Do I need Title 24 for a garage conversion that doesn't add new floor area?

Yes — in almost all cases. Even with no new square footage, converting a garage into living space turns previously unconditioned area into a conditioned dwelling space, and that triggers Title 24 under alteration rules. A registered CF1R is still prepared; the scope is just generally narrower than for new construction.

Why a conversion still triggers Title 24

A garage is unconditioned space. Turning it into living space means adding insulation, HVAC, a water heater, and lighting to a space that didn't have them — and each of those is a regulated energy system. The code applies to alterations, not just new floor area, so "no added square footage" does not exempt the project.

How conversion scope differs from new construction

The biggest practical differences from a new detached ADU are that solar usually does not apply and the envelope requirements are concentrated on the assemblies you actually alter — but the report itself is still required and still must be registered.

What to do for a conversion

1. Confirm the project address (this fixes the climate zone and code cycle).
2. Have the CF1R prepared under the alteration path for the systems you're adding or altering.
3. Make sure the HVAC, water heater, and lighting on the plans match the report.
4. Register the report and submit it with your permit set.

A common misconception is that "no new square footage" means "no energy report." The trigger is conditioning previously unconditioned space — which a garage conversion almost always does.

Because alteration edge cases (like-for-like swaps, very limited scopes) are jurisdiction-specific, the applicable code cycle and local amendments vary — confirm with your local building department. We prepare the registered CF1R under the correct alteration path as a +$240 Title 24 add-on alongside your MEP plans; see California ADU requirements or Title 24 Reports.