How long does it take to permit a garage conversion in California?

For a complete, well-coordinated application, California garage conversions generally move through permitting in a matter of weeks to a few months — driven far more by application completeness than by the building department's pace. State law sets meaningful guardrails for ADUs, but each correction round you trigger can quietly add weeks. Timelines vary by jurisdiction; confirm with your local building department.

The statutory timeline for ADUs

• 15-day completeness review — the department first checks that your submittal is complete. A complete package enters plan check; a missing piece bounces back before review even begins.
• 60-day decision window — state law obligates building departments to act on a complete ADU application within 60 days of submittal.
• Correction rounds — each round can add roughly two to six weeks while you revise, resubmit, and wait for re-review, and high-volume cities can stretch further.

The math is what makes completeness so valuable: a clean application can clear in well under the 60-day window, while two avoidable corrections can add a month or more to a project that should have moved straight through.

What slows a conversion specifically

1. Incomplete submittal — missing the registered CF1R, an MEP sheet, or a required form stalls the project at completeness review.
2. Uncoordinated disciplines — outlet, fixture, and equipment conflicts between the architectural, electrical, and plumbing sheets, or HVAC specs that don't match the energy report.
3. Service-upgrade utility timeline — if the panel needs upgrading, the utility's shutoff coordination runs separately from the permit and is often the longest pole.
4. Wrong Title 24 path — applying new-construction rules to an alteration, or the wrong climate zone.

The single biggest timeline factor is application completeness. A coordinated, complete submittal is what lets a conversion clear the 15-day completeness review and enter plan check without bouncing back.

How to keep the clock moving

• Submit a complete package the first time — coordinated MEP, registered CF1R, architectural/structural drawings, and forms.
• Use one team for mechanical, electrical, plumbing, and Title 24 to eliminate cross-discipline conflicts.
• Identify any service upgrade early so the utility timeline runs in parallel, not at the end.

On the plan-production side, our standard turnaround is 5 business days, with Priority at 3 days (+$299) and Express at 1-2 days (+$599) if your application clock is tight. Orders include two revisions plus city corrections, so correction rounds are handled without extra plan fees. See how it works or start your order.