Across 434 permits filed since 2025-01-25, the median is $15,000; half of projects fall between $10,000 and $23,395. 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 Nassau County, NY actually reported when they pulled permits.
Recent filings
- Residential Air Conditioning - Install replacement central air conditioning systemVillage of Garden City · 2026-07-24$13,900
- Residential Air Conditioning - Install one (1) zone 4-ton central air conditioning cooling/heating systemVillage of Garden City · 2026-07-24$14,000
- Residential Air Conditioning - Install direct replacement central air conditioning unitVillage of Garden City · 2026-07-24$11,500
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 hvac / central air permits in Nassau County, NY came in between $10,000 and $23,395. 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
HVAC / central air in New JerseyHVAC / central air in New YorkHVAC / central air in ConnecticutHVAC / central air on Long Island