Which Title 24 edition applies? Your permit application date decides

The question every design office is asking right now

The 2025 edition of Title 24 became enforceable on January 1, 2026. If your project started under the 2022 code, you already know the question: which edition governs my plans?

Here's the thing: most people guess wrong. They assume it's the code in effect when the permit issues, or when they break ground, or when the building gets its final. It's none of those. California answers this with one clean rule — and it turns on a single date.

The rule: the day you applied

Under Health and Safety Code §18938.5, the building standards in effect on the date your permit application is submitted are the standards applied to your plans and to the construction performed under that permit.

Verified against the text of Health and Safety Code §18938.5(a): "Only those building standards approved by the commission, and that are effective at the local level at the time an application for a building permit is submitted, shall apply to the plans and specifications for, and to the construction performed under, that building permit."

Not the issue date. Not groundbreaking. Not final inspection. The submittal date. The Building Standards Commission says it plainly in its own FAQ: the date of plan submittal will dictate which edition of Title 24 to use.

What that means for 2025 vs. 2022

The 2025 edition of Title 24 was published July 1, 2025 and took effect January 1, 2026. Line that up with the submittal rule and the handoff is clean:

• A complete permit application filed on or before December 31, 2025 is reviewed under the 2022 codes.
• A complete application filed on or after January 1, 2026 gets the 2025 codes — including the January 2026 errata.

So a project that's been in design for a year doesn't get bumped to the new edition just because the calendar rolled over to 2026. If the application landed in 2025, it stays on the 2022 books. That's not a courtesy from your plan checker — it's what the statute requires.

The same math governs the brand-new California Wildland-Urban Interface Code (Part 7), which debuts in the 2025 edition: it reaches applications submitted on or after January 1, 2026, while earlier applications are reviewed under the prior cycle's WUI provisions.

"Submitted" means the application — but confirm what counts

The trigger is the application, not the approval. That's the whole point of the rule: it shields a design from a code change that lands mid-review.

What the statute doesn't do is define, statewide, the exact moment an application becomes "complete." That's handled at the counter. Jurisdictions vary on what a complete submittal requires before the clock is treated as started — so if your filing date is close to a cycle boundary, verify with your local jurisdiction what they count as the submittal date, and get it in writing.

Where the edition can still flip

The lock isn't permanent. Section 18938.5 itself carves out situations where a later application — under a newer edition — is what applies:

• An expired permit. If a permit is deemed expired because the work wasn't commenced within 12 months of the permit or was abandoned, the new application is subject to the codes in effect on the date of that new application.
• A permit revoked for error. If the building official suspends or revokes a permit that was issued in error, the same reset applies.

The practical takeaway: a stalled or lapsed project can lose its grandfathered edition and land on the current code when it comes back to life. If you're phasing work or sitting on an approval, that 12-month window is worth watching — and worth confirming with your jurisdiction before it closes.

The rule outlasts this cycle

None of this is special to the 2025 rollout. Section 18938.5 is the permanent mechanism California uses every three years. When the next triennial edition publishes and takes effect, the same question will have the same answer: look at the date the application was submitted. Learn the rule once and you never have to relitigate it.

What CrossBeam does with it

CrossBeam pins every requirement it checks to a specific Title 24 edition, so a plan filed under the 2025 edition is measured against the 2025 code and its errata, while a project filed in 2025 stays on the 2022 books. That means the answer to "which code applies here" is built into the review instead of left to memory at the counter.