New Haven County, CT Accessory Structures: ADU Rules (2026)

Connecticut counties have had no operational government since the County Manager Act was repealed in 1960. New Haven County land-use authority rests entirely with the individual municipalities. The metropolitan region is divided between two of the state's nine planning regions: the South Central Regional Council of Governments (SCRCOG), comprising Bethany, Branford, East Haven, Guilford, Hamden, Madison, Meriden, Milford, New Haven, North Branford, North Haven, Orange, Wallingford, West Haven, and Woodbridge; and the Naugatuck Valley Council of Governments (NVCOG), which includes Waterbury, Ansonia, Beacon Falls, Cheshire, Derby, Middlebury, Naugatuck, Oxford, Prospect, Seymour, Shelton, Southbury, Thomaston, Watertown, Wolcott, and Woodbury (the NVCOG region also extends into parts of Litchfield and Hartford counties). The state framework is Conn. Gen. Stat. Sec. 8-2, the zoning enabling act, as amended by Public Act 21-29 (HB 6107) in 2021. PA 21-29 requires towns that zone under Sec. 8-2 to permit ADUs as of right on the same lot as single-family homes (without a variance, special permit, or public hearing) unless the town has affirmatively opted out by a two-thirds vote. ADUs created or permitted after January 1, 2023 that lack affordable-housing deed restrictions do not increase a municipality's base housing stock for the affordable-housing percentage under Conn. Gen. Stat. Sec. 8-30g. New Haven County town practice varies: New Haven and several SCRCOG members align with the as-of-right standard, while some smaller towns have invoked the opt-out. Applicants must consult the specific town's planning and zoning office.