Two categories of HVAC work generate a disproportionate share of the unpermitted-work violations we resolve every month: ductless mini split installations, and central AC replacements — condensers, air handlers, or full swap-outs. Both are governed by the same section of the Florida Building Code, both require a mechanical permit (and usually an electrical one), and both are routinely done in Miami-Dade and Broward without either.
The pattern is consistent. A homeowner's central AC dies on a Friday afternoon. The unit is 15 years old, R-22 refrigerant, and it's 92°F outside. A neighbor recommends a handyman who "does this stuff all the time" and can have a replacement in by Monday for cash. No permit is pulled. Two years later, the property goes under contract, a four-point inspection is ordered, and the inspector flags the newer condenser sitting next to the original disconnect and pad — which don't match the permit record. What was a $5,000 emergency replacement now blocks a $600,000 closing until the after-the-fact permit is filed and inspected.
The mini split version of the same story is different in the mechanism but identical in the outcome. A homeowner adds a ductless head to a converted garage, a backyard office, or a second-floor bedroom that never had adequate cooling. Two zones, one outdoor condenser, quick weekend install by someone the homeowner found on Facebook. No permit. The system runs fine — until it's discovered during a recertification, an insurance carrier's site visit, or a code-enforcement complaint. At that point, a $3,500 install becomes a code-enforcement matter.
This article walks through what actually requires a permit under Florida and Miami-Dade code, why the permit is so often skipped, how these violations get discovered years after the fact, and the after-the-fact mechanical permit pathway that closes them out.
What actually requires a permit
Under the Florida Building Code, Mechanical (FBC-M) and Miami-Dade County's permit requirements, essentially any installation, alteration, replacement, or relocation of mechanical HVAC equipment requires a permit. The rule is broader than most homeowners realize — and broader than many handymen will admit.
Central AC replacement — even like-for-like
Replacing a central AC condenser, air handler, or complete system requires a mechanical permit issued to a state-licensed HVAC contractor (Class A, B, or Registered). This is true even when the replacement is same-tonnage, same-location, and same-model-family as the original. The permit exists to verify that: the new equipment is properly sized for the load; the refrigerant line set is intact and correctly reconnected; the electrical disconnect is code-compliant for the new equipment's amperage; the condensate drain terminates correctly; the condenser is mounted on a hurricane-rated pad or bracket appropriate for Miami-Dade or Broward's High-Velocity Hurricane Zone (HVHZ); and any new penetrations through the building envelope are properly sealed and flashed.
A same-for-same swap that skips these verifications may work fine mechanically but will fail inspection when the property is scrutinized. And in HVHZ, an improperly mounted condenser is not just a paperwork problem — it's a projectile risk in a hurricane, which is why the mounting standards exist in the first place.
Mini split installations — every one of them
Ductless mini splits require a mechanical permit for the equipment installation and, in almost every case, an electrical permit for the dedicated circuit that feeds the outdoor condenser unit. Single-zone systems, multi-zone systems, DIY-branded kits from big-box retailers or Amazon — all of them require permits when installed in a residential property in Miami-Dade or Broward. The Florida Building Code does not carve out an exception for "small" HVAC equipment. It does not carve one out for "temporary" installations. And it certainly does not carve one out for owner-installed systems.
The specific permit trigger for mini splits usually includes: the mechanical permit for the equipment and refrigerant line set; the electrical permit for the new circuit at the panel; and, if the line set penetrates the exterior wall, verification that the penetration is properly sealed to preserve the building envelope. In multi-story installations or in installations where the condenser is mounted at height on an exterior wall, an engineering letter may be required to confirm the bracket rating meets HVHZ wind loads.
What doesn't require a permit
Routine service is not a permit trigger. Recharging refrigerant on an existing system, replacing a capacitor, cleaning a coil, replacing a thermostat — none of that requires a permit. The permit line is drawn at installation, replacement, relocation, or alteration of the equipment itself or of the electrical, refrigerant, or condensate infrastructure feeding it. Anything a licensed HVAC technician would do as part of a service call rather than an install is generally on the service-only side of the line.
