New Jersey ADU Rules — No Statewide Mandate, Municipal Authority Under MLUL

Under New Jersey's Municipal Land Use Law (N.J.S.A. 40:55D-1 et seq.), zoning power is delegated to each of the 564 municipalities — counties have no zoning role except for review of subdivisions affecting county roads or drainage. As of May 2026, New Jersey is one of the few coastal-Northeast states WITHOUT a statewide ADU preemption like California (Gov. Code §65852.2), Vermont (24 V.S.A. §4412(1)(E)), or Massachusetts (M.G.L. Ch. 40A §3A). The legislative history: Senate Bill S2347 was introduced January 29, 2024 by Senator Troy Singleton (D-Burlington) to authorize ADUs as of right in single-family and two-family zones, limit parking requirements to one space (waived near transit), and impose a 60-day ministerial review window. S2347 did not advance past committee in the 2024-2025 session and expired. Senator Singleton reintroduced substantially similar provisions as S1786 in the 2026-2027 session (introduced January 13, 2026), which is pending in the Senate Community and Urban Affairs Committee. The New Jersey League of Municipalities has formally opposed statewide ADU preemption. Several New Jersey municipalities have voluntarily adopted ADU-friendly ordinances — including Jersey City (Land Development Ordinance §345-41 allows detached ADUs), Montclair (March 2023, 300-800 sq ft with owner-occupancy and recorded deed notice), and South Orange Village (2023). Newark's Title XLI (adopted November 2023) treats any indoor space of 250+ sq ft with separate access as an additional dwelling unit. Most other New Jersey municipalities either prohibit or significantly restrict ADUs through their underlying zoning. Construction permits are issued by each municipality's Construction Official under the New Jersey Uniform Construction Code (N.J.A.C. 5:23).