Permits and rebates · independent publisher, not a contractor
What is Title 24 HVAC compliance?
Title 24 Part 6 is California's building energy code. For a homeowner replacing an AC or heat pump, it means the job needs a permit, the ducts are sealed and tested, and an independent rater verifies the work before the permit can close.
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- Title 24 in one minute
- What triggers Title 24 on an AC job
- Which jobs carry which checks
- The tests, in plain terms
- Who checks the work
- Why your climate zone matters
- What Title 24 means for your quote
- Terms you will see on the permit and quote
- A worked example: replacing a Valley AC
- Five common Title 24 mistakes on LA jobs
- What happens if the permit is skipped
Title 24 in one minute
What the rater checks, form by form: HERS (ECC) testing on an LA AC replacement.
Title 24 of the California Code of Regulations holds the state's building standards. Part 6 is the energy code, revised by the California Energy Commission on a three-year cycle.
Permit applications filed on or after 1 January 2026 fall under the 2025 edition (CEC). Your installer works to the edition in force on the day the permit was applied for, not the day the work happens.
What triggers Title 24 on an AC job
The California Energy Commission says replacing or altering an HVAC unit needs a permit, the contractor seals and tests the ducts, and a third-party rater verifies the work, including duct leakage.
Under Title 24 Part 6, replacing the condensing unit, air handler or coil is an alteration that triggers duct sealing. Adding more than 25 feet of new duct means the whole system must test at 10 percent leakage or less. Refrigerant charge checks apply to heat pumps everywhere and to ACs in zones 2 and 8–15.
Verify
The detail above follows the 2022 code text as published by Energy Code Ace. The 2025 edition applies to 2026 permits; confirm the current wording with your building office or the CEC before you rely on a specific threshold.
In practice almost every LA change-out triggers it. Swapping the condenser and coil, replacing a furnace and coil together, or converting to a heat pump are all alterations under Part 6.
Which jobs carry which checks
| The job | Permit | Duct sealing and test | Refrigerant check |
|---|---|---|---|
| Replace outdoor unit and coil, reuse ducts | Yes | Yes, on the existing ducts | Depends on climate zone for AC; heat pumps in every zone |
| Replace furnace and AC together | Yes | Yes | As above |
| AC plus furnace to a ducted heat pump | Yes, often with an electrical permit too | Yes | Yes, heat pumps in every zone |
| Add more than 25 ft of new duct | Yes | Whole system must test at 10% leakage or less | As above |
| New ductless mini-split | Yes | No ducts to test | Follow the manufacturer and code; ask the installer |
Built from Energy Code Ace (CEC-supported), Single-Family Compliance Manual ch. 9, § 150.2(b)1E–F, 2022 code text; confirm against the 2025 code in force since 1 January 2026 (verify against the 2025 code) and California Energy Commission, "Building Energy Efficiency Resources for Single Family Homes". The mini-split row is our reading: there are no ducts to seal, but the permit still applies.
The tests, in plain terms
- Duct leakage test. The ducts are sealed off and pressurised with a calibrated fan. The leakage it measures is compared with the limit the code sets for that job. Leaky attic ducts are common in older LA houses.
- Refrigerant charge verification. A check that the system holds the right amount of refrigerant. Too much or too little cuts capacity and efficiency.
- Airflow and fan checks. Some jobs also verify airflow across the coil. Ask the installer which checks your job needs.
Why it matters to you
ENERGY STAR says improper installation can reduce system efficiency by up to 30 percent. The Title 24 tests are the state's way of catching the most common of those mistakes before the permit closes.
Who checks the work
From 1 January 2026 the CEC's Energy Code Compliance (ECC) program took over field verification from the HERS program, so the third-party rater on a 2026 change-out works under ECC.
The contractor does the sealing and runs its own tests. The rater then verifies them independently and registers the result. The building inspector relies on that registration before signing off.
- Permit applied for by the contractor, in their name.
- Installation, including duct sealing.
- Contractor tests and records the results.
- Rater verifies and registers them under ECC.
- Final inspection closes the permit.
Why your climate zone matters
Los Angeles County spans building climate zones 6, 8, 9, 14 and 16. The coast (Santa Monica, Long Beach) is zone 6 and the San Fernando Valley zone 9, so the same change-out can carry different tests a few miles apart. Look up an address with the CEC climate zone tool.
Some checks depend on the zone. Two similar change-outs a few miles apart, one in Santa Monica and one in the Valley, can carry different tests. Ask the contractor which zone they used on the permit.
Climate zone detail: California Energy Commission building climate zones (CA State Geoportal); zone assignment by address (verify by address).
What Title 24 means for your quote
Title 24 adds lines to an honest quote. Published Los Angeles add-on costs, from the sources on our cost guide:
- The quote should include the permit and say who books and pays the rater.
- It should say what happens, and at what price, if the ducts fail the leakage test.
- A quote that leaves out the permit also leaves out the tests. LADWP's heat pump rebate requires the final approved permit.
Terms you will see on the permit and quote
| Term | What it means for you |
|---|---|
| Part 6 | The energy section of Title 24, the part that sets the HVAC tests |
| Alteration | Changing or replacing part of an existing system; a change-out counts |
| Duct leakage test | A calibrated fan pressurises the ducts and measures how much air escapes |
| Refrigerant charge verification | A check that the system holds the right refrigerant charge |
| ECC rater | The independent verifier under the CEC's Energy Code Compliance program, which replaced HERS for code checks in 2026 |
| Registered result | The rater's verification filed so the building inspector can rely on it |
| Climate zone | The CEC zone for your address; some checks depend on it |
| Finalled permit | A permit the inspector has signed off; the job is closed |
Ask the installer to explain any of these on your permit you do not recognise. A contractor who does change-outs regularly will know them.
