New York, NY Accessory Structures: Garage Conversions (2026)

Converting a garage into living space in New York City is now regulated as the creation of an ancillary dwelling unit (ADU) under the City of Yes for Housing Opportunity zoning text amendment (adopted December 5, 2024) and Building Code Appendix U (added by Local Law 127 of 2024). An ADU is capped at 800 square feet of floor area, with one ADU permitted per single- or two-family residence (Zoning Resolution Section 12-10). A legally existing attached garage, a garage within the primary home, or a detached garage may be converted, and accessory off-street parking may be omitted where permitted by the Zoning Resolution. When an existing garage is converted, non-compliant setbacks of the original structure can generally be retained. A converted detached garage is treated as a detached ADU: under Appendix U it must be sprinklered and is classified as Group R-3 occupancy, and bulk rules limit a detached building containing an ADU to two stories or 25 feet (whichever is less), a footprint not exceeding one-third of the rear yard, a minimum five-foot setback from rear and side lot lines when free-standing, and a 10-foot minimum distance from the primary residence. Conversions that create habitable space below grade must meet Appendix U ceiling-height and flood-zone rules. Prior to City of Yes, garage-to-apartment conversions in much of NYC were prohibited or required a variance; the new framework makes many conversions permitted as-of-right.