Why the permit gets skipped
The permit is skipped for a small set of predictable reasons, and being familiar with them helps homeowners recognize when they're on the wrong side of the line.
Emergency replacements. When a central AC dies during a South Florida summer, the pressure to get cooling back is enormous. Some HVAC companies will pull a next-day permit and start work under it; others — and, more commonly, informal installers — will simply skip the permit to move fast. The homeowner is rarely told either way. They see the equipment installed, they pay, they get a warranty card and a receipt. Whether a permit was pulled is not something most homeowners think to verify.
Cash-and-carry installers. A significant share of unpermitted HVAC work is done by handymen or unlicensed installers who cannot legally pull a mechanical permit because they don't hold the required state HVAC license. When the person installing your equipment cannot pull a permit, there is no permit — regardless of what they may tell you or imply. The only way to pull a mechanical permit is with a licensed HVAC contractor's information on the application.
DIY mini split kits. Big-box retailers and online marketplaces sell mini split kits marketed as "no professional installation required." These kits still legally require a permit. The Florida Building Code applies to the work being done on the property, not to who's doing it. A homeowner-installed mini split without a permit is still unpermitted work — and the fact that the equipment came from a legitimate retailer offers no defense.
Assumption that replacement doesn't need a permit. This is one of the most common false beliefs we hear: "I'm just replacing what was already there, so I don't need a new permit." That is not how the code works. A replacement is a new installation from the code's perspective, and the mechanical permit is required to confirm that the replacement equipment matches the existing electrical service, the line set, the disconnect, the pad, and the load calculations. Same-for-same replacement is a permit trigger, not a permit exemption.
How the violation surfaces — usually years later
Unpermitted HVAC work rarely triggers an immediate violation. The system runs, the house cools, and life continues. The violation surfaces during a specific set of downstream events — most of them involving a third party pulling records on the property.
Four-point inspections during resale or insurance renewal
Any Florida home over 25 years old is typically subject to a four-point inspection when the property is being sold, refinanced, or when a new insurance policy is being written. HVAC is one of the four points (along with roof, electrical, and plumbing). The four-point inspector will note the equipment's age, model, and installation. When the visible equipment doesn't match what appears in the permit record, the inspector flags it. That flag ends up in the underwriting file — where it can delay a closing, kill a refinance, or cause an insurance carrier to non-renew.
Forty-year recertification
Miami-Dade's building recertification process (30 years inland, 25 years for qualifying coastal buildings, and every 10 years thereafter under Section 8-11(f)) requires a licensed engineer or architect to verify structural and electrical safety on qualifying buildings. Unpermitted electrical work — including the dedicated circuit that feeds an unpermitted mini split condenser — routinely surfaces during this process. The recertification cannot be signed off until the unpermitted work is either legalized through an after-the-fact permit or removed.
Storm damage claims
An improperly mounted condenser that fails during a windstorm is not just a mechanical loss — it's an insurance claim that will get scrutinized. The carrier will pull the permit history. When no permit exists for the equipment, the claim may be denied on the grounds that the failed installation did not comply with the code in effect at the time of installation. Homeowners have learned this the expensive way after hurricanes.
Code-enforcement complaints
Miami-Dade and Broward code-enforcement officers do respond to complaints — typically from neighbors — about visible new equipment on properties. A new condenser mounted on the exterior wall or a new mini split head visible through a window can be enough to trigger a records pull and, if no permit is on file, a Notice of Violation.
The specialist's read
The pattern we see over and over: the work was done years ago by someone who is no longer in business, or whose license is no longer active, or whose paper trail cannot be reconstructed. The homeowner has no record of who did the install, no invoice showing whether a permit was pulled, and no way to prove after the fact that the equipment was properly installed to code. That's not a rare situation — it's the default situation for most unpermitted HVAC work older than three or four years.
The after-the-fact mechanical permit — how the violation gets resolved
Unpermitted HVAC work is legalizable through the same after-the-fact permit pathway we use for other categories of unpermitted construction. The procedural steps are the same as for any mechanical permit — with the addition of the after-the-fact designation, which triggers the "double fee" rule discussed in our working-without-a-permit guide. In practice, an after-the-fact mechanical permit for HVAC work looks like this:
- A licensed HVAC contractor is retained to sponsor the after-the-fact application. This is a legal requirement — a mechanical permit can only be applied for by a state-licensed HVAC contractor, and the after-the-fact designation does not change that requirement. The homeowner who installed the equipment personally still needs a licensed contractor to legalize it.
