Converting Your Garage Into an ADU? Start With the Right Plans and Permits
Haven't converted your garage yet? Here's how to plan and permit the conversion correctly from the beginning — rather than building first and legalizing it afterward.
Planning a Garage Conversion ADU From the Start
Converting a garage into an ADU is one of the more common ways California homeowners add living space — and doing it as a new, permitted project generally means understanding the requirements before construction begins, rather than after. This page is for homeowners who haven't started the conversion yet.
Legal ADU Pro helps homeowners understand what this type of project typically involves, coordinate plans and documentation, and connect with licensed professionals when required.
Why Start With Permits
- Avoids the added complexity of legalizing completed work after the fact
- Reduces the risk of having to undo or modify work that doesn't meet code
- Generally gives more clarity on requirements and costs before construction begins
- Can make the project easier to finance, insure, and eventually sell
General Process Overview
While every project and jurisdiction is different, planning a garage conversion ADU generally involves: an initial review of the garage and property, coordinating the plans and documentation the project needs, submitting for the appropriate permits, responding to any plan check corrections, and completing inspections during and after construction.
Because the project starts from an existing garage structure, plans typically need to account for its current condition — not just the intended new use.
Plan Your Garage Conversion ADU
Legal ADU Pro can help you understand what converting your garage the right way typically involves.
Request a Property Review →Explore planning options for detached, attached, and other new ADU projects.
View New ADU Services →If your garage was already converted without permits, this isn't the right page — see Garage Conversion Legalization instead.
Garage Conversion Legalization →Which Situation Are You In?
You're planning the conversion and want to understand plans and permits before construction begins. You're on the right page.
The work is already done and you need to bring it into compliance. See Garage Conversion Legalization instead.
Questions About Planning a Garage Conversion ADU
Starting with permits generally avoids the added complexity, cost, and uncertainty of legalizing work after the fact — including potential corrections to work that's already been completed. If your garage is already converted without permits, see our Garage Conversion Legalization service instead.
A garage conversion generally starts from an existing structure, which can affect the plans and documentation involved, compared to a detached ADU built on previously unused space. Both still require plans, permits, and often licensed professionals depending on scope.
Not necessarily. Feasibility depends on the property, zoning, the garage's current condition, and the requirements of the reviewing jurisdiction. An individual review is needed to understand what's realistic for your specific property.
Ready to Plan Your Garage Conversion ADU?
Request an initial property review and understand what converting your garage the right way typically involves.
Request a Property Review → Call 310-570-2885