Yes, you can, and it needs a building permit. Most garage conversions in California go through the accessory dwelling unit (ADU) rules, which are friendlier to homeowners than older zoning. State guidance says no replacement parking is required when a garage is converted to an ADU, and no setback is required for an existing garage. If you want the full picture on ADUs first, start with Zermit's ADU permit requirements guide.

What Does State Law Say?

California's housing department publishes guidelines for garage conversions. They note that a bathroom is required, a structural engineer may be required to examine the garage, and the project must meet fire safety, electrical capacity and other utility requirements. The guidance also makes clear that the finished space has to meet current building code.

How Long Will the City Take?

State law sets a clock. A city must approve or deny a complete ADU application within 60 days, and if it does not, the application is deemed approved. Newer legislation also tightened the completeness review to 15 business days. Review speed in practice depends on how complete your drawings are, and Zermit's Los Angeles ADU approval timelines guide and how long a building permit takes in Los Angeles show what to expect locally.

What Does Los Angeles Add?

The City of Los Angeles follows state law and adds its own review through LADBS. City Planning documents note that no setback is required for an existing garage converted to an ADU, and the ADU must have independent exterior access. Parking is generally not required for the garage you convert, though ADUs can have separate parking rules in other situations, so confirm with the city.

If your property is in unincorporated Los Angeles County, a different office applies. The County publishes standard notes for garage conversions and warns that failure to submit the required items can lead to automatic denial of the permit application. The County also states that solar panels are not required for an existing single-story garage conversion. Our required documents guide for Los Angeles ADUs and the common mistakes guide can help you avoid that kind of rejection.

What Will It Cost?

Costs vary widely. The state's guidance says that if the garage is in sound condition, a conversion typically costs less than new construction, with a starting price that will probably be upwards of $100,000. That guidance has aged, so treat the figure as a floor and get current local quotes. Permit fees are only one part of that total, and the Los Angeles ADU permit costs guide and building permit costs and fees explain how to estimate them.

What If My Garage Was Never Permitted?

Many older garages were built or altered without permits. If yours was, expect to document the structure and bring it up to code as part of the conversion. Skipping the permit is the riskier path, as our posts on renovating without a permit in California and why permits matter for resale value explain.

Who Will You Need on Your Team?

A garage conversion usually involves several trades. A designer or architect prepares the drawings, a general contractor manages the build, and electricians, plumbers and HVAC technicians handle the systems. Zermit's Find a Pro directory lists architects and building designers, general contractors, electrical professionals, plumbers and HVAC and mechanical contractors.

Finishing touches matter too. Converted garages typically need new openings and an enclosed front wall, so window contractors, door dealers and garage door contractors may be part of the job.

A Simple Checklist Before You Start

Confirm your jurisdiction, whether City or County. Have a designer or engineer assess the slab, framing and electrical capacity. Decide whether you want an ADU or a junior ADU, and review the Los Angeles ADU requirements. Then prepare complete drawings, since incomplete submissions are a common source of delays.

Where Zermit Fits

A full garage conversion is a plan-review project, so work with an architect or ADU designer for the main permit. Zermit AI is an AI-powered permit platform for over-the-counter and like-to-like residential permits. The smaller electrical and plumbing permits that follow can often be handled at app.zermit.ai, and the Los Angeles ADU inspections guide explains what inspectors check.

FAQs

Do I need to replace the parking I lose?
Under state guidance, no replacement parking is required for a garage converted to an ADU. Check your local rules for any related requirements.

Can I rent out a converted garage?
Generally yes once it is a permitted ADU, though local rules on short-term rentals and owner occupancy can apply.

Do I need an engineer?
The state notes a structural engineer may be required to examine the garage. Your designer or the city will tell you if yours does.