Title 24 of the California Code of Regulations is the California Building Standards Code. It is published in twelve parts covering administration, building, residential, electrical, mechanical, plumbing, energy, wildland-urban interface, historical buildings, fire, existing buildings, green building standards and referenced standards. People often use Title 24 to mean only the energy calculations, which are Part 6.

Which edition applies to my project?

The 2025 Triennial Edition was published on 1 July 2025 with an effective date of 1 January 2026, so it is the current edition. The previous 2022 edition was published 1 July 2022 and took effect 1 January 2023. Because the code is revised every three years, a project designed near the end of a cycle can be permitted under one edition and built under discussion of the next.

Is Title 24 just the energy report?

No. The energy compliance report your consultant produces addresses Part 6, the California Energy Code. Part 11, CALGreen, is separate and imposes its own requirements. Part 2 or Part 2.5 governs the building itself. Treating Title 24 as a single deliverable is how requirements get missed.

Does that mean the state code is frozen too?

No, and this is worth being precise about because it is widely reported loosely. The restriction described in the bill's digest is on changes made by a city or county to the published standards as they apply to residential units. It is a constraint on local amendment, not a freeze on the statewide code, which continues on its three-year cycle.

Why does local amendment matter to a homeowner?

Because local amendments — sometimes called reach codes — are where unexpected requirements have historically come from. Two adjacent cities on the same state code could impose materially different residential requirements. During the AB 130 window, the scope for that divergence on residential work is narrowed.

Title 24 explained, and what AB 130 froze until 2031

PUBLISHED SEPTEMBER 10, 2026 · UPDATED SEPTEMBER 10, 2026 · REVIEWED BY MILAD KAZEMI

Title 24 of the California Code of Regulations is the California Building Standards Code, and it is not a single document. It is published in twelve parts, including the California Building Code at Part 2, the Residential Code at Part 2.5, the Energy Code at Part 6, the Wildland-Urban Interface Code at Part 7, and CALGreen at Part 11. It is revised on a three-year cycle: the 2025 Triennial Edition was published on 1 July 2025 and took effect on 1 January 2026. Separately, AB 130 bars a city or county from making changes applicable to residential units to those building standards from 1 October 2025 to 1 June 2031, unless a condition such as the Commission deeming them necessary as emergency standards to protect health and safety is met.

Verified as of 10 September 2026 against the California Building Standards Commission and the text published by the California Legislature.

Title 24 is twelve documents

Most homeowners meet Title 24 as a phrase on an invoice — “Title 24 calculations” — and reasonably conclude it is an energy form. It is the entire California Building Standards Code, published in parts:

Part	Code
1	California Administrative Code
2	California Building Code (Volumes 1 and 2)
2.5	California Residential Code
3	California Electrical Code
4	California Mechanical Code
5	California Plumbing Code
6	California Energy Code — the part people mean by “Title 24”
7	California Wildland-Urban Interface Code
8	California Historical Building Code
9	California Fire Code
10	California Existing Building Code
11	CALGreen — California Green Building Standards Code
12	California Referenced Standards Code

The practical consequence is that Part 6 compliance and Part 11 compliance are different obligations with different documentation, and a project can satisfy one while missing the other.

The three-year cycle, and where we are in it

The code is revised triennially. The 2025 Triennial Edition was published on 1 July 2025 and took effect on 1 January 2026. The 2022 edition it replaced was published 1 July 2022, effective 1 January 2023.

This matters for scheduling more than most people expect. A project designed in the last months of a cycle and permitted after the changeover is reviewed against the new edition. The six months between publication and effect exist precisely so that designs can be adjusted, and using them is cheaper than discovering the shift at plan check.

What AB 130 actually froze

AB 130 is usually summarised as a moratorium on new residential building standards. The bill’s own digest is narrower and more useful.

From 1 October 2025 to 1 June 2031 inclusive, it prohibits a city or county from making changes applicable to residential units to the building standards published in the code, unless a specified condition is met — including that the Building Standards Commission deems the changes or modifications necessary as emergency standards to protect health and safety. Over the same period, the Commission is required to reject a modification or change to any such standard affecting a residential unit filed by a city or county, unless a condition is met.

