The 2025 Title 24 changeover: which edition governs your California permit
California runs a three-year code cycle across thirteen parts of Title 24. The 2025 edition is now the governing cycle, and the 2022 edition still applies to applications complete on or before December 31, 2025, which means projects in flight right now span both.
California does not adopt a single building code. It adopts Title 24 of the California Code of Regulations (the California Building Standards Code), which is thirteen separate parts, each on its own relationship to a national model code, all published on a three-year cycle by the California Building Standards Commission.
The 2025 edition is the current cycle. The 2022 edition remains the governing code for projects whose applications were complete on or before December 31, 2025. Both are live in the review queue right now.
What the 2025 cycle adopts, part by part
| Part | Code | Based on |
|---|---|---|
| Part 1 | California Administrative Code (CAC) | State administrative provisions |
| Part 2 | California Building Code (CBC) | 2024 International Building Code |
| Part 2.5 | California Residential Code (CRC) | 2024 International Residential Code |
| Part 3 | California Electrical Code (CEC) | 2023 National Electrical Code |
| Part 4 | California Mechanical Code (CMC) | 2024 Uniform Mechanical Code |
| Part 5 | California Plumbing Code (CPC) | 2024 Uniform Plumbing Code |
| Part 6 | California Energy Code | State-authored (no national base) |
| Part 7 | California WUI Code (CA-WUIC) | 2024 International WUI Code |
| Part 8 | California Historical Building Code (CHBC) | State-authored |
| Part 9 | California Fire Code (CFC) | 2024 International Fire Code |
| Part 10 | California Existing Building Code (CEBC) | 2024 International Existing Building Code |
| Part 11 | CALGreen | State-authored |
| Part 12 | California Referenced Standards Code | Referenced standards |
Two of these carry the most weight in review and are the most commonly under-read. Accessibility lives in CBC Chapter 11B (Part 2) and is a California standard, not the federal ADA. It is stricter in places, and a set drawn to the ADA will not automatically pass a California accessibility review. The Energy Code (Part 6) is authored in California with no national base document, so intuitions carried from IECC practice do not transfer.
How to tell which edition governs a specific project
The governing edition attaches to the permit application, not the drawing set. In practice the anchor is the date the application was deemed complete by the department, not the date of your title block, not the date you uploaded, and not the date a plan checker picked it up.
If your project's application-complete date is on or before December 31, 2025, the 2022 Title 24 governs. After that date, the 2025 edition does. If the date is close to the line, get the department's determination in writing before you resubmit. A resubmittal can reset assumptions you were relying on.
The trap is a project that started under one edition, took a correction cycle, and resubmits after the changeover. Whether it stays under the original edition depends on how the department treats completeness on resubmittal, and departments do not all treat it the same way.
The state edition still is not the whole answer
Title 24 is what California adopts. What a specific city enforces is Title 24 plus that city's amendments, adopted by local ordinance and filed with the state. California cities can adopt standards stricter than the state code where they make an express local finding (Health & Safety Code 17958.5), and many do, particularly on fire access, sprinklers, and grading.
That means "2025 CBC" is the correct answer to the state question and an incomplete answer to the review question. We cover the difference in why local amendments drive plan-check corrections, and the adopted editions plus local amendments for California and its cities are in the code library.
Catch the corrections before the city does
Architechtura runs an automated building-code compliance review over your plan set, resolving the jurisdiction, the adopted edition, and the local amendments, then returning cited findings by discipline.
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