East Orange, NJ Accessory Structures: ADU Rules (2026)

East Orange's R-1 District zoning, § 51-92, lists an accessory dwelling unit in an accessory building among the conditional uses available in the single-family district alongside public and private schools and houses of worship. Because it is conditional rather than permitted-by-right, an applicant must obtain Planning Board approval and meet the standards for conditional uses contained in Article XXIII, § 51-118, before building or converting an accessory structure into a dwelling unit. The ordinance caps the unit's size at not more than 25% of the principal building, not counting the cellar, tying the accessory dwelling's footprint to the size of the main house rather than to a flat square-footage number.

Because the unit sits inside an accessory building, it must also satisfy the general accessory-building rules that apply citywide under § 51-89 and the R-1-specific accessory-building standards under § 51-92D(1): a 400-square-foot rear-yard size cap, rear-yard-only placement, height no taller than the principal structure, no more than 50% of the principal building's floor area, a 40-foot front setback, and a three-foot setback from every lot line. Sequencing rules bar construction of the accessory unit before work on the main house has begun and bar its use before the main house is completed and occupied. Owners route the necessary construction permit through the zoning-permit prerequisite in § 51-59, administered by the Zoning Officer and the Department of Property Maintenance.