September 14, 2026
California's Title 24 energy code affects every HVAC replacement in Santa Clara County. Here's what the compliance process actually looks like — and what to ask your contractor before work begins.
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Most homeowners in Santa Clara County replacing an HVAC system are focused on one thing: getting the new system in and working fast. What they don’t always expect is that the moment a permit gets pulled — which it should — a compliance process kicks in that most contractors never bother to explain upfront.
California’s Title 24 energy code isn’t a technicality you can skip. It applies to every permitted HVAC replacement in Santa Clara County, and the requirements go well beyond just buying an efficient unit. If you’re in the middle of this process, or about to start it, here’s what you actually need to know.
Title 24, Part 6 of the California Building Code, sets the energy efficiency standards for residential and commercial buildings statewide. When it comes to HVAC, it covers a lot more than just the equipment you’re installing. Efficiency ratings, duct leakage, load calculations, thermostat controls, and third-party field verification all fall under its umbrella.
As of 2023, California requires a minimum efficiency rating of SEER 15 (or 15.2 SEER2) for most residential air conditioning systems. That’s the floor — not a premium upgrade. But meeting that standard alone doesn’t mean your project is compliant. The ductwork, the sizing method, and the verification process all have to check out too.
What surprises most homeowners is that Title 24 compliance isn’t something you confirm at the end. It’s built into the permit and inspection process from the start, which means your contractor needs to know what they’re doing before the first part gets ordered.
Here’s something most people in Santa Clara County don’t know: for years, the county was exempt from California’s duct pressure testing requirements. Those requirements were introduced statewide in 2006, but Santa Clara County had an exemption that kept them off the table for local projects. That exemption has since been removed. Every county in California — including Santa Clara — now requires duct pressure testing as part of a Title 24-compliant HVAC replacement.
What that means practically is this: if your ducts are leaking more than the code allows, your project won’t pass inspection, even if the new equipment is brand new and fully efficient. For replacements that include new ductwork, the leakage threshold is 6% or less. For replacements where the existing ducts stay in place, the threshold is 15% or less.
Those numbers sound manageable until you consider what PG&E estimates about the average California home: duct leakage typically runs between 30% and 40%. That’s not a worst-case figure — it’s the average. Homes built in the 1960s through the 1980s, which make up a significant portion of the housing stock in neighborhoods across San Jose, Sunnyvale, and Santa Clara, are especially likely to have duct systems that are well past their functional life and nowhere near compliant.
If your contractor isn’t asking about your ductwork before quoting your replacement, that’s worth paying attention to. A compliant installation accounts for the duct system — not just the equipment sitting in your garage that needs to be swapped out.
One of the most confusing parts of the Title 24 process for homeowners is the paperwork. There are three compliance documents involved in a permitted HVAC replacement, and each one has a specific owner and a specific timing requirement. If your contractor hasn’t mentioned these, it’s a gap worth closing before work starts.
The first is the Certificate of Compliance, known as the CF1R. This is prepared by your HVAC contractor before installation begins and requires the building permit to be in place first. It documents how the project is designed to meet Title 24 requirements.
The second is the Certificate of Installation, the CF2R. This is completed by the contractor who actually performs the installation and confirms that the work was done according to the compliance plan.
The third is the Certificate of ECC Verification, the CF3R. This one is different — it’s completed by an independent Home Energy Rating System rater, not your contractor. A HERS rater is a certified third-party professional whose job is to field-verify that the installed system actually performs the way the compliance documents say it should. They check things like duct leakage, refrigerant charge, and airflow before a Certificate of Occupancy can be issued.
Homeowners have the right to hire their own independent HERS rater, separate from whoever their contractor works with. Most people don’t know that. What matters is that the HERS step happens — and that your contractor is coordinating it, not leaving it as a loose end for you to figure out after the fact.
A contractor who pulls permits and manages all three compliance documents is a contractor who’s doing the job the right way. One who skips the permit entirely — or who hands you a stack of forms and says “good luck” — is creating a problem you’ll likely discover at the worst possible time, usually when you’re trying to sell the house.