A worked example: replacing a Valley AC
A Woodland Hills house has a 20-year-old central AC with a gas furnace and attic ducts. The owner replaces the condenser and coil and keeps the furnace.
- Permit: the contractor applies to LADBS, because Woodland Hills is in the City of Los Angeles.
- Ducts: the change-out is an alteration, so the existing ducts are sealed and leak-tested.
- Refrigerant: the Valley is climate zone 9, one of the zones where an AC charge check applies under the 2022 text (verify for 2025).
- Rater: an ECC rater verifies and registers the results.
- Final: the inspector signs off and the permit closes.
If the ducts fail
Old attic ducts often leak. The quote should already say what extra sealing costs. Published LA duct repair runs $800–$4,500; new ductwork $3,500–$8,000.
Five common Title 24 mistakes on LA jobs
- No permit at all, so no tests and no LADWP rebate.
- A quote silent on the rater, leaving a surprise bill or a delay.
- No price for failed ducts, so the duct work becomes a change order at any price.
- The wrong office. A Burbank or Glendale house needs that city's permit, not LADBS.
- Final payment before the final. Once paid, an unclosed permit is harder to chase.
What happens if the permit is skipped
The real cost of "no permit"
- No Title 24 tests, so nobody independent checks the ducts or the charge.
- No LADWP heat pump rebate, which needs the final approved permit.
- An open or missing permit can come up when the house is sold.
- Since 1 January 2025, work totaling $1,000 or more in labor and materials needs a CSLB license. Below that, an unlicensed person may do the job only if no building permit is needed and they hire no workers. An AC installation needs a permit, so it needs a license at any price.
Work out which office issues yours on the Los Angeles AC permit guide.
Sources
- California Energy Commission, "Building Energy Efficiency Resources for Single Family Homes" (retrieved 2026-09-29)
- Energy Code Ace (CEC-supported), Single-Family Compliance Manual ch. 9, § 150.2(b)1E–F, 2022 code text; confirm against the 2025 code in force since 1 January 2026 (retrieved 2026-09-29) — verify before relying on it
- California Energy Commission, "Home Energy Rating System (HERS) Program" (retrieved 2026-09-29)
- California Energy Commission building climate zones (CA State Geoportal); zone assignment by address (retrieved 2026-09-29) — verify before relying on it
- CSLB press release #24-21, "Handyperson Exemption to Increase to $1,000 in 2025" (AB 2622) (retrieved 2026-09-29)
- 10 CFR 430.32(c), Electronic Code of Federal Regulations (retrieved 2026-09-29)
- California Energy Commission, 2025 Building Energy Efficiency Standards (retrieved 2026-10-18)
- ENERGY STAR, "Heat & Cool Efficiently" (retrieved 2026-10-18)
- Reliable Heating and Air (Woodland Hills), AC installation cost in LA and Ventura County (retrieved 2026-09-29)
- Cold Cloud (Glendale), central air cost in Los Angeles (retrieved 2026-09-29)
- E & A Mechanical (Tujunga), heat pump installation cost in Los Angeles (retrieved 2026-09-29)
- HVACProjectCost.com, Los Angeles HVAC replacement cost (retrieved 2026-09-29)
Questions
Does Title 24 apply to a straight AC swap?
Yes. Replacing the outdoor unit, coil or air handler is an alteration under Part 6, which brings duct sealing and testing and third-party verification.
Which Title 24 edition applies to my job?
The edition in force when the permit was applied for. Applications filed on or after 1 January 2026 use the 2025 Energy Code, per the California Energy Commission.
What is the difference between HERS and ECC?
From 1 January 2026 the CEC's Energy Code Compliance (ECC) program took over field verification from the HERS program, so the third-party rater on a 2026 change-out works under ECC.
Who pays if my ducts fail the leakage test?
Whoever the contract says. Put it in writing before work starts, with a price or a rate for any extra duct sealing.
Does a ductless mini-split need Title 24 tests?
It still needs a permit. There are no ducts to leak-test, but other checks can apply. Ask the installer which verification the permit lists.
How long does the rater visit take?
It depends on the house and the tests. Ask the contractor when the rater is booked and whether you need to be home.
Can I hire my own rater?
Contractors usually arrange the rater. If you want to choose one, agree it before work starts so the permit paperwork matches.
Does Title 24 require a high-efficiency unit?
Federal law sets the minimum efficiency for new equipment. In California, a new split AC needs 14.3 SEER2 below 45,000 Btu/h plus an EER2 minimum.
Does Title 24 apply in every LA-area city?
Yes. Title 24 is state law, so it applies everywhere in California. What differs city to city is the office that issues the permit and, by climate zone, some of the checks.
Does replacing only the thermostat need a permit?
Rules vary by office and by what changes. Ask your building office; a thermostat alone is usually not the alteration that triggers duct testing.
Next step
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- Tell us about the job. Service, ZIP, property and timing. The form says right away if your ZIP is outside the area.
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- Compare what comes back. Line the written quote up against the published ranges and the quote checklist.
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