Remodeling the House and Adding an ADU: How Many Title 24 Reports Do You Need?
The number of compliance documents follows the buildings and scopes, not the permit. A new detached ADU is a newly constructed building, an attached ADU or garage conversion is an addition, and work on the existing house is an alteration. The texts do not say whether one CF1R may cover both, so confirm with your building department.
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Sort each piece of work
- New detached ADU: a newly constructed building that meets the new single-family requirements, documented on the new-building certificate (CF1R-NCB-01).
- Attached ADU, or a garage or storage space converted: an addition under Section 150.2(a), on CF1R-ADD-01, or ADD-02 when no ECC verification is needed.
- Existing conditioned space converted: an alteration under Section 150.2(b).
- Work on the main house: new HVAC, windows, a water heater or insulation are alterations of regulated components, even when the ADU shares the permit.
Why the count is not fixed
The compliance manual says the length and complexity of the CF1R documentation depends on the number of buildings built or altered, the size of any addition, the approach used and whether an orientation-independent permit is sought. It does not say whether one certificate may cover two buildings, so the safe reading is one document set per building and scope, until the department says otherwise.
Where solar and battery-ready land
Solar PV is required for a newly constructed detached ADU unless an exception applies, and is not required for an attached ADU. New modules for the ADU may be added to the main house system on the same lot if they are part of the ADU permit application; existing panels cannot be counted. Battery-ready wiring applies to the new ADU unless its service is 125 amps or less. For a new ADU, ventilation and lighting rules carry no size exception. See adding ADU panels to the main house system and ADU battery-ready requirements.
Ordering
ADU reports start at $199 and residential reports at $245. Tell us every scope on the lot when you order so the documents are divided correctly; revisions are unlimited until the project complies. The house list is in remodel with new windows and HVAC.
Ask the department
Confirm whether it wants one set or two, which permit carries each, and who signs. Classification detail is on addition versus new construction, and the ADU CF1R page explains the document. Start at ADU Title 24 reports.
Common Title 24 Questions
- Do ADUs need Title 24 in California?
- What plans are needed for an ADU Title 24 report?
- How much does an ADU Title 24 report cost?
- How long does an ADU Title 24 report take?
- Does a garage conversion ADU need Title 24?
- Does a JADU need a Title 24 report?
Frequently Asked Questions
Expect one document set for each building and scope, and confirm with the department whether it accepts a single CF1R across both.
No. Each is classified on its own. The ADU follows its new, addition or alteration rules, and the house follows the alteration rules for the components it changes.
Explore Title 24 Reports
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- Remodeling a Condo: Title 24 for Unit Owners
View all Title 24 Reports guides → · Reports and Calculations · Title 24 guide