Unpermitted HVAC Work and Home Sale Disclosure in California: What Sellers and Contractors Need to Know

The call usually comes about four weeks before close of escrow. The home inspector flagged the furnace, the appraiser noted a recent condenser swap, and somewhere in the listing paperwork there is a question the seller does not know how to answer: was this permitted? In California, that question is not optional and the wrong answer can unwind the sale months after closing.

This is a practical guide for homeowners getting ready to list and for HVAC contractors who get pulled into the conversation when their phone rings on a Tuesday afternoon. The rules are clearer than people assume, and the path to closing the deal is almost always the same: disclose, quantify, and decide whether to permit before or after escrow.

California Disclosure Law Is Not Subtle

California Civil Code section 1102 requires every residential seller to deliver a Transfer Disclosure Statement. The TDS asks specifically about additions, alterations, or repairs made without necessary permits and final inspections. Unpermitted HVAC work is almost always a material fact under California case law, which means a reasonable buyer would consider it when deciding whether to buy or what to pay. Hiding it is fraud, not negligence, and the statute of limitations on a fraud claim is three years from discovery.

The legal exposure is real. Buyers have successfully rescinded sales years after closing on the basis of undisclosed unpermitted work. They have also won damages equal to the cost of bringing the work up to code, plus loss of use, plus attorney's fees. The cost of telling the truth on the TDS is almost always lower than the cost of being caught not telling it.

How Buyers Find Out

They find out almost every time. Three pipelines surface unpermitted HVAC work during a normal California real estate transaction:

The home inspector spots a condenser, furnace, or air handler that looks newer than the rest of the system, notices a serial number that postdates the last permit on file, or sees workmanship that does not match what a permitted job would look like (no service disconnect, missing condensate trap, undersized flue). The inspection report goes to the buyer and the buyer's agent, who will ask.

The appraiser pulls the permit history from the city's online portal. Most Bay Area jurisdictions publish permit history publicly. When the appraiser sees a 2018 condenser on the roof and no permit since 2009, that goes in the appraisal report.

The buyer pulls the permit history themselves. This has gotten common since most permit portals are now accessible without a login, and a buyer who is paying $1.4M for a house in San Mateo spends the twenty minutes to check.

The Lender Problem

Conventional loans sometimes ignore unpermitted work if the appraisal does not call it out as a health and safety issue. FHA and VA loans are different. Both have explicit minimum property standards that require all systems to be installed in accordance with applicable codes, and the underwriter will read the appraisal. If the appraiser flagged the unpermitted condenser, the loan does not fund until the issue is resolved.

"Resolved" usually means one of three things: the work gets retroactively permitted and passes inspection, the work gets removed and replaced with a permitted install, or the parties agree to an escrow holdback that funds the retroactive permit after closing. Holdbacks are the most common path because they let the deal close on schedule, but the buyer's lender has to approve the holdback structure before it works.

Retroactive Permits: How They Actually Work

California building departments allow after-the-fact permits for almost all HVAC work. The application process is the same as a normal permit, with three differences. The fee is doubled as an investigation penalty. The inspector requires physical access to verify the installation, which often means opening drywall to expose ducts or pulling the furnace cabinet apart. And a licensed HVAC contractor usually has to be the applicant of record because the homeowner cannot certify that the work meets code if they did not perform it.

The corrections list is usually the painful part. An install done in 2018 was code-compliant in 2018, but the inspector is checking it against the current Title 24 requirements. Refrigerant lines that were fine then may need additional insulation now. The disconnect that was acceptable then may need to move. HERS testing is almost always required even when the original install never had it. Plan on a correction or two and budget the time.

For the full walkthrough of a clean filing, see how to pull an HVAC permit in California. A retroactive permit follows the same flow with the penalty fee on top.

What It Costs in the Bay Area

Permit fees doubled puts the city portion at roughly $500 to $1,400 across most Bay Area jurisdictions. San Francisco DBI is on the higher end because the base fee is higher to start, and Oakland adds an additional code enforcement surcharge on retroactive applications. Add HERS verification ($150 to $300), contractor labor to expose work for the inspector ($300 to $1,500 depending on access), and potential correction work if the install does not meet current code. All-in, plan for $1,500 to $4,000 for a retroactive HVAC permit. We did the city-by-city breakdown of base fees in HVAC permit costs in the Bay Area.

Permit Before Listing or Negotiate Through Escrow?

The decision is usually about timing, leverage, and the seller's appetite for hassle. Permitting before listing eliminates the issue from the negotiation, lets the seller market a clean property, and avoids the lender holdback dance. The downsides are time (4 to 8 weeks in most Bay Area cities) and the chance that corrections turn up that the seller now has to fund before listing.

Negotiating through escrow keeps the listing moving but hands the buyer leverage. A buyer who learns about unpermitted work mid-escrow will almost always ask for a price reduction larger than the actual cost to permit, because the discovery itself made them nervous about whatever else might be wrong. Sellers who can afford the time before listing usually come out ahead by just permitting first.

For Contractors: This Is a Real Service Line

If you work in any urban California market, retroactive permits before close of escrow are a steady source of work. The lead comes through the listing agent, the homeowner, or sometimes directly from the buyer. The job is usually small (no install) but the timeline is tight and the client is motivated. Three things to get right:

Set expectations on timeline before you accept the job. A retroactive permit in San Francisco takes longer than one in Sunnyvale, and if escrow closes in three weeks you need to say so up front. Charge appropriately for the inspector access work. The cabinet pulls and ceiling cuts are the most labor-intensive part and homeowners do not understand why a permit costs more than the installation did. Document everything for the disclosure file. The seller's agent wants a clean paper trail to attach to the supplemental TDS.

The mistakes that catch contractors here are the same ones from regular permit filing, just with a tighter deadline.

What If the Sale Already Closed?

If a buyer discovers unpermitted HVAC work after closing and disclosure was not made, they have real recourse. The most common outcome is a settlement where the seller pays for retroactive permitting plus a negotiated amount for the inconvenience and the diminution in value. Cases that go to court occasionally rescind the sale entirely. The cleanest path forward, even post-close, is to retroactively permit the work and document the resolution. It does not undo the disclosure failure but it caps the damages at something quantifiable.