California Title 24 Energy Compliance: 2025 Energy Code, CF1R Forms and ECC (HERS) Testing

A California rule, not a national one

If you are building outside California, this page is mostly background. Other states write their own energy codes, and the U.S. Department of Energy measures state residential codes against the International Energy Conservation Code (IECC), with ASHRAE Standard 90.1 as the benchmark for commercial buildings. Your local building department will tell you which IECC edition or state version applies. The forms, raters and data registries described below are specific to California.

Inside California, Title 24 of the California Code of Regulations has several parts. Part 6 is the Energy Code, and Part 11 is CALGreen, the green building code. When a plan checker or contractor says "Title 24 report," they almost always mean the Part 6 energy compliance documents.

The 2025 Energy Code: dates that matter

The trigger is the date the permit application is filed, not the date construction starts. The CEC also says the change is not retroactive. A project permitted under the 2022 code stays under the 2022 code, and its testing follows 2022 rules.

One practical result: a report modeled with 2022 software won't work for an application filed in 2026. Title 24 Calcs, a California report provider, warns that reports prepared with 2022-code software are not valid for permits submitted after January 1, 2026. If your plans sat on a shelf for a year, ask your energy consultant to rerun them.

Which projects need Title 24 compliance

Title 24 Part 6 covers most residential and nonresidential buildings in California. Projects fall into three groups.

New construction

New single-family homes, detached ADUs and multifamily buildings need a full compliance package. For new homes, the CEC says the 2025 code expands the use of heat pumps, encourages electric readiness and strengthens ventilation standards.

Additions

Additions that add conditioned floor area need energy compliance. The CEC's single-family forms split additions by size: CF1R-ADD-01-E covers prescriptive additions of 1,000 square feet or less, and CF1R-NCB-01-E covers newly constructed buildings and additions over 1,000 square feet. Efficiency First California notes that the 2025 code requires load calculations and proper sizing for new heating and cooling systems even in additions.

Alterations

Remodels, window replacements, and HVAC changeouts can trigger the code for the parts being changed. The CEC publishes alteration forms such as CF1R-ALT-02-E for prescriptive alterations to space conditioning systems. Title 24 Calcs lists HVAC replacement, window replacement and lighting changes as common triggers for an alteration report.

The forms: CF1R, CF2R and CF3R

California's single-family compliance documents come in three families. Each one belongs to a different stage of the project.

CF1R: the certificate of compliance

The CF1R is what most people call the Title 24 report. It shows that the design meets the code, either through the prescriptive path or the performance path. It lists insulation levels, window performance, HVAC and water heating equipment, and any measures that need field verification. On 2025 forms, that list is titled "ECC Feature Summary." The CEC says a qualifying permit application should include a registered certificate of compliance.

CF2R: certificates of installation

Contractors complete CF2R forms to confirm what they installed. Examples on the CEC forms page include fenestration installation, insulation installation, roofing ventilation and radiant barriers, and electric-ready requirements.

CF3R: certificates of verification

When a measure needs testing, a certified rater fills out the CF3R after checking the work. Examples include the building air leakage test, quality insulation installation checks at the framing stage, and verification of existing conditions for alterations.

Prescriptive or performance path

There are two main ways to show compliance.

1. Prescriptive path. You meet a fixed list of requirements for insulation, windows, equipment and so on. It is simple and works well for small additions and alterations that follow the list.
2. Performance path. A consultant models the building in CEC-approved software and shows that its energy use meets the code budget. It allows trade-offs, such as better windows in exchange for less insulation in one area.

Title 24 Calcs notes that the performance path takes more detailed modeling than the prescriptive path, and that climate zone affects the work. It names Climate Zones 10 and 15 as more demanding than coastal zones.

HERS verification is now the ECC Program

For years, Californians heard "HERS testing" or "HERS verification." On January 1, 2026, the CEC replaced the HERS Program with the Energy Code Compliance (ECC) Program for field verification and diagnostic testing. The CEC describes it as a continuation with a new name and new administration, and the field testing work itself carries over.

How it works, according to the CEC:

1. The CF1R lists the measures that need field verification and diagnostic testing.
2. The installing contractor completes the installation forms, and an ECC-Rater tests the listed measures on site.
3. Results are recorded in an ECC-Provider's data registry.
4. If a test fails, the contractor must fix the feature or system until it passes.
5. The building department checks the registered documents before it closes the permit.

There is an exception for urgent alterations, such as an HVAC changeout when a system fails. In that case the certificates can be registered after work begins, but before the permit is finalized.

Raters who held HERS certifications are recognized as ECC-Raters, and many businesses still use "HERS" in their names. The whole-house HERS rating, a separate home energy score, stays in the HERS program. Title 24 also requires completed documents to be left in the home for the owner.

Key 2025 changes for single-family projects

Efficiency First California's contractor guide summarizes the changes most likely to affect a house project:

• Load calculations and proper equipment sizing for heating and cooling, even for new systems in additions
• Limits on backup electric resistance heat in heat pumps, with thermostat settings that block it above 35°F outdoors
• Heat pump water heaters as the baseline, even in additions, while gas water heaters can still replace existing gas units in alterations
• Exterior wall insulation of at least R-15 in 2x4 walls or R-21 in 2x6 walls, with existing 2x4 walls holding at least R-11 left alone unless the project alters them
• An R-38 option for cathedral ceilings in all climate zones, or the performance path
• Stricter window U-factor and solar heat gain coefficient values in almost every climate zone, including like-for-like replacements

These items change what your architect specifies. A window package or water heater chosen under the 2022 rules may not pass under the 2025 rules.

What a Title 24 report costs

Published prices are scarce. Title 24 Calcs lists residential new construction and ADU reports starting at $250, with additions, alterations and commercial work quoted by scope. Its price includes the CF1R, registration with the data registry, plan-sized PDFs and revisions for plan check comments, and most residential reports take 1 to 2 business days once plans are complete. The same provider says registration fees can add $50 to $150 when another provider doesn't include them. Treat these as one company's prices, not a statewide average.

A report price may not cover the ECC-Rater's site visits for field testing. Ask for that quote along with the report, so the full compliance cost is in your budget.

Questions to ask before you hire someone for the report:

• Is the software updated for the 2025 Energy Code?
• Is data registry registration included?
• Are revisions for plan check comments included?
• Which measures will need ECC testing, and who arranges the rater?

You can estimate overall design fees, including energy work, with the calculator below.

How Title 24 fits the rest of your permit set

The energy forms are one part of the drawings the city reviews. Our page on permit drawings covers the rest of the set and how plan check works. If the project also changes the structure, see structural coordination. For project-specific guidance, read about ADU design, additions and remodels, residential design or commercial design, or return to the architecture overview.