Across 56 permits filed since 2025-05-02, the median is $15,500; half of projects fall between $6,800 and $54,250. 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 White Plains, NY actually reported when they pulled permits.
Recent filings
- Legalization of finished basement with new casement egress window, egress well and insulation.White Plains · 2026-10-09$14,500
- Construct a first floor one (1) story addition (18'-6" x 29'-6") to include a full unfinished basement storage below at garage grade with single side-door walk-out.White Plains · 2026-10-07$150,000
- ** Legalization ** Provide new wiring for lighting, switching, bathroom exhaust fan, ERV, heat pump, wall heater and TV in finished basement.White Plains · 2026-08-05$8,000
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 basement finishing permits in White Plains, NY came in between $6,800 and $54,250. 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
Basement finishing in New YorkBasement finishing in ConnecticutBasement finishing on Long Island