Accessory dwelling unit permit cost — New Haven, CT
Last updated: September 24, 2026
What affects the price
Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.
Frequently asked in New Haven
What's involved with prefab ADU options in New Haven?
How can I get help with accessory dwelling unit services in New Haven?
What should I expect for an ADU estimate in New Haven?
What does 'accessory dwelling unit' actually mean for a New Haven homeowner?
For a New Haven homeowner, an accessory dwelling unit (ADU) means a second, independent living unit on your existing residential property. It has its own kitchen, bathroom, and sleeping area. Think of it as a compact, self-contained home within your backyard or attached to your main house. It's a flexible way to add housing for family, renters, or guests right here in New Haven.
How do I find a reliable ADU company in New Haven?
Are there accessory dwelling unit grants available in Connecticut?
What makes an accessory dwelling unit the 'best' for my New Haven property?
Also serving nearby: Bridgeport · Waterbury · Norwalk · Hartford · Stamford
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of New Haven — population 135,319; about 7,240 residents per square mile across 18.7 sq mi. ZIP codes covered include 06501, 06502, 06503, 06504, 06505, 06506, 06507, 06508.
Neighborhoods served in New Haven: Wooster Square, East Rock, The Hill, Downtown New Haven, Newhallville — and every surrounding area.
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