First Step: Find Out If the Work Was Actually Unpermitted
Before assuming no permit was pulled, verify it. Call your local building department with your address and ask for permit records. Many homeowners discover the permit was pulled — they just never got a copy. This 5-minute call saves unnecessary stress.
The Retroactive Permit Process
Retroactive (or "after-the-fact") HVAC permits are standard practice at most building departments. The process is essentially identical to a standard permit, with two key differences: the work is already done, and you may pay a higher fee.
- Contact your building department
Call your local building department (not the state), explain that HVAC work was completed without a permit, and ask about their retroactive permitting process. Most departments have a straightforward procedure. Bring: property address, date of installation if known, contractor name if known, equipment make and model.
- Submit a permit application for the existing work
The application is the same as a standard HVAC permit — describe the equipment and work that was done. If you don't have the equipment details, the model and serial number are on the data plate attached to both the indoor and outdoor units.
- Pay the fee (expect a penalty surcharge)
Most jurisdictions charge a penalty for retroactive permits — commonly 2x the standard permit fee. Boone County KY doubles the fee for installations where the permit wasn't obtained by the next business day. Other jurisdictions apply the penalty to any after-the-fact application regardless of timing. Budget for 2–3x the standard fee.
- Schedule an as-installed inspection
An inspector will examine the work as it currently exists. They will check the same items as a standard final inspection. Do not cover or conceal anything before the inspection — the inspector needs to see the installation.
- Correct any deficiencies and pass re-inspection
If the work doesn't meet current code, you'll need to correct the issues before the permit can close. This is where retroactive permitting can get expensive — especially if the work was done years ago to an older standard, or if problems are hidden behind walls.
Who Should Apply — You or the Original Contractor?
The original contractor is the right first call. Send them a written request (email creates a paper trail) asking them to obtain the retroactive permit. A licensed contractor who did unpermitted work is arguably in violation of their license — they have motivation to resolve this quietly. If they cooperate, they handle the application and are responsible for any inspection corrections.
If the original contractor is unresponsive, out of business, or unlicensed, you have two options:
- Apply yourself — if your state allows homeowner permits. You'll need equipment details and will be responsible for any code corrections.
- Hire a new licensed contractor — they apply for the retroactive permit, inspect the existing work, and take responsibility for bringing it to code. This is usually the cleanest solution for a real estate transaction.
Retroactive Permits in Real Estate Transactions
The most common scenario for retroactive HVAC permits is a home sale where the pre-sale inspection flags unpermitted work. Time pressure makes this more complex. Typical resolutions:
- Seller obtains retroactive permit before closing: Cleanest resolution. Requires quick turnaround — permit applications and inspections can often be expedited when a real estate transaction is involved.
- Escrow holdback: Funds are held in escrow until the permit is obtained and closed post-sale. Buyer and seller agree on a holdback amount that covers the permit cost plus potential correction costs.
- Price reduction: Seller reduces the price by an agreed amount representing the cost to resolve the permit issue. Buyer obtains the permit after closing.