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In California, any HVAC project valued at $1,000 or more in combined labor and materials requires a contractor’s license. The specific classification for HVAC work is the C-20, issued by the California Contractors State License Board. That’s not a general contractor’s license — it’s a specific credential that covers warm-air heating, ventilating, and air-conditioning work.
The C-20 is verifiable. The CSLB maintains a public License Lookup tool where you can search any contractor by name or license number in seconds. Licenses can be active, expired, or suspended — and a contractor who says they’re licensed isn’t always one whose license is currently in good standing. It takes about thirty seconds to check, and it’s worth doing before anyone starts work on your home.
Unlicensed HVAC contracting in California isn’t a gray area. Under Business and Professions Code Section 7028, it’s a criminal misdemeanor. For repeat violations, the penalties include a mandatory 90-day jail sentence and a fine of $5,000 or 20% of the total contract price. Starting July 1, 2026, the minimum civil penalty for unlicensed activity increases to $1,500 per violation.
But the risk to the homeowner is just as real as the risk to the contractor. When an unlicensed contractor does work on your home, they typically skip the permit. No permit means no Title 24 compliance review, no HERS verification, and no documentation that the work was done correctly. If something goes wrong — a system that fails, a fire, a flood — your homeowner’s insurance may not cover it.
There’s also a financial protection angle that most people don’t think about. Under California law, an unlicensed contractor cannot sue you for non-payment. If you’ve already paid them, you can pursue a disgorgement action to recover what you paid, including money spent on materials. That protection sounds useful until you realize it means you’re in a legal dispute instead of a working HVAC system.
The more common scenario is quieter but just as costly: you sell your house years later, the buyer’s inspector finds the unpermitted HVAC work, and you’re either disclosing a liability or renegotiating the sale price. Permitted, compliant work doesn’t just protect you today — it protects the value of your home over time.
Most homeowners get two or three quotes before choosing a contractor. The quotes usually look different — different equipment, different scope, sometimes wildly different prices — and it’s hard to know what’s driving the variation. Some of it is legitimate. Some of it is a contractor leaving out steps they’d rather not deal with.
A few questions cut through the noise quickly. Ask whether the project will be permitted. If the answer is no, or if the contractor suggests skipping the permit to save money or time, that’s a clear signal to walk away. A permit isn’t optional for HVAC replacements in Santa Clara County — it’s how the county verifies the work was done safely and to code.
Ask specifically about Title 24 compliance and who will be coordinating the HERS verification. A contractor who knows what they’re doing will have a clear answer. One who hasn’t thought about it — or who treats it as your problem to figure out — is telling you something important about how the rest of the project will go.
Ask how they determine what size system your home needs. The correct method under California Title 24 is a Manual J load calculation, which accounts for your home’s square footage, insulation, window placement, and local climate conditions. Santa Clara County spans Climate Zone 3 along the western coastal-influenced portions and Climate Zone 4 through most of the inland areas, including the majority of San Jose, Milpitas, and Gilroy — and the right system size varies between them. A contractor who sizes by matching your old unit, or who gives you a number without any calculation, isn’t meeting the code standard.
Finally, ask about their CSLB license number and look it up. It takes thirty seconds and tells you whether the license is active, what classification it covers, and whether there are any disciplinary actions on record. It’s the simplest due-diligence step available, and most people never do it.
Replacing an HVAC system is a significant project. The compliance process that comes with it in California — the permits, the duct testing, the HERS verification, the three compliance documents — isn’t designed to make your life harder. It’s designed to make sure the work is done correctly and that your home is safer and more efficient for it.
The contractor you choose determines how smoothly that process goes. One who pulls permits, explains the compliance steps upfront, and coordinates the HERS rater is doing the job right. One who skips steps or leaves you to figure out the paperwork is creating liability you may not discover for years.
We’ve been navigating this process for Santa Clara County homeowners since 1985. If you have questions about your HVAC replacement, Title 24 compliance, or what the permit process looks like for your specific situation, reach out to us directly. We’ll give you a straight answer — no pressure, no runaround.
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