Do You Need a Permit to Replace an HVAC System or Water Heater in California?

Your building department decides whether a permit is needed; the Energy Code does not. What the code settles is that swapping an air conditioner, furnace or water heater is an alteration, not a repair, so Part 6 applies with or without a permit. Where a permit is issued, Section 10-103(d)1 bars the department from issuing it unless the work is designed to comply.

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Two questions, two authorities

Whether a permit is needed is the department’s call under its own rules. What the equipment must meet is Part 6’s call. The compliance manual treats a repair as the renewal of a part for maintenance and replacing any equipment the Energy Code regulates as an alteration, so a like-for-like changeout is regulated even though nothing about the house changes. The department’s answer on the permit does not alter what the new equipment must do.

Water heater: a light paper trail

Replacing a water heater needs no field verification. For alterations like that, Section 10-103(a)1C lets a department require no Certificate of Compliance or a simplified one, and adds that the allowance does not authorize work that breaks the code. The new unit still has to be one of the replacement types in Section 150.2(b)1H, set out on water heater requirements.

HVAC: the verification drives the paperwork

A changeout brings duct testing and, for most systems, a charge and airflow check by an ECC-Rater, the role called a HERS rater until 1 January 2026. Because field verification is required, the certificate is registered with an ECC-Provider. Where the department does not require plans with the application, Section 10-103(a)2A lets that certificate be approved before final inspection rather than before the permit, and the compliance manual says the HVAC-changeout certificate, CF1R-ALT-02-E, can be submitted at final. Departments differ, so ask what yours wants at the counter. The triggers are on HVAC replacement and coil and compressor swaps.

At final inspection

For a house, final inspection is not complete until compliance is verified (Section 10-103(d)2), so a missing verification certificate holds it up. That certificate must state the building permit number the work was done under (Section 10-103(a)5A), and the department requires the builder to leave the owner copies of the installation and verification certificates (Section 10-103(b)1A).

Which code edition

The 2025 Energy Code applies to permit applications submitted on or after 1 January 2026, and the building department sets the application date. A swap permitted under an earlier application follows the earlier code; see expired permits for what a lapsed permit does to that date.

If the work is already done

The code requirements did not lapse because no permit was pulled. See unpermitted work, and who enforces Title 24 for the department’s role.

Common Title 24 Questions

  1. When is Title 24 required for a home?
  2. Does a remodel need Title 24?
  3. Does a room addition need Title 24?
  4. What plans are needed for a residential Title 24 report?
  5. How much does a residential Title 24 report cost?
  6. How long does a residential Title 24 report take?

Frequently Asked Questions

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