Short answer: In most cases, yes. Converting a garage into an ADU, a bedroom or other living space creates new conditioned space, and that triggers the Title 24 Part 6 Energy Code. Building departments usually require a Title 24 energy compliance report (a CF1R) with the permit application. Your local building department confirms what your project needs.
In most cases, yes. Converting a garage to an ADU or habitable living space in California requires a Title 24 energy compliance report. Because the conversion creates new conditioned living space, it triggers energy compliance requirements under Title 24 Part 6.
Why a Garage Conversion Triggers Title 24
A garage is unconditioned space. It is not heated or cooled, and it is usually built without insulation. When you convert it to a room people live in, it becomes conditioned space, and the Energy Code applies to it the same way it applies to new living space. The report shows that the converted space meets insulation, window and HVAC requirements. These elements are almost always upgraded during a conversion, since garages are uninsulated and unconditioned by design.
Title 24 is about energy. Structural, fire and zoning questions (parking replacement, setbacks, egress) are handled separately by the building and planning departments.
What the Report Looks At in a Garage Conversion
Every conversion is different, but the same areas come up on almost every project. The detailed rules are in the garage conversion Title 24 requirements.
Walls and ceiling insulation
Garage walls and ceilings are usually open framing or bare drywall. The conversion generally adds insulation to the exterior walls, the ceiling or roof, and any wall shared with the main house if that side is not conditioned. The required levels depend on your climate zone and compliance path. See garage conversion insulation requirements.
Slab floor
Most garages sit on an uninsulated concrete slab, often lower than the house floor. The report records the slab as it will be finished. Some projects add a raised floor or slab edge insulation, and others model the existing slab as-is. The model shows which option works for your design.
Garage door opening and windows
The garage door is usually replaced with an insulated wall, often with a new window or entry door. Every new window is entered with its rated U-factor and SHGC. See garage conversion window requirements.
Heating, cooling and water heating
The new space needs a way to be heated and cooled, whether by extending the home's existing system or adding a separate one, such as a ductless heat pump. If ducts are extended or new equipment is installed, the report may flag items for HERS field verification. See garage conversion HVAC requirements. A garage-to-ADU project also usually needs its own water heating, which the report covers too.
Garage-to-ADU vs. Garage-to-Bedroom or Addition
The energy work is similar, but the purpose of the space changes how the project is permitted and documented:
- Garage to ADU: the converted garage becomes a separate dwelling unit with its own kitchen and bathroom. It is permitted as an ADU and modeled as its own unit, and ADU streamlining rules may apply to the permit. For how compliance works across ADU types, see ADU Title 24 energy compliance.
- Garage to bedroom, family room or office: the space becomes part of the main house. In energy terms it is usually treated like an addition, and it can be modeled alone or together with the existing home. See home addition Title 24.
In both cases the climate zone for your address sets the energy budget. Your zone is listed on our California climate zones page.
Does Every Garage Conversion Require One?
Requirements vary by jurisdiction and by how much of the existing structure is altered. Some jurisdictions have specific allowances under ADU streamlining laws, but a Title 24 energy compliance report is required in the vast majority of garage-to-ADU conversions. A project that only makes cosmetic changes to a garage that stays unconditioned is generally not affected.
If you are unsure whether your project needs one, contact your local building department, or reach out to us and we can help you understand what is typically required.
How to Get a Garage Conversion Title 24 Report
Title24Comply prepares a garage conversion Title 24 report from your plans, starting at $199. Standard turnaround is 2–3 business days, and rush options are available. You order online, upload your plans as a PDF and receive a permit-ready report by email, with two revisions included. See what documents to send.
Frequently Asked Questions
Does a garage conversion need solar panels?
Often not, but it depends on the project. Conversions of existing space are frequently treated differently from newly constructed homes, and the report determines whether solar applies. See garage conversion solar requirements.
Can I keep the existing slab floor?
Often yes. The existing slab is entered in the energy model, and the rest of the design has to make up for it where needed. Whether that works depends on your climate zone and the other features.
Will a HERS rater need to visit?
Possibly. If the report flags items such as duct leakage or ventilation for field verification, a HERS rater tests them after installation. The CF1R lists any items that need it.
Does a detached garage conversion differ from an attached one?
The energy analysis is similar. An attached garage converted into part of the house is usually handled like an addition, while a detached garage converted into an ADU is modeled as its own unit.