Read carefully, that is a constraint on local amendment. It is not a freeze on the statewide code, which continues on its cycle. Several secondary summaries describe it as applying to state and local standards alike; the digest does not support that reading, and it is worth checking any claim you rely on against the bill itself.

Why it still matters: local amendments were the main source of divergence between neighbouring jurisdictions on residential work. Narrowing them narrows the gap between what your city requires and what the state requires — which makes a project in Calabasas and a project in Woodland Hills more alike than they used to be, at least on building standards.

The connection to stamped drawings

Title 24 is also the reference point for whether your project needs a licensed professional’s stamp at all.

Business and Professions Code § 5537(a) exempts most single-family woodframe design from the Architects Practice Act. Subdivision (b) then provides that if any portion of the structure deviates from substantial compliance with conventional framing requirements for woodframe construction found in the most recent edition of Title 24, or the tables of limitation in the adopted building code, the building official shall require that portion to be prepared by or under the responsible control of a licensed architect or registered engineer, stamped and signed.

So “does this need an engineer?” is, in law, a question about whether the design stays inside Title 24’s conventional-framing provisions. That is covered in do I need a licensed architect for a home addition.

If you are in a fire hazard zone

Part 7, the California Wildland-Urban Interface Code, is a full part of Title 24 in its own right and carries an emergency supplement effective 1 January 2026. Across the Santa Monica Mountains and the Conejo Valley this is not a specialist annex — it drives exterior assemblies, roofing, venting, decking and glazing, and it interacts with defensible space requirements around the building.

Treating it as something the contractor will sort out later is how a design gets rebuilt on paper after plan check.

Sources

Rules change. Confirm anything you are relying on against the agency directly.

Questions we get asked

What is Title 24?: Title 24 of the California Code of Regulations is the California Building Standards Code. It is published in twelve parts covering administration, building, residential, electrical, mechanical, plumbing, energy, wildland-urban interface, historical buildings, fire, existing buildings, green building standards and referenced standards. People often use Title 24 to mean only the energy calculations, which are Part 6.
Which edition applies to my project?: The 2025 Triennial Edition was published on 1 July 2025 with an effective date of 1 January 2026, so it is the current edition. The previous 2022 edition was published 1 July 2022 and took effect 1 January 2023. Because the code is revised every three years, a project designed near the end of a cycle can be permitted under one edition and built under discussion of the next.
Is Title 24 just the energy report?: No. The energy compliance report your consultant produces addresses Part 6, the California Energy Code. Part 11, CALGreen, is separate and imposes its own requirements. Part 2 or Part 2.5 governs the building itself. Treating Title 24 as a single deliverable is how requirements get missed.
What did AB 130 change?: From 1 October 2025 to 1 June 2031 inclusive, AB 130 prohibits a city or county from making changes applicable to residential units to the building standards published in the code, unless a specified condition is met — including that the Building Standards Commission deems the changes necessary as emergency standards to protect health and safety. Over the same period the Commission must reject such a modification filed by a city or county unless a condition is met.
Does that mean the state code is frozen too?: No, and this is worth being precise about because it is widely reported loosely. The restriction described in the bill's digest is on changes made by a city or county to the published standards as they apply to residential units. It is a constraint on local amendment, not a freeze on the statewide code, which continues on its three-year cycle.
Why does local amendment matter to a homeowner?: Because local amendments — sometimes called reach codes — are where unexpected requirements have historically come from. Two adjacent cities on the same state code could impose materially different residential requirements. During the AB 130 window, the scope for that divergence on residential work is narrowed.
How does Title 24 connect to whether I need a stamped drawing?: Directly. Business and Professions Code § 5537(b) provides that where any portion of an otherwise exempt structure deviates from substantial compliance with conventional framing requirements found in the most recent edition of Title 24, or the tables of limitation in the adopted building code, the building official shall require that portion to be prepared by, or under the responsible control of, a licensed architect or registered engineer, and stamped.
Is there a separate code for fire areas?: Yes. Part 7 is the California Wildland-Urban Interface Code, published as its own part of Title 24, and it carries an emergency supplement effective 1 January 2026. If your property is in a fire hazard severity zone, Part 7 is a live part of your project rather than a footnote.

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