Across 177 permits filed since 2025-05-02, the median is $10,500; half of projects fall between $4,200 and $60,000. 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 Hartford County, CT actually reported when they pulled permits.
Recent filings
- ****JIM IS ASSIGNED TO THIS**** Extending the living room area off of the back of the home. 25X13 addition. CA fee includedTown of Southington · 2026-10-26$75,000
- addition in back 12'6X42'6 add second story to the house and garage 30'X36'Town of Southington · 2026-10-23$342,000
- Provide electrical wiring, install receptacles, switches and lights in the addition Your application for a Building Permit has been reviewed for compliance with the 2022 State of Connecticut Building Code. The permit for the proposed work iSimsbury · 2026-10-23$2,500
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 Hartford County, CT came in between $4,200 and $60,000. 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
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