New Haven, CT Accessory Structures: ADU Impact Fees (2026)

Connecticut municipalities derive their powers from the General Statutes, and the General Assembly has not enacted a development impact fee enabling statute. Connecticut courts have repeatedly held that municipal exactions on development must rest on specific statutory authority — subdivision improvements under CGS Section 8-25, sewer connection charges under CGS Section 7-255, water connection charges under utility enabling legislation — and cannot rest on general police powers alone. For an ADU project in New Haven, the fee structure includes: (1) a zoning compliance review fee through the City Plan Department (typically in the low hundreds of dollars depending on whether site-plan review is triggered); (2) building permit fees calculated on construction valuation under the New Haven fee schedule, with CGS Section 29-263 supplying the underlying authority for municipal building permit fees; (3) separate electrical, plumbing, and mechanical permit fees; (4) plan review fees; (5) a state education surcharge under CGS Section 29-263a (a small percentage of permit fees flowing to the state's school construction account); (6) Regional Water Authority (RWA) tap fees if a new water service is installed, with sharing of the existing principal-dwelling service typically avoiding the new-service charge; (7) Greater New Haven Water Pollution Control Authority (GNHWPCA) sewer connection charges if a new lateral is installed under CGS Section 7-255; (8) New Haven Land Records recording fees for any easements or covenants. New Haven Public Schools is funded through the state Education Cost Sharing formula and city general-fund appropriations; Connecticut does not authorize school impact fees on new construction. Property taxes (New Haven's mill rate is one of the higher in the state) on the increased assessed value after construction provide the long-term revenue stream rather than an upfront impact fee.