This covers folio numbers starting with 30. The City of Miami, Hialeah, Coral Gables and the other cities run their own permit offices.
What needs a permit and what does not
From the county's Permit Exemptions page (read 24 October 2026):
| Work | Permit? |
|---|---|
| AC change-out with the same electrical amperage | Mechanical permit yes; electrical permit no |
| Repair by a licensed mechanical contractor, $500 or less | No |
| Repair of AC duct (licensed contractor) | No |
| Replacing a coil, compressor or refrigerant piping inside the equipment (licensed AC or mechanical contractor) | No |
| Replacing fans inside equipment | No |
| Replacing a window AC unit; installing a ductless range hood (house, duplex, townhouse) | No |
| A new system, added tonnage, new ductwork, a relocated condenser | Yes |
The county's small-project exemption under Florida House Bill 803 (from 1 July 2026, under $7,500) lists "Mechanical work" among the work that always needs a permit.
Who can pull it. Licensed contractors or owner-builders (How to Apply). The county's owner-builder page names mechanical among the trade permits an owner-builder may take out, for a one- or two-family home the owner occupies, after an owner-builder validation. An AC company should pull its own.
What it costs
From Implementing Order 4-63 (effective 1 October 2026):
| Item | Fee |
|---|---|
| Exact change-out of a central AC unit including heating, existing home (residential hardening pilot) | $133.38 flat |
| AC and refrigeration, including relocating equipment, per ton | $24.80 |
| Furnaces and heating equipment, per kW | $4.97 |
| AC duct work, per sq ft of conditioned space up to 3,000 sq ft | $0.11 |
| Minimum mechanical permit, single-family and duplex | $150.82 |
| Additional inspection beyond the initial and one follow-up | $94.88 |
| Work started before the permit | 100% extra |
On the per-ton rate a 3-ton system would be $74.40, so the $150.82 minimum applies; an exact change-out on an existing home is the $133.38 flat fee instead. Separate permits are needed for any electrical, water or gas connections. A 7.5% RER surcharge and the state surcharges are added.
A Notice of Commencement, required on jobs over $5,000, is not required "for repair or replacement of an existing heating or A/C system valued under $15,000" (How to Apply, read 24 October 2026).
How to apply and get it inspected
- Confirm the folio starts with 30.
- Apply. Contractors can file mechanical permits that need no plan review through the county's e-permitting system; work with plans goes through the EPS portal.
- Inspections. Book through the Building Permit Selection Menu or at 786-315-2100 by 4 p.m. the business day before; inspectors work 8 a.m. to 3:30 p.m. weekdays (Inspections). For a raised roof-mounted unit the county offers on-demand rough inspections.
What 10,248 HVAC permits show
| Measure | Unincorporated Miami-Dade HVAC |
|---|---|
| Permits, November 2024 to September 2026 | 10,248 (9% of all county permits) |
| Last 12 months (October 2025 to September 2026) | 5,415 |
| Homes | 46% |
| Usual declared value | $20,000 (middle half $4,580 to $127,688) |
| Busiest / quietest month | October (124) / February (82) |
| ZIPs with the most | 33176 (861), 33175 (460), 33186 (448) |
| County permit type | Permits | Share |
|---|---|---|
| A/C - Unltd | 8,190 | 80% |
| Sheet metal (ductwork) | 501 | 5% |
| Mechanical ventilation | 418 | 4% |
| Heating | 291 | 3% |
| Raise existing roof-mounted equipment | 152 | 1% |
Fewer than half of HVAC permits are on homes, so the usual value and its wide middle half mix in commercial systems. Filing climbs through the summer and peaks in October, after the hottest months; February is the quietest. 33176 has almost twice the permits of the next ZIP. Monthly counts and the contractors named most often are on Miami-Dade HVAC permits; see also Miami-Dade permit statistics and browse Miami-Dade permits.
Before you hire
Check the AC company's earlier county permits with Contractor Permit Inquiry (Miami-Dade building permit search) and its state license (how to check a contractor's license in Florida). Other places' rules: do I need a permit to replace my furnace or AC; filed values elsewhere in HVAC replacement cost.
What this does not tell you
The county's file has no status and no final date, so we cannot say how many AC permits passed final or how long they took, and it starts in November 2024, so there is no earlier year. 18% of HVAC permits carry no declared value. The file does not say a system's tonnage or whether it is a heat pump.
How we know this
Exemptions are quoted from Miami-Dade County's Permit Exemptions page, fees from Implementing Order 4-63 (effective 1 October 2026), and the owner-builder, Notice of Commencement and inspection rules from the county's Owner-Builder Permits, How to Apply and Inspections pages, all read 24 October 2026. Our counts are the county's Building Permits Issued By Miami-Dade County layer, read 20 October 2026: mechanical permits issued November 2024 to September 2026 on parcels whose folio starts with 30.
Numbers come from public permit records in 57 cities, data through October 20, 2026. Nobody paid to be on this page and nobody can.
Questions
- Do I need a permit to replace my AC in Miami-Dade County?
Yes, in unincorporated Miami-Dade. The county says a change-out of AC equipment with the same electrical amperage needs no electrical permit, but a mechanical permit is required.
- How much is an AC permit in unincorporated Miami-Dade?
An exact change-out of a central AC unit, heating included, on an existing home is a flat $133.38 under the county's residential hardening pilot. Otherwise AC and refrigeration is $24.80 per ton with a $150.82 minimum, plus a 7.5% surcharge.
- What AC repairs do not need a permit in Miami-Dade?
Repairs by a licensed mechanical contractor of $500 or less, duct repairs, and replacing a coil, compressor, refrigerant piping or fans inside the equipment. Replacing a window AC unit in a house, duplex or townhouse is also exempt.
- Do I need a Notice of Commencement for an AC replacement in Miami-Dade?
Not if the repair or replacement of an existing heating or AC system is valued under $15,000; above that, the county's $5,000 Notice of Commencement rule applies.
- When do people file the most AC permits in Miami-Dade?
October, at 124 against an average month of 100, followed by July (120); February is the quietest at 82.
Build your own list
Pick your city and the kind of work. Every firm with a permit on record, sorted by what you value.
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- Permit Exemptions — Miami-Dade County Regulatory and Economic Resources (2026-10-24)
- Implementing Order 4-63, Building Fee Schedule (effective 1 October 2026) — Miami-Dade County (2026-10-24)
- Owner-Builder Permits — Miami-Dade County Building (2026-10-24)
- How to Apply for a Permit — Miami-Dade County Building (2026-10-24)
- Inspections — Miami-Dade County Building (2026-10-24)
- Building Permits Issued By Miami-Dade County - 2 Previous Years to Present (ArcGIS layer) (2026-10-20)