Garage Conversion in Santa Ana, CA: Cost, Permits & Rules (2026)

A garage conversion is usually the lowest-cost path to an ADU in Santa Ana — $75,000-$170,000, versus $130,000-$300,000 for a new detached build — because the shell already exists.

Garage Conversion Cost in Santa Ana

Converting an existing garage in Santa Ana runs $75,000-$170,000. That's well under the $130,000-$300,000 typical cost of a ground-up detached ADU, because you're reusing the foundation, walls, and roof. The biggest variables are whether the slab and framing are sound, what utility/electrical upgrades are needed, and your finish level. Permit fees add REPLACE THE GUESS WITH PUBLISHED FIGURES. Planning Division FY 2026-2027 Fee Schedule: Accessory Dwelling Unit Review $1,940.00; ADU Over-the-Counter Review $594.00; ADU Pre-Approved Plan Review $524.00. Certain applications also carry a 7% technology fee per transaction, and from July 1, 2026 a 2.5% credit/debit card processing fee. These are PLANNING fees only — building permit fees are additional and the city does not publish them ('Building permit fees vary according to the scope of work'; Permit Counter (714) 647-5800).. A converted unit rents for about $1,700-$2,300/mo (1BR) in Santa Ana.

The Santa Ana Garage Conversion Permit Process

A garage-to-ADU conversion in Santa Ana needs building permits even if the exterior is unchanged. Approval process: Correct, and worth enriching: the Executive Director of the Planning and Building Agency (or designee) reviews and approves or denies ministerial ADU/JADU permits once the application is complete, conforming, and the non-refundable review fee is paid. WARNING WORTH SURFACING: applications that are incomplete or not in full conformance are REJECTED, not corrected in review. A denial is appealed as a minor exception under Article V. An over-the-counter track exists (its own $594 fee). The review timeline is 60 days, with plan check: Standard city review. Pre-approved plans: WRONG — THE PROGRAM IS LIVE. 10 free downloadable pre-approved plan sets for DETACHED ADUs: 3 studio (Ranch, Spanish, Traditional), 6 one-bedroom (Ranch, Spanish, Traditional, Contemporary by Design Path Studio; Craftsman and Spanish by James Gartner & Associates), 1 two-bedroom (Contemporary). Each downloads as a ZIP with the required submittal documents. Planning fee drops to $524 vs $1,940 standard, and the city says an over-the-counter submittal 'may be approved in as little as one day.' ELIGIBILITY LIMITS: property must have a single-family dwelling; NOT in flood zone A or AE; NOT in a historic district; NOT in Heninger Park; must meet grading permit exemption requirements. Requires a recent title report (within 6 months) and a pre-submittal consultation via planning@santa-ana.org..

1. Confirm eligibility — ADUs are allowed in TOO NARROW — CORRECT THIS. 'ADUs and JADUs may be permitted in all zoning districts where residential or mixed-use development is permitted.' That reaches beyond R1/R2/R3 to R4 (Suburban Apartment), mixed-use districts, and Specific Plan / Specific Development areas. MORE GENEROUS than we publish..
2. Prepare conversion plans — layout, egress windows, insulation, ventilation, smoke/CO detectors, plus a kitchen and bathroom.
3. Submit for plan check — Standard city review.
4. Pull permits and build — fees run REPLACE THE GUESS WITH PUBLISHED FIGURES. Planning Division FY 2026-2027 Fee Schedule: Accessory Dwelling Unit Review $1,940.00; ADU Over-the-Counter Review $594.00; ADU Pre-Approved Plan Review $524.00. Certain applications also carry a 7% technology fee per transaction, and from July 1, 2026 a 2.5% credit/debit card processing fee. These are PLANNING fees only — building permit fees are additional and the city does not publish them ('Building permit fees vary according to the scope of work'; Permit Counter (714) 647-5800).; then framing, electrical, plumbing, and final inspection.

No Replacement Parking Required

No. California law (AB 68 / Gov Code §66314) prohibits cities from requiring replacement parking when you convert or demolish a garage to build an ADU — so you do not need to add a parking space anywhere on the lot. Owner-occupancy: Keep the substance, ADD the conflict flag. ADU: no owner-occupancy requirement anywhere in the code (matches Gov. Code 66315). JADU: Sec. 41-194.5 requires a recorded covenant for EVERY JADU with no exception, which is STRICTER than Gov. Code 66333(b) as amended by AB 1154 (owner-occupancy permissible only where the JADU shares sanitation). LIKELY PREEMPTED as to JADUs with their own bathroom — but the city has not amended the code, so expect to be asked for the covenant.

The JADU Option for an Attached Garage

If your garage is attached to the house, you can convert it into a junior ADU (JADU) — capped at 500 sq ft (adopts the state maximum). Must be contained entirely within the living area of a single-family residence and have independent exterior access. and built within the existing walls. JADUs are cheaper and faster to permit than a full ADU, though they may share sanitation with the main home. A full ADU gives you more size and a separate unit; a JADU is the budget route.

Santa Ana Garage Conversion FAQ