ADU rules in Jersey City

Accessory Dwelling Units are a permitted accessory use in the RH-1, RH-2, R-1, and R-2 zoning districts: one dwelling unit is permitted in an accessory structure per lot regardless of lot size, in addition to the unit(s) in the principal structure. The Chapter 345 definition (added 10-13-2022 by Ord. No. 22-084) describes an ADU as a single-unit dwelling in an accessory structure that is detached from the principal building.

By definition an ADU must be in an accessory structure detached from the principal building, so attached or internal ADUs are not permitted as ADUs. The city's own guide states all ADUs must be detached and that converting an attached or ground floor garage is not an ADU. In the R-1 district only, adaptive reuse of a garage as a dwelling unit is a separate conditional use requiring Planning Board approval, with conditions including removal of the driveway and curb cut and a cap of three units in the principal structure.

The zoning districts set no floor area limit for ADUs; the city guide confirms there is no limit on ADU square footage. RH-1 caps accessory building height at 18 feet if an ADU; RH-2, R-1, and R-2 cap ADUs at 18 feet and two stories, versus 12 to 15 feet for other accessory structures. R-1 raises maximum permitted lot coverage by an additional 5% when an ADU is proposed or present.

No owner occupancy requirement is attached to ADUs in the RH-1, RH-2, R-1, or R-2 district regulations or the ADU definition. Owner occupancy rules appear only in unrelated contexts: the Affordable Housing Overlay fee waiver and the short-term rental ordinance.

RH-1, RH-2, and R-1 each state that Accessory Dwelling Units are exempt from any minimum parking requirement in the zone. The R-2 parking standards contain no ADU exemption, and the city guide likewise says to follow R-2 minimum parking requirements there. Several districts also prohibit off-street parking entirely on narrow lots.

ADUs are listed among permitted accessory uses in the RH-1, RH-2, R-1, and R-2 districts, so a complying detached ADU needs only standard zoning and construction permits, not a use variance or conditional use approval. Conditional use approval is required only for the separate R-1 attached or ground floor garage conversion path.

Chapter 255 (added 6-25-2019 by Ord. No. 19-077) defines an STR as accessory use of a dwelling unit for 28 or fewer consecutive days and limits STRs to listed classifications, including owner-occupied single-family residences, two-family dwellings with one owner-occupied unit, and small multiple dwellings with an owner-occupied unit. Owner-not-present rentals are limited to 60 total nights per year and prohibited in multiple dwellings with more than four units. Renting an ADU short-term would have to fit one of these classifications and permit requirements.