Who Enforces Title 24?
Your local building department — at plan check and again at inspection. The Energy Commission writes the standards but does not enforce them project by project, and some measures are verified by independent third-party technicians instead.
The Energy Commission writes; the city enforces
The California Energy Commission develops the standards, updates them on a three-year cycle, approves the compliance software and publishes the forms. What it does not do is check your project.
Enforcement sits with the local authority having jurisdiction — the city or county building department. That is why the code is uniform statewide while the experience of complying with it varies noticeably between jurisdictions.
Two enforcement moments, testing different things
Plan check reviews the documents before a permit is issued. It asks whether the design, as documented, complies — a paper test, and the one most people mean by compliance.
Inspection checks the building. It asks whether what was built matches what was approved. A project can pass plan check comfortably and fail here, which is the entire reason the certificate families separate compliance from installation.
The third parties who verify what nobody can see
Some measures cannot be confirmed by looking. Duct leakage, refrigerant charge, airflow and the behaviour of a lighting control are all invisible to visual inspection, so the code delegates them to independent verification.
On residential and multifamily work that means an ECC-Rater — the role called a HERS rater until 1 January 2026 — registering results through an ECC provider's data registry. On nonresidential work it means acceptance testing, documented on NRCA forms — by a technician certified through an approved provider for lighting controls and mechanical systems, and by a field technician for covered process equipment.
These people are not employed by the building department, and that is the point: the results are independent of both the contractor who did the work and the authority approving it.
What happens when a project does not comply
In practice, it does not progress. A non-compliant submittal draws plan check comments and the permit waits. A non-compliant installation fails inspection and the work is corrected before sign-off. A missing acceptance test holds final sign-off.
The mechanism is procedural rather than punitive, and it is effective precisely because it sits on the critical path. The cost of non-compliance is usually measured in programme delay and rework rather than in penalties.
Why local variation is worth planning for
Departments differ in how they want documents submitted, how thoroughly energy documentation is reviewed, and how quickly comments come back. Some jurisdictions also adopt reach codes — local ordinances exceeding the state standards — which means the applicable requirements can be stricter than the state code in that city.
Confirming local submittal expectations early is a small piece of work that prevents a resubmittal, which is the most avoidable delay in the whole process.