In most cases, yes — room additions in California that involve conditioned space, changes to the building envelope, or new HVAC work require a Title 24 energy compliance report as part of the permit process.
What triggers Title 24 for an addition?
When an addition creates new conditioned living space, it typically requires energy compliance documentation. This includes bedroom additions, living room expansions, sunroom additions, and any project where new walls, windows, insulation, or HVAC equipment are being installed. The specific threshold and requirements vary by jurisdiction and project scope. Our guide to when Title 24 is required covers the common triggers and exceptions.
What if my addition is small?
Smaller additions may have different compliance pathways depending on local jurisdiction and the scope of energy-related work involved. Some building departments allow simpler compliance approaches for minor additions, while others require a full CF1R regardless of size. When in doubt, check with your local building department — or contact us and we can advise based on your project description.
How an Addition Is Modeled
There are two common ways to show an addition complies. The prescriptive approach checks each new component — insulation, windows, HVAC — against the listed requirements for your climate zone. It is often used for smaller additions and is documented on a prescriptive additions form (CF1R-ADD-01 in recent cycles; form names can change between code cycles).
The performance approach models the design in CEC-approved software. An addition can be modeled on its own, or together with the existing house. Modeling them together lets upgrades to the existing home — new windows, a more efficient system, added attic insulation — help offset features of the addition that fall short. We explain how this works in Title 24 calculations, and the result is documented on a CF1R.
What to Upload for an Addition
- A floor plan that clearly separates existing and new areas
- Elevations and a window schedule for new windows and doors
- Wall, roof and floor construction for the new area
- How the addition will be heated and cooled — extended ducts from the existing system, a new system, or a ductless heat pump
The heating and cooling choice matters. Extending or replacing ducts can bring in duct sealing and field verification by a HERS rater; see HERS rater vs Title 24 report. The full checklist is in what documents to upload.
How much does a Title 24 report cost for an addition?
Most residential additions fall under the Residential Report tier, starting at $245. Smaller ADU-scale additions may qualify for the ADU Report at $199. Contact us if you are unsure which tier applies to your project, or see our home addition Title 24 service and pricing.
Frequently Asked Questions
Does an addition need solar panels?
Usually not. The solar PV requirement is aimed mainly at newly constructed homes, and additions generally have exceptions. The report confirms what applies to your project under the current Title 24 requirements.
Is a garage conversion treated as an addition?
A garage conversion turns unconditioned space into living space, so it is handled much like an addition. See do garage conversions require Title 24.
Does an unheated porch or patio cover need a report?
Unconditioned structures usually do not need energy compliance, but the building department makes the final call based on your scope.