Title 24 Compliance in California
Title 24 compliance runs in eight steps: the design is documented on a certificate of compliance that the building department approves before it issues a permit. During construction, installers sign certificates of installation, an ECC-Rater or acceptance test technician tests what cannot be seen, and the inspector checks it all before final sign-off.
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Title 24 compliance is a sequence with several people in it, not a single document. The Energy Commission does not enforce the code directly. The local building department does, and the builder and owner carry the primary responsibility for showing compliance. What the code requires is covered in Title 24 requirements in California, and what the design-stage report contains is in Title 24 report.
The eight steps, and who does each
- Classify the project: the designer or energy consultant
- Choose the compliance path: the documentation author, with the designer
- Prepare the certificate of compliance: the documentation author, signed by the responsible person
- Register it where required: the person responsible for the certificate, through an ECC provider data registry
- Plan check and corrections: the building department, with the applicant
- Certificates of installation: the installing contractors
- Field verification or acceptance testing: an ECC-Rater, or an acceptance test technician
- Final inspection: the building department
1. Classify the project
Two questions come first: what kind of work, and what kind of building. The work is new construction if the building has never been used or occupied, an addition if it increases conditioned floor area and volume (turning a garage into living space counts), or an alteration if it changes the envelope, heating and cooling, water heating, lighting or electrical distribution without adding area. Replacing regulated equipment is an alteration, not a repair.
The building is single-family (Group R-3, including duplexes, townhouses and ADUs), multifamily (Group R-2 and R-4, other than hotels) or nonresidential, which includes hotels and motels. The classification fixes the code sections and the forms. A new detached ADU is new construction; the same unit built over an existing garage is an addition.
Where it gets stuck: an alteration so extensive that the department treats it as new construction, or a townhouse or mixed-use building that the designer classifies one way and the department another. The department's classification is the one that counts, so confirm it early.
2. Choose the compliance path
Every project meets the mandatory measures, then either the prescriptive approach, where each component meets the package for the climate zone, or the performance approach, an energy model in Energy Commission-approved software measured against a standard design. Additions and alterations generally use the prescriptive approach, with performance as an option. On nonresidential projects, prescriptive certificates come from the Energy Code Ace Virtual Compliance Assistance tool, and performance needs an approved compliance model, which produces the NRCC-PRF-01.
Where it gets stuck: a design sent down the prescriptive route that misses one item, such as glazing area or an equipment efficiency. The performance approach may still show compliance without changing the design. See prescriptive vs performance and why a design does not comply.
3. Prepare the compliance documentation
The certificate of compliance is the CF1R for single-family work, the LMCC for multifamily buildings of up to three habitable storeys, and the NRCC set for nonresidential buildings and taller multifamily. It identifies every energy feature the design relies on and uses the same project name and location as the plans. A CF1R also carries the heating and cooling load results.
Two signatures are required. The documentation author prepares it and certifies that it is accurate and complete; the code sets no qualification for that role. The responsible person, someone eligible under Division 3 of the Business and Professions Code to take responsibility for the design, signs to certify that it complies. On a commercial job, a technician may prepare the mechanical NRCC but the engineer of record signs it. Where plans are submitted, the certificate has to be incorporated into them. See who can prepare a Title 24 report.
Some projects need less. For residential alterations with no field verification, such as a water heater or window replacement, and additions under 300 square feet with none, the department may waive the certificate or accept a simplified one. New nonresidential buildings need more: commissioning documents, including a design review signed by a licensed engineer or architect, or a licensed contractor under their supervision.
Where it gets stuck: a certificate that does not match the drawings. If the window schedule, equipment schedule or insulation details disagree with it, plan check will find it.
4. Register it where required
For low-rise residential buildings, meaning single-family homes and multifamily buildings of up to three habitable storeys, a project whose compliance depends on field verification must register its certificates with an ECC provider data registry. On single-family work that means all newly constructed homes, most additions and many alterations. The registry numbers each document and keeps the signed record, the copy on the plans must be the registered one, and the later certificates go through the same registry.
CHEERS is approved by the Energy Commission as an ECC-Provider for the 2025 Energy Code. CalCERTS, once the other familiar name, ceased operations on 2 August 2024. Registration is explained in are your reports CHEERS registered.
Where it gets stuck: multifamily. As of the Energy Commission's Winter 2026 newsletter, no ECC provider registry had been approved for prescriptive LMCC forms on new construction, and building departments were encouraged to collect the documentation in the meantime. Ask your department what it accepts before submitting.
5. Plan check and corrections
The plans examiner compares the certificate with the rest of the submittal: window U-factor and SHGC against the window schedule, HVAC efficiencies against the equipment schedule, insulation against the framing details. The department can ask for supporting material, including the compliance software input file. Vague, missing or inconsistent information comes back as a correction, and the applicant revises and resubmits.
