Need to Legalize Unpermitted Work on Your California Property?

Work completed without a required permit is considered unpermitted, regardless of the quality of the work or how long ago it was done. It can affect a property sale, insurance coverage, financing, and can result in a code violation if discovered by the reviewing jurisdiction. Many situations can be addressed by pursuing a permit after the fact — see our guide on getting a permit for work that's already built.

In many cases, yes. California building departments generally have a process for this, sometimes called a retroactive, as-built, or legalization permit. For unpermitted ADUs and JADUs built before January 1, 2020 specifically, California Assembly Bill 2533 (Government Code Section 66311.7), effective January 1, 2025, created a streamlined statewide pathway. See our guide on retroactive building permits for more detail.

Legalization requirements generally attach to the property and the structure, not to who built it. If you discovered unpermitted work after purchasing, see our guide on buying a house with unpermitted work for what to do next.

Often, yes, though it can complicate the transaction — affecting buyer financing, appraisals, and disclosure requirements. See our guide on selling a house with unpermitted work for a general overview of what's typically involved.

This can happen through a neighbor complaint, a permit application for other work, or a routine inspection. It typically results in a notice requesting that the property owner either remove the unpermitted work or bring it into compliance through a permit. See our guide on what happens if the city discovers unpermitted work.

Often, yes — most permit applications for existing unpermitted work require drawings that document the structure as it currently exists, called as-built plans. Whether they're required, and what they need to show, depends on the project and reviewing department. See our as-built plans service page for more.

Not every situation can be resolved through legalization. Whether legalization is possible depends on the specific property, the structure or improvement, current zoning, applicable building codes, and the requirements of the reviewing jurisdiction. An individual review is needed to assess feasibility.

Whether licensed professionals are required depends on the type and scope of the project and the requirements of the reviewing department. Some projects require stamped plans from a licensed architect or structural calculations from a licensed engineer. Legal ADU Pro helps identify when such professionals may be needed and can help coordinate with them.

Timelines vary significantly depending on project complexity, the building department's current workload, and how prepared the documentation is at submittal. Some projects can be resolved relatively quickly; others take considerably longer. An individual review helps set realistic expectations.

Costs depend on the scope of the project, the professionals involved, applicable city and county fees, and other factors. Legal ADU Pro can help you understand the range of costs typically involved once your specific situation is reviewed.