Short answer: Yes, in most cases. Accessory dwelling units in California must meet the Title 24 Part 6 Energy Code, and building departments usually require a Title 24 energy compliance report (a CF1R) with the ADU permit application. This applies to new detached and attached ADUs and to garage-to-ADU conversions. Junior ADUs built inside existing living space may have little or no energy scope. Your building department makes the final call.
Accessory dwelling units, whether detached, attached or converted from a garage, generally require a Title 24 energy compliance report in California as part of the building permit process. This applies to new ADU construction and to conversions that change the building envelope, insulation or HVAC.
Do ADUs Require Title 24?
An ADU is a home, so the residential energy standards in Title 24 Part 6 apply to it the same way they apply to a single-family house. Any ADU that creates new conditioned space, either by building it or by converting unconditioned space such as a garage, has to show that it meets the Energy Code. For the specific measures the code covers, see Title 24 requirements.
California ADU Energy Compliance by ADU Type
How the report is prepared depends on what kind of ADU you are building.
Detached ADU
A new detached ADU is treated as newly constructed residential space. The whole unit is modeled: walls, roof, floor, windows, heating and cooling, water heating and ventilation. Because it is new construction, solar PV requirements may also apply (see the FAQ below).
Attached ADU
An attached ADU shares a wall or floor with the main house. In energy terms it is usually handled like an addition, so the ADU can be modeled on its own, or together with the existing home when that gives a better result. The existing house generally does not need to be upgraded, unless its systems are altered as part of the work. For more on additions, see home addition Title 24.
Garage conversion ADU
Converting an attached or detached garage turns unconditioned space into living space, which triggers energy compliance. Garages are usually uninsulated and have a slab floor and a large door opening, so the report focuses on the new insulation, windows, the infilled door opening and the new heating and cooling system. See do garage conversions require Title 24, or order a garage conversion Title 24 report.
Junior ADU (JADU)
A JADU is created within the walls of an existing single-family home. If it uses space that is already conditioned and the work does not add windows or change heating and cooling equipment, there may be little or no energy scope. If it converts unconditioned space, such as part of an attached garage, or includes new HVAC or water heating, energy documentation is usually needed. Ask your building department.
What Type of Report Does an ADU Need?
The report for an ADU is a CF1R (Certificate of Compliance for residential buildings). ADU projects follow the Title 24 Part 6 residential energy standards. Most ADUs use the performance method, where the design is modeled in CEC-approved software and compared with a code-defined standard design for the same climate zone. The specific requirements depend on the project scope, the building type and your climate zone, which is set by the project address. The energy analyst models the compliance path that fits the project.
The CF1R also lists any items that need field verification by a HERS rater after installation, such as duct leakage or ventilation. See what a HERS rater does.
How Much Does an ADU Title 24 Report Cost?
A Title24Comply ADU Title 24 report starts at $199 for up to 1,000 sq ft, plus $9 per 100 sq ft beyond that. CHEERS registration where the project requires it, a permit-ready PDF by email and two revisions are included. The final price follows the square footage on the plans. If an adjustment is needed, we contact you before we start. See Title 24 report cost for details.
How Fast Can I Get It?
Standard turnaround is 2–3 business days after we receive complete plans. A 24-hour rush is available for +$49 on ADU reports. Same-day Super Rush (+$150) is available for urgent projects, so contact us to confirm availability. See rush and same-day service and which documents to upload.
Frequently Asked Questions
Does an ADU need solar in California?
It depends. Newly constructed detached ADUs can be subject to the solar PV requirements that apply to new homes, but there are exceptions, and attached ADUs and conversions of existing space are often treated differently. The Title 24 report determines whether solar applies to your project and, if it does, what the system has to provide.
Does the ADU need a heat pump?
The 2022 and 2025 code cycles emphasize heat pumps and electric-ready measures, and heat pumps often make compliance easier. What is required for your ADU depends on the compliance path and climate zone, and the report will show it.
Can I order before my ADU plans are final?
Yes. Many clients order with near-final plans. If the design changes, two revisions are included. See using preliminary plans.
Is the ADU report different from a report for a new house?
The forms and the modeling method are the same. Only the scope is smaller, which is why ADU pricing starts lower.