Across 28 permits filed since 2025-05-02, the median is $15,500; half of projects fall between $3,150 and $131,152. Figures are permit valuations reported to building departments. National cost guides answer this question with averages from other markets; these numbers are what homeowners in New Haven, CT actually reported when they pulled permits.
Recent filings
- REAR ADDITION Interior reorganization of walls CA 1 FAMILY B-77134 10/10/68City of New Haven · 2026-10-29$90,000
- 10000 sf tenant fit out on 2nd floor of 101 college st. includes new partitions, acoustical ceilings, flooring, painting lab casework and associated infrastructure, extension of base building M/E/P systems, sprinkler relocations, new lightiCity of New Haven · 2026-10-13$877,000
- Complete interior non-structural gut (DEMOLITION ONLY - Per John Connors, Standard Builders 9/30/2026). Work includes removal of internal non-bearing partitions, finishes, ceilings, and MEP systems. Existing structural frame, foundation, beCity of New Haven · 2026-10-13$331,374
How to read these numbers
Permit valuations are the project cost the applicant reports to the building department. They skew slightly low — nobody rounds up for the permit fee — and scope varies, so the middle-half range is the honest picture: half of all home addition permits in New Haven, CT came in between $3,150 and $131,152. We exclude permits under $1,000, jobs filed as whole-house construction, and counties whose building departments don't reliably report valuations.
Same project, other places
Home addition in New JerseyHome addition in New YorkHome addition in ConnecticutHome addition on Long Island