Can a HERS Index score show Title 24 compliance?

No. California compliance is shown on a certificate of compliance produced with Energy Commission-approved software, and the 2025 Energy Code does not use the HERS Index.

Were HERS raters renamed ECC-Raters?

For Title 24 testing, the job moved: California HERS raters were recognised as ECC-Raters on 1 January 2026. A RESNET-certified rater who produces HERS Index scores holds a separate national credential, unrelated to the role the 2026 rename moved into the ECC Program.

Does California still have a HERS Program?

Yes, with a narrower scope. Since 1 January 2026 it covers whole house ratings and home energy audits under Title 20, and the Energy Commission is updating its rating and labelling rules.

Title 24 vs the HERS Index

A HERS Index score is a rating: RESNET puts a typical home built to 2006 standards at 100, and lower is better. Title 24 compliance is pass or fail against the 2025 code, and since 1 January 2026 California's own HERS Program covers only whole house ratings and home energy audits, not code compliance.

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Two different questions

Title 24 asks whether this design meets the code for its climate zone: every prescriptive requirement or, on the performance path, no more energy than the standard design the code builds for it. The answer is yes or no, and the certificate of compliance records it. A rating asks something else: how efficient is this home compared with a reference? The answer is a number on a scale, and a home can score well or badly on it without the code being involved.

RESNET's HERS Index is the best-known scale. A certified rater assesses the home and models it against a reference home of the same size and shape. A typical home built to 2006 energy efficiency standards scores 100. In RESNET's own examples, a score of 70 is 30 per cent more efficient than a standard new home and a score of 130 is 30 per cent less efficient.

Three things called HERS

The HERS Index. A national scale run by RESNET, a not-for-profit standards body accredited by ANSI. RESNET notes that some states and cities accept a HERS Index target as a performance option in their energy codes. The 2025 California Energy Code does not use the Index, although it does cite a RESNET test standard, ANSI/RESNET/ICC 380, for airtightness testing.
California's HERS Program. The Energy Commission's programme under Title 20, Sections 1670 to 1675. Since 1 January 2026 its scope is limited to whole house ratings and home energy audits, and in the Commission's words the remaining services "do not support Title 24 compliance". The Commission calls this rating side "HERS II".
The old name for code field verification. "HERS I", the testing that proves compliance, moved into the 2025 Energy Code as the ECC Program. HERS raters became ECC-Raters on 1 January 2026; documents for earlier code cycles still say HERS. See the ECC Program and what an ECC-Rater does.

California's own rating scale

Public Resources Code section 25942 directs the Energy Commission to set up a consistent, accurate and uniform home energy rating system on a single statewide scale for new and existing homes. The programme is voluntary and is meant to include estimates of bill savings and recommendations for cost-effective improvements. The procedures for California whole house ratings and home energy audits sit in the HERS Technical Manual, and the Commission has opened a rulemaking to update the Home Energy Rating and Labeling Program. A California whole house rating and a RESNET HERS Index score come from separate systems run by different bodies.

Where a rating and a Title 24 report touch

On some alterations they share a protocol. When a remodel's performance model takes credit for verified existing conditions, the 2025 Single-Family Compliance Manual has the ECC-Rater check them using the Whole-House Home Energy Rating protocols in the HERS Technical Manual. The registry then generates a CF3R-EXC-20-H, which must be registered before the project's CF1R can be. The ENERGY STAR programme for California homes also defines its Raters by their qualification to perform California HERS Ratings; see Title 24 vs ENERGY STAR.

Which one do you need?

For a permit, only the Title 24 documents count: the certificate of compliance and, where it calls for them, ECC field verification results. A rating is something an owner, builder or buyer chooses to commission. It can describe a home, but it cannot stand in for the compliance report.