After-the-Fact Permits in California: What to Expect

6 min read · April 2026

An after-the-fact permit is the most common way to legalize unpermitted construction in California. But the process is not identical to a standard permit application — and it’s usually more expensive and more complicated. Here’s what you need to know before you start.

The Process, Step by Step

Step 1 — Pre-application meeting: Contact your building department and explain the situation. Many jurisdictions offer pre-application consultations to help you understand what’s required. This is the most important step — it sets expectations.

Step 2 — Plans and documentation: You’ll need plans showing the existing work. Depending on complexity, this may require a licensed architect or structural engineer. For simple work (a bathroom addition), a detailed sketch may suffice. For structural work, you’ll need engineered drawings.

Step 3 — Plan review: The building department reviews your plans against current code. They may require modifications. This is where after-the-fact permits differ most from standard permits — you’re checking existing work against current requirements, which may have changed since the work was done.

Step 4 — Inspection and corrections: An inspector examines the actual work. For hidden components (wiring, plumbing, framing), you may need to open walls. If work doesn’t meet code, corrections are required before final approval.

Step 5 — Final sign-off: Once everything passes, the permit is closed and the work is officially legalized.

What It Costs

Expect to pay 2–3x the standard permit fee as a penalty. Add plan preparation ($500–$5,000+), engineering if needed ($1,000–$10,000+), and any correction work. Total costs range from $1,000 for a simple project to $50,000+ for complex structural work.