dwellings.
New York City Tiny Home Regulations
Heavy RestrictionsLooking for New York County county-wide rules?
County ordinances apply to unincorporated areas and may supplement New York city rules.
Accessory Structures in New York County →