15 Title 24 Mistakes That Trigger Plan Check Corrections
The fifteen mistakes that commonly send Title 24 documents back from plan check, why each one happens, and what to do before submittal so it does not happen to you.
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Most Title 24 corrections are not about whether a design is efficient enough. They are about documents that do not agree: two parts of the same submittal describing different buildings, or a certificate missing a signature or a registration. These are fifteen mistakes that commonly send a project back, with why each happens and how to prevent it. If a correction letter has already arrived, the response guides are the place to go: houses, ADUs, multifamily and commercial.
1. Preparing the report to the wrong code edition
Why it happens. A report started before 2026, or reused from an earlier permit, was prepared under the previous edition. The code that applies is the one in force on the date the permit was applied for, and a permit that expired with no construction under it resets to the code in force on the new application date.
How to avoid it. Confirm your application date before the report is prepared, and check that the certificate's standards version reads 2025 for any application submitted on or after 1 January 2026.
2. A project name or address that differs from the plans
Why it happens. The project was renamed, a lot was split, or the report used a mailing address. The Energy Code requires the name and location on the certificate to be consistent with the plans.
How to avoid it. Use the address exactly as it appears on the permit application and title sheet, and change both together.
3. The wrong climate zone
Why it happens. The zone was taken from a ZIP code. Some ZIP codes span more than one climate region, and the local jurisdiction can choose which zone applies across the ZIP.
How to avoid it. Look up the street address in the Energy Commission's climate zone tool, and ask the building department whether it has designated a zone for your ZIP code. See California climate zones.
4. The wrong form or project scope
Why it happens. The project was classified incorrectly. A garage converted to living space is an addition, existing conditioned space converted to an ADU is an alteration, and a new detached ADU is new construction. Additions, alterations and HVAC changeouts each have their own prescriptive forms.
How to avoid it. Agree the classification with your designer first, then check the project scope line in the certificate's general information.
5. Plans and certificate that describe different buildings
Why it happens. The drawings kept moving after the report was run: a room grew, an assembly changed, insulation was revised. The plan checker compares the CF1R with the plans, and any difference becomes a comment.
How to avoid it. Run the final report against the drawing set you submit, then compare conditioned floor area, assemblies and insulation values side by side.
6. A window schedule out of step with the report
Why it happens. Window sizes, counts or products changed, or the schedule on the drawings shows no U-factor and SHGC at all. The plan checker looks for the CF1R values on the window schedule.
How to avoid it. Put the CF1R's U-factor and SHGC on the window schedule, and check sizes and counts line by line. Window replacements follow the same rule.
7. HVAC and water heating details missing from the drawings
Why it happens. The mechanical information exists only in the report. The plan checker expects the efficiencies and system details from the CF1R, such as SEER2, EER2 and AFUE, to appear on the plans.
How to avoid it. Add an equipment schedule to the plans with the same model data and efficiencies as the certificate.
8. ECC-verified measures nobody accounted for
Why it happens. The report took credit for something that must be field-verified, such as a higher-efficiency system or a verified duct design, and the drawings do not show it. Or the scope triggers verification, as an HVAC changeout triggers duct testing, and nobody planned for it.
How to avoid it. Read the ECC feature summary, note each measure on the plans, and make sure the CF1R is registered so the ECC-Rater can work from it.
9. Special features left off the drawings
Why it happens. Features such as ducts in a crawlspace, a radiant barrier or zonal control were assumed in the model but never drawn. They need the inspector's attention, and the inspector works from the plans.
How to avoid it. Copy every special feature onto the relevant sheet with a clear note.
10. Mandatory measures overlooked
Why it happens. Mandatory measures apply whichever compliance approach is used, and compliance software may not check them automatically, so a passing result can hide a missing one.
How to avoid it. Include the mandatory requirements summary with the plans, and check the items that depend on drawings, such as ventilation, thermostats and minimum insulation.
11. Existing conditions assumed without a basis
Why it happens. In an addition or alteration, existing walls, windows or ducts were entered as better than they are, or with no record of where the values came from, and the plan checker may ask.
How to avoid it. Where nothing is known, use the defaults based on the year of construction. Where the condition is known, record how; an ECC-Rater can verify existing conditions for alterations.
12. Solar left off a project that needs it
Why it happens. The project is a new home or a new detached ADU, and the solar requirement in section 150.1(c)14 was missed, or an exception was assumed without being documented.
How to avoid it. Confirm early whether the requirement applies and which exception, if any, is used. For a new detached ADU the panels do not have to sit on the ADU itself. See Does an ADU need solar?
13. An unsigned or unregistered certificate
Why it happens. The CF1R needs signatures from the documentation author and the responsible person. Where registration is required, both are electronic, and the plan checker accepts only a registered copy that displays its registration number. A signing invite sits unanswered, or a draft is printed and submitted.
How to avoid it. Before submittal, check the declarations page for both signatures and the footer for the registration number.
14. The certificate in a format the department does not accept
Why it happens. Building departments differ. Some want the CF1R printed on plan sheets at full size; others accept sheets attached to the set, or letter-size printouts.
How to avoid it. Ask the department how it wants energy documents submitted, and request the report in that form.
15. Scope changes that never reach the report
Why it happens. A cheaper window, a different heat pump or another insulation product goes in after approval. A field change that affects compliance needs revised plans and revised energy documentation approved by the building department, and the mismatch surfaces at inspection or when the ECC-Rater compares the installed equipment with the registered CF1R.
How to avoid it. Send substitutions to your designer and energy consultant before ordering anything, and resubmit if the documents change.
The pattern behind most of these
Mistakes 2 to 9 share a cause: the certificate and the drawings drifting apart. One careful side-by-side check of the CF1R against the plan set before submittal catches most of them. The guide to reading your CF1R shows where each value sits. If corrections arrive anyway, Title24.Pro revisions are unlimited until the project complies.
More Title 24 Guides
- What Every California Homeowner Should Know About Title 24
- 12 Things to Know Before Ordering a Title 24 Report
- Title 24 Checklist: What to Have Ready Before You Order
- How to Read Your CF1R, Page by Page
- How to Choose a Title 24 Consultant
Frequently Asked Questions
The plan checker compares the CF1R with the drawings, so any disagreement, such as a window schedule, an equipment schedule or a floor area that no longer matches the certificate, becomes a comment. Missing signatures or registration, and designs that do not comply, are the other usual causes.
Where registration is required, the certificate submitted at plan check must be a registered copy showing its registration number. The exception is the HVAC changeout form, CF1R-ALT-02-E: if the enforcement agency approves, the registered copy can be presented to the inspector at final inspection instead.
Not if the code edition has changed. A fresh application after a permit expired unused is checked against the edition current on the day you reapply, so the report would have to be prepared again. If the edition and the design are both unchanged, the report still describes the project.