Bayonne, NJ Accessory Structures: ADU Rules (2026)

City Code § 35-4.12, adopted under Ord. No. O-95-12, governs accessory buildings and structures citywide and draws a hard line against residential use of them. In residential districts, § 35-4.12.a.5 states that no accessory building structure or part of one shall be used for dwelling purposes, immediately after the section's other residential standards on coverage, three-foot setbacks, corner sight distance, and the requirement that a principal building already exist on the lot. The nonresidential districts subsection mirrors that ban: § 35-4.12.b.4 states no accessory structure shall be designed for dwelling purposes, on top of nonresidential-only rules barring accessory buildings from a required yard setback and requiring corner-lot accessory buildings to sit no closer than the building line of the adjacent principal structure.

Read together, the two clauses close off both an as-built conversion (residential 'used for') and a from-the-start design (nonresidential 'designed for') as ways to create a habitable accessory dwelling. Anyone wanting a second dwelling unit on a Bayonne residential lot instead runs into § 35-4.11, which bars more than one principal building on an R-1, R-2 or R-3 lot, and § 35-4.16, which allows a basement apartment only within the principal structure and only if its floor is no more than three feet below grade.