What is Title 24?

Title 24 is the California Building Standards Code

Title 24 is the California Building Standards Code — the 24th title within the California Code of Regulations. The CCR has 28 titles; Title 24 is the one reserved for regulations governing the design and construction of buildings, and it applies to all building occupancies throughout the state. Structural, mechanical, electrical, plumbing, fire and life safety, accessibility and green building all sit inside it. The state itself lists the belief that Title 24 covers only energy conservation as a common misunderstanding.

The part I work in is Part 6, the California Energy Code — formally the Building Energy Efficiency Standards, adopted by the California Energy Commission. When someone on a project says they need a Title 24, Part 6 is what they mean, and what they want is a Certificate of Compliance: the document showing the design meets the Energy Code. On single-family work that is the CF1R; on commercial and tenant-improvement work it is the NRCC.

How Title 24 is organized

Title 24 is divided into numbered parts, each named for what is in it. The ones that come up on a permit set:

• Part 2 — California Building Code
• Part 2.5 — California Residential Code
• Part 6 — California Energy Code
• Part 7 — California Wildland-Urban Interface Code, new with the 2025 edition
• Part 11 — California Green Building Standards Code, better known as CALGreen

Part 6 is adopted entirely by the CEC; most other parts carry amendments from several agencies. CALGreen is the part people confuse with the Energy Code, and its energy-efficiency provisions are voluntary. The rest of the list, and who writes each one, is on the parts of Title 24 page.

What “Title 24 compliant” means

“Title 24 compliant” is an industry phrase, not a term the code defines. The code says comply with Part 6. For a newly constructed single-family building that means meeting the mandatory measures, then satisfying either the prescriptive approach or the performance approach. Prescriptive is a checklist. Performance runs an energy model of the proposed design against a standard design, so a weak spot in one place can be paid for by doing better elsewhere. Most of what I build runs the performance path.

What people mean by a “Title 24 report”

Nothing in the code is called a Title 24 report. The document is the Certificate of Compliance, and which one applies depends on the building:

• CF1R — single-family. The code definition runs to several prongs; the ones that come up are an Occupancy Group R-3 building with two or fewer dwelling units, a townhouse, and a Group U building on a residential site. Two dwelling units is what puts a duplex here. The Energy Code carries no definition of an accessory dwelling unit at all, so an ADU is classified by what the work is — detached is a newly constructed building, attached or a garage conversion is an addition, a JADU inside existing conditioned space is an alteration — and every one of those still documents on a CF1R.
• LMCC — low-rise multifamily of three or more dwelling units.
• NRCC — nonresidential: occupancy Groups A, B, E, F, H, I, L, M, S and U, for new buildings, additions and alterations. Hotels and motels run on the nonresidential forms as well.

There is also no such thing as a Title 24 certification. There is a Certificate of Compliance, which is a document, and separately there are certified raters who do field verification. The glossary has the rest of the acronyms.

When Title 24 is required

Part 6 applies to buildings in the covered occupancy groups for which a building permit application, or a renewal, is filed on or after the effective date of the provisions. The permit application is the trigger, not the start of construction — and it fixes the code cycle. The standards are updated every three years: applications filed on or after January 1, 2023 comply with the 2022 Energy Code, and applications filed on or after January 1, 2026 must comply with the 2025 Energy Code. A job permitted on an older cycle stays there, so I still run 2019 and 2022 models.

Within a building, Part 6 regulates the envelope, space-conditioning systems, water heating, pools and spas, solar-ready provisions, indoor and outdoor lighting, electrical power distribution and signs. It reaches existing buildings too: for single-family, Section 150.2 covers additions, alterations and repairs. An addition increases conditioned floor area and volume. An alteration is a change to a building’s water-heating, space-conditioning, lighting or electrical power distribution system, or its envelope, that is not an addition. That is why a bare HVAC change-out pulls in Title 24, why an addition almost always does, and why moving a non-structural interior partition generally does not. Scope by scope, what actually triggers a report is its own page.

Where Title 24 meets the permit

For newly constructed buildings, additions, alterations and repairs regulated by Part 6, the applicant submits the Certificate of Compliance to the enforcement agency, and it has to be approved by stamp or authorized signature before the building permit is issued. When the agency requires plans with the application, the certificates are incorporated into them, which is why the Title 24 sheets belong in the permit set. One narrow exception: for alterations to existing residential buildings needing field verification, where the agency does not require plans, the certificate is approved before final inspection instead.

Written by the state, enforced by your city

Title 24 is a California state regulation, applying to buildings throughout California, but the CEC does not enforce it. The enforcement agency is the city, county or state agency that issues the permit, and cities and counties are required by state law to enforce Title 24. The state code is also a floor rather than always a ceiling: a local government can adopt a stricter reach code, but only after finding it cost-effective and getting a CEC finding that it requires less energy use than Part 6.

Who prepares it

The CEC’s own compliance manual says an energy consultant who understands the code often prepares the CF1Rs. The code splits the roles: a documentation author prepares the compliance document, and a responsible person — someone eligible under Division 3 of the Business and Professions Code to accept responsibility for the building design — reviews and signs it. On every job I take I am the documentation author and you stay the responsible designer.

Compliance documents have to be registered with an approved registry on all newly constructed homes, most additions and many alterations. The CEC ties registration to whether a project needs field verification, and not every project does. I register through CHEERS, included in the rate. The verification itself is done by an ECC-Rater, an independent third party certified by a CEC-approved provider — a HERS rater on 2019 and 2022-cycle permits. Separate trade, and not mine.

Prices

Flat fees, in writing before I start. No hourly, no bid package, no change-order games — the number on the quote is the number on the invoice.

One honest note

Title 24 questions

If yours isn’t here, see the full FAQ or call and ask.