Title 24 energy compliance glossary

Plain-language terms for your plans, report and construction handoffs. Educational information, not legal advice: confirm project classification, application date and requirements with your authority having jurisdiction (AHJ).

CF1R

A residential Certificate of Compliance describing the proposed design and its applicable Energy Code compliance path. It is design documentation, not proof that equipment has been installed or field verified.

Read the CF1R guidance

CF2R

A residential Certificate of Installation used for applicable installed measures. The responsible installer documents the work; a design-phase report alone does not replace this handoff.

Read the CF2R guidance

CF3R

A residential Certificate of Verification for measures requiring independent verification. Required verification and its documentation are separate from our design-report preparation.

Read the CF3R guidance

NRCC

Nonresidential Certificates of Compliance document the proposed design for applicable commercial building systems. The project scope determines which certificates are needed, rather than one universal package for every tenant improvement.

Read the NRCC guidance

NRCI

Nonresidential Certificates of Installation record applicable installed measures. They are a construction-stage responsibility distinct from preparing design-phase NRCC documents.

Read the NRCI guidance

NRCA

Nonresidential Certificates of Acceptance document required acceptance testing for applicable systems. Acceptance testing is separate from our report-preparation service.

Read the NRCA guidance

ECC

Energy Code Compliance is the CEC program framing used for applicable verification under the 2025 Energy Code. Required field verification is separate from the design documents Title 24 Lab prepares.

Read the ECC guidance

HERS (legacy terminology)

Older-cycle documents may refer to the Home Energy Rating System program and HERS verification. Do not simply relabel an older report; confirm the applicable edition and verification program.

Read the HERS (legacy terminology) guidance

LSC — Long-term System Cost

A metric used in applicable 2025 Energy Code performance comparisons, not a prediction of a household’s utility bill. Older reports may use time-dependent valuation (TDV); those older metrics and thresholds should not be transplanted into a current report.

Read the LSC — Long-term System Cost guidance

Reach code

A local requirement that goes beyond statewide Energy Code provisions within its applicable scope. Confirm current approved provisions and application-date rules with the AHJ rather than assuming every city has the same extra requirements.

Read the Reach code guidance

Performance approach

An approved modeling approach comparing the proposed design with applicable compliance budgets while retaining mandatory requirements. It is not a blanket waiver of individual requirements or a permit-approval promise.

Read the Performance approach guidance

Prescriptive approach

A compliance path using the applicable prescribed measures for the project instead of relying on modeled trade-offs. Project type, edition and scope determine the measures and documentation.

Read the Prescriptive approach guidance

Conditioned floor area

Floor area associated with heated or cooled space, which may differ from gross area shown on a title block. Identify conditioned and unconditioned areas on the plans and have the modeler confirm the scope before a pricing tier is final.

Read the Conditioned floor area guidance