- The existing equipment is inspected by the contractor to verify it meets current code — proper equipment sizing for the load, correct refrigerant type and charge, correctly rated disconnect, properly mounted condenser (with HVHZ-rated pad or bracket), sealed line set penetrations, code-compliant condensate drain, and appropriate wire gauge and breaker sizing on the electrical side.
- Deficiencies are corrected before the permit inspection. This is often the biggest cost of an after-the-fact mechanical case — not the permit fee itself, but the correction work. A condenser mounted on unrated concrete blocks in HVHZ needs to be remounted on an NOA-rated pad or bracket. A disconnect that's not sized correctly for the equipment needs to be replaced. A line set penetration that was left unsealed needs to be flashed properly.
- The after-the-fact permit is filed with the appropriate municipality — Miami-Dade County, City of Miami, Coral Gables, Miami Beach, Doral, Homestead, Hialeah, Fort Lauderdale, Hollywood, or whichever jurisdiction the property falls in. Each has slightly different submission procedures.
- Plan review and field inspection follow the standard mechanical permit process. The inspector verifies the equipment against the code in effect at the time of inspection (not at the time of original install, which for after-the-fact permits works in the homeowner's favor since older code was often less stringent).
- Any corrections flagged by the inspector are addressed and re-inspected.
- The permit closes against the property record. From that point forward, the equipment is documented, permitted, and inspected — and it will not flag on future four-point inspections, recertifications, or title searches.
Typical timeline is 6 to 10 weeks for straightforward residential after-the-fact HVAC cases, depending on the municipality's review queue and whether corrections are needed. Cases involving multiple pieces of equipment or unusual mounting situations can run longer.
What it costs
The financial picture has three components:
- The mechanical permit fee itself — typically $150 to $450 for residential HVAC, depending on the municipality and the scope. If a Notice of Violation has already been issued, the double fee rule applies and this doubles.
- Correction work — the labor and materials to bring the existing installation up to current code. This is highly variable. A well-installed same-for-same replacement that just skipped the permit may need only minor corrections. A DIY mini split with an improperly mounted condenser, unsealed penetration, and an undersized breaker could run $1,500 to $4,000 in correction work.
- The licensed HVAC contractor's sponsorship fee — for retaining a licensed contractor to pull the permit and perform any correction work required. This varies by contractor and by scope.
Compared with the code-enforcement assessment that continues to accrue daily fines while an NOV is unresolved, and the transactional friction the unpermitted work creates on any future sale, refinance, or insurance renewal, the after-the-fact resolution is almost always the cheaper path.
How to check whether your HVAC equipment was permitted
Most homeowners cannot answer this question about their own property with certainty. If you bought the home from a previous owner, you may have no record of whether the AC condenser sitting on the pad outside was permitted when it was installed — and neither did the seller, in many cases. Pulling the record is the only way to find out.
The free MyHausFax™ Snapshot we produce as part of our intake process includes a full permit record pull for your property, cross-referenced against the visible equipment. If a permit exists for the current condenser and air handler, you're clean. If it doesn't, the report will flag the gap and identify the after-the-fact pathway. You'll have the information within one business day — with no obligation to engage further.
For property owners already dealing with an NOV or a flagged four-point inspection, the after-the-fact pathway is covered end-to-end by our Permit Violations service and, for the retroactive-permit mechanics specifically, our After-the-Fact Permits service. Both include the licensed HVAC contractor sponsorship required to legally file the mechanical permit.
Permit Solutions Services is a Miami-based specialist firm resolving permit violations, after-the-fact permits, open permits, and complex compliance cases across Miami-Dade and Broward counties — including the HVAC-driven violations covered in this article. For a free MyHausFax™ Snapshot of your property's compliance record, including a check of whether your HVAC equipment is on file, request one here or call 305-600-9422.