California ADU Permitting: What Every Homeowner Needs to Know

Understanding California's ADU Permitting Process

California has passed some of the most homeowner-friendly ADU legislation in the country. Since 2020, state laws have significantly reduced barriers to ADU construction — limiting fees, removing parking requirements in many cases, and forcing cities to approve compliant ADU applications within 60 days.

Despite these reforms, navigating the permitting process still requires expertise. Here's what you need to know.

What Permits Are Required?

Building an ADU in California typically requires the following approvals:

• Building permit — structural, electrical, plumbing, and mechanical
• Planning/zoning approval — confirms the ADU complies with your city's development code
• Fire department review — required in many jurisdictions for new structures
• Title 24 energy compliance — California's mandatory energy efficiency standards
• Utility connections — separate utility meters for detached ADUs may require permits from your utility provider

How Long Does Permitting Take?

Under California law, cities must act on a complete ADU permit application within 60 days. In practice, timelines vary:

• Los Angeles County unincorporated areas: 8–14 weeks
• City of Los Angeles: 10–16 weeks (LADBS)
• Smaller cities (Glendale, Pasadena, Burbank): 6–12 weeks

Delays most commonly occur when applications are incomplete or when design documents don't meet local requirements. Working with an experienced ADU contractor who knows each city's specific preferences dramatically reduces revision cycles.

Common Permitting Mistakes

Submitting incomplete plans. Every city requires a specific set of drawings — site plan, floor plans, elevations, structural calculations, Title 24 reports. Missing even one document triggers a correction notice and restarts the clock.

Ignoring setback requirements. ADUs must maintain minimum distances from property lines, the main house, and other structures. These vary by city and lot configuration.

Underestimating utility work. Adding a new dwelling unit often requires upgrading your electrical panel, adding a new water meter, or upgrading the sewer lateral. These are permitted separately and can add cost and time if not planned for upfront.

Using unpermitted existing structures. Converting an unpermitted garage or room addition into an ADU requires first bringing the existing structure up to code — a process that can be more expensive than starting fresh.

Why the 60-Day Rule Matters

Since 2020, California law requires cities to approve or deny ADU applications within 60 days of receiving a complete application. If the city fails to act, the application is deemed approved by operation of law.

This is a powerful protection for homeowners — but only if your application is complete and correctly submitted. LEE Enterprises handles the entire application process, tracking deadlines and following up with building departments on your behalf.

Our Permit Approval Record

LEE Enterprises has a 100% permit approval rate across all completed ADU projects in Southern California. We've successfully permitted ADUs in Los Angeles, Glendale, Burbank, Pasadena, Van Nuys, Sherman Oaks, Encino, Thousand Oaks, Simi Valley, and dozens of other jurisdictions.

Get Started

Permitting is the part of ADU construction that most homeowners find most intimidating — and it's the part we handle entirely for you. Call 818-223-1125 or request a free consultation to learn how we'll manage your permit from start to finish.