The permit is issued only once the department has determined in writing, usually with its approval stamp, that the design complies with the Part 6 edition in effect on the date the permit was applied for. One exception: for a residential alteration that needs field verification but no plans, such as an HVAC changeout, the registered certificate can be approved before final inspection instead.
Where it gets stuck: the certificate and drawings disagree, or a late design change never made it into the certificate. See residential plan check corrections.
6. Construction and certificates of installation
As each regulated feature goes in, the person responsible for installing it completes a certificate of installation: the CF2R on single-family work, the LMCI on low-rise multifamily and the NRCI on nonresidential. That person must be eligible under Division 3 of the Business and Professions Code to take responsibility for the work, though signing can be delegated in writing to an authorised representative. The certificate states the permit number and confirms the installation matches the approved plans. Where field verification is required, the builder or installer also performs the initial test and registers the CF2R.
The building department inspects in stages; on a new home, typically before the slab is poured, at rough framing, at insulation, at drywall and at final. Where work will be covered up, the department can require its certificate first.
Where it gets stuck: substitutions. A different window or heat pump, or a change to which lights are on daylighting controls, can take the building out of compliance; it then needs amended plans and certificates approved by the department. See CF2R and NRCI.
7. Field verification and acceptance testing
Some measures cannot be confirmed by looking. On residential projects an ECC-Rater, certified by an Energy Commission-approved ECC-Provider, tests them in the field; the role was called a HERS rater until 1 January 2026. A new home with central HVAC, for example, needs its duct leakage, airflow, fan watt draw and exhaust fans verified. The rater must be independent: no financial interest in the builder, designer or subcontractor who signs as responsible person, and no construction work on the site. The rater checks the CF2R against the CF1R, will not sign a CF3R without a registered CF2R from the installer, and records a pass or a fail. A fail is corrected and retested before a passing CF3R is issued. See what is an ECC-Rater and CF3R.
Nonresidential projects use acceptance testing. Lighting controls and mechanical systems are tested by an acceptance test technician certified through a provider approved by the Energy Commission, and the results go on the NRCA, which carries that provider's watermark. Unlike an ECC-Rater, the technician does not have to be independent and is often the installer. In some instances an NRCV, completed by an ECC-Rater, is also required. See acceptance testing.
Where it gets stuck: access. Duct tests need reachable ducts, insulation checks need open cavities, and controls tests need running systems. The measures that need verification are listed on the certificate of compliance, so they can be booked from the start.
8. Final inspection
At final, the inspector confirms that what was installed matches the approved plans and the certificate of compliance. Every required certificate of installation, acceptance and verification must be posted or available, signed and, where required, registered. The department may not issue the final certificate of occupancy until that is confirmed, and for a Group R-3 home the final inspection is not complete until it is. The builder then leaves copies of the compliance documents in the building for the owner, with operating, maintenance and ventilation information. See what happens after you receive your report.
How Title24.Pro handles steps 2 to 5
We take on the design-stage part. From your plans we choose the compliance path and prepare the certificate of compliance your project needs: the CF1R, the LMCC or the NRCC set. Where the project requires it, we register the documentation with CHEERS. When plan check returns comments on the energy documentation, we revise it, and revisions are unlimited until the project complies.
- ADU: from $199 for up to 1,000 sq ft, then $9 per additional 100 sq ft
- Residential: from $245 for up to 3,500 sq ft, then $49 per additional 500 sq ft
- Multi-Family: from $345 for up to 4 units and 4,000 sq ft, then $95 per additional unit and $25 per additional 500 sq ft
- Commercial: quoted per project
Standard turnaround for ADU, residential and multi-family reports is 2–3 business days, with a 24-hour rush for $95. The report arrives as a permit-ready PDF by email, and the whole process is 100% online. Steps 6 to 8 belong to your builder, installers, ECC-Rater or acceptance test technician and building department.
Frequently Asked Questions
The builder and the building owner carry the primary responsibility for showing compliance. The responsible person certifies the design on the certificate of compliance, each installer certifies their own work, and the building department decides whether the project passes.
On residential projects, no. Field verification is done by an ECC-Rater, who must be independent of the builder, the designer and the installing subcontractor. On nonresidential projects, acceptance tests for lighting controls and mechanical systems are done by a certified acceptance test technician, who may be the installer.
If the change could take the building out of compliance, it has to be brought back into compliance on amended plans and an amended certificate of compliance, approved by the building department. Window and equipment substitutions are typical examples.
The failure is recorded in the registry, and any copy printed from it is watermarked as a fail. The builder or installer corrects the work, the rater retests, and only then is a passing CF3R issued.
No. Registration applies to low-rise residential projects whose compliance depends on field verification, so many simple alterations, such as a water heater or window replacement with no field verification, do not need it; see CHEERS registration.