The Permitting Process for ADUs in California
Permitting is one of the most important—and often misunderstood—parts of building an accessory dwelling unit (ADU). California has streamlined many ADU rules in recent years, but permits are still required to ensure safety, compliance, and proper construction. At MF ADU, we help homeowners understand the permitting process early so projects move forward smoothly and without unnecessary delays.
Why ADU Permits Are Required
Permits ensure that your ADU meets building codes, zoning regulations, and safety standards. Cities review plans to confirm structural integrity, fire safety, utility connections, and proper placement on the property.
Although permitting may feel complex, it protects homeowners and ensures long-term value.
Preparing Plans for Submission
Before permits can be issued, detailed plans must be submitted to the local building department. These typically include:
Site plans showing placement and setbacks
Architectural layouts and elevations
Structural and engineering details
Utility connection plans
Accurate and complete plans reduce the risk of corrections that can slow approvals.
Plan Review and City Feedback
Once submitted, the city reviews your plans for compliance. This step may include comments or requests for clarification.
Responding promptly and accurately to city feedback is key to keeping the process on track. Experienced ADU teams help address these comments efficiently to avoid repeated reviews.
Permit Approval and Inspections
After plan approval, building permits are issued and construction can begin. During construction, inspections are scheduled at key stages to verify that work meets approved plans and code requirements.
Inspections are a normal part of the process and help ensure quality and safety throughout the build.
Why Experience Matters in Permitting
While California law supports ADU development, local interpretation still matters. Cities may have specific documentation requirements or review procedures.
Working with an experienced ADU provider helps prevent common permitting mistakes, reduces resubmissions, and keeps timelines predictable.
Did you know?
Did you know? Many ADU permitting delays happen due to incomplete plan submissions—not because ADUs are restricted under California law.
Move Through Permitting with MF ADU
The permitting process doesn’t have to slow your project down. At MF ADU, we guide homeowners through each step—from plan preparation to final approvals—so nothing is overlooked and momentum is maintained.
If you’re ready to discuss your project or have questions about permits, connect with us through our contact page.
Frequently Asked Questions
Do I need permits to build an ADU in California?
Yes. Permits are required to ensure compliance with building and safety codes.
How long does the ADU permitting process take?
Timelines vary by city, but complete and accurate plans help speed up approvals.
Can permits be denied for an ADU?
Cities must allow ADUs under state law, but designs may need adjustments to meet requirements.
Are inspections required during ADU construction?
Yes. Inspections are required at different construction stages.
Does MF ADU help with the permitting process?
Yes. We assist with plan coordination and guide homeowners through approvals.