Title 24 HVAC Requirements in California: A 2026 Homeowner Guide

What are Title 24 HVAC requirements in plain English?

Title 24 HVAC requirements are the parts of California's Building Energy Efficiency Standards (Title 24, Part 6 of the state code) that control how heating and cooling equipment is installed and verified. In short, when you replace an air conditioner, furnace, heat pump, or ducts, the state wants proof that the new system is efficient, correctly charged, and not leaking conditioned air into your attic. That proof comes from two things: a mechanical permit and, in most cases, an independent field test.

The California Energy Commission updates these standards on a roughly three-year cycle. Permit applications filed on or after January 1, 2026 fall under the 2025 Energy Code. If your paperwork went in before that date, the older 2022 cycle applies. Either way, the core homeowner obligations are the same: get a permit and pass verification. Whether you are booking central AC installation or a new gas furnace, the code follows the equipment, not the brand.

When does HVAC work trigger a permit and a HERS test?

The trigger is simpler than most homeowners expect: almost any equipment change-out counts. Replacing a condenser, a furnace (FAU), a coil, or a meaningful run of ductwork requires a permit in nearly every California jurisdiction, including like-for-like replacements of the same size and fuel type. Adding or replacing more than about 40 feet of duct, or relocating equipment, also pulls a permit.

On top of the permit, most changeouts require HERS field verification, which the California Energy Commission now administers under the Energy Code Compliance (ECC) program. The rule of thumb: if you touch the refrigerant circuit or the ducts, expect testing. A simple thermostat swap or a capacitor repair usually does not trigger any of this.

• Replace the AC condenser or coil: permit plus refrigerant charge and airflow verification.
• Replace the furnace or air handler: permit plus, in most cases, duct leakage testing.
• Replace or add significant ductwork: permit plus duct leakage testing.
• Full system changeout: permit plus all three HERS/ECC checks.

What does HERS (ECC) verification actually check?

A HERS rater, now called an ECC field verifier, is a state-certified third party who acts as a special inspector. The single most important rule: they must be independent. Your HVAC contractor cannot test and sign off on their own work, which is exactly what makes the result trustworthy for the city and for a future buyer. There are three main checks, and not every job needs all three.

• Duct leakage: the rater seals every register and pressurizes the duct system to measure total leakage. A brand-new duct system must test at or below 5 percent; altered or existing ducts must reach 15 percent or better.
• Refrigerant charge: for AC and heat pump work, the rater measures subcooling (TXV systems) or superheat (fixed-orifice systems) to confirm the charge matches the manufacturer's spec within a tight tolerance.
• Airflow and fan power: the rater confirms the system moves enough air across the coil, generally around 350 CFM per ton on new equipment and near 300 CFM per ton on retrofits, and that the blower is not wasting energy.

An overcharged or undercharged system can still blow cold air while quietly wasting energy and shortening equipment life, which is precisely why the state built independent verification into the code.

Why do Title 24 HVAC requirements matter for your home?

It is easy to see the permit and testing as red tape, but each requirement maps to a real benefit. Safety comes first: a permitted job means an inspector confirms gas connections, electrical, and combustion venting are correct on furnace work, protecting your family from carbon monoxide and fire risk. Efficiency is next. A correctly charged, properly airflowed, low-leakage system delivers the SEER2 rating you paid for instead of quietly bleeding 20 to 30 percent of your conditioned air into the attic.

Resale and insurance are the ones homeowners forget. Unpermitted HVAC work can surface during escrow, force a costly retroactive permit, or even let an insurer deny a claim. A finalized permit and a HERS/ECC certificate are clean paperwork that a buyer's agent and inspector can verify. If you are weighing the full picture, our guide to AC replacement cost in California breaks down where permit and testing fees fit into a realistic budget.

How much do the permit and HERS test add to the job?

The permit fee itself is set by your city or county and is usually modest, often issued over the counter or online the same day for a straightforward mechanical changeout. The HERS/ECC verification is a separate third-party cost, commonly in the range of a few hundred dollars depending on how many tests your job needs and your region.

A reputable installer folds both into an upfront quote so there are no surprises. At Alex Air & Heating we handle the permit filing, coordinate the independent rater, and schedule the city inspection as part of the install, and we quote it all before work begins. Be cautious of any bid that is suspiciously low and silent on permits, that is usually a sign the work will not be verified or documented.

How does a licensed installer handle Title 24 for you?

The value of a licensed, EPA-608-certified contractor is that Title 24 compliance becomes invisible to you. We pull the mechanical permit with your local building department, size the equipment properly, install to code, register the job in the state compliance database, bring in the independent HERS/ECC rater, and walk the final inspection. You get a working system and a complete paper trail.

This is also where local knowledge pays off. Whether you need furnace replacement or a full duct replacement, the process is smoother when your contractor already knows the counter staff and inspectors in your city. A statewide code applied by a crew that has never pulled a permit in your town is where delays happen.

Do these rules apply in Ontario and the Inland Empire?

Yes. Title 24 is a statewide code, so the same requirements apply from the coast to the Inland Empire. What changes locally is the counter: permits are pulled with each city's own building department. We regularly handle permits and HERS/ECC verification for homeowners in Ontario, Rancho Cucamonga, Chino, Upland, and Pomona, and each of those cities requires the permit be filed with its local building division before work is finalized.

Because we are based in Ontario, CA, we know how each Inland Empire jurisdiction routes mechanical permits and schedules inspections. If you are starting a project, our Ontario AC installation page shows how the permit, testing, and inspection steps fit together for a local, code-compliant job.