ADU in Coastal Zone Permit Process

What It Really Takes to Permit a “Simple” Garage Conversion in the Coastal Zone (Los Angeles)

This project involved a partial garage conversion, converting one garage stall into a 404 SF studio ADU, while retaining the remaining portion as a functional two-car garage. On paper, this is considered a relatively simple project. In reality—especially within the LA Coastal Zone—the permitting process is anything but simple.

Initial Submittal: LADBS & ePlan

The process begins with Building & Safety plan check review through the LADBS ePlan online portal. Plans are submitted digitally and first go through a quality control screening, where LADBS verifies that all required documents and information are included.

The submittal package includes:

• Permit application with a detailed scope of work

• Architect and owner contact information

• Property and site information

• Full plan set prepared to LADBS standards

Once the plans pass initial screening, they are placed in the plan check queue. Typically, 1–2 weeks later, LADBS issues:

• Plan checker comments (questions, clarifications, or missing items)

• A Clearance Worksheet, outlining all required inter-departmental approvals

With an experienced architect, this stage is usually straightforward. Missing notes, code clarifications, or minor drawing adjustments are common. However, this is also where cheap or inexperienced drafters often cause major delays, requiring multiple rounds of revisions even for simple projects.

Agency Clearances: More Than You’d Expect

For this project, the required agency clearances ultimately included:

• City Planning

• Bureau of Engineering (BOE)

• LA Department of Transportation (LADOT)

• Bureau of Street Services (StreetsLA)

Not all of these were required at the outset. Additional clearances were added as reviews progressed—something that happens frequently and unpredictably.

Bureau of Engineering (BOE)

We started with BOE, as it’s typically the easiest to clear.

BOE required:

• Address approval
  In this case, the property had an older, unused address previously assigned, which we were able to reinstate. Other ADUs may receive a new house number or a “½” designation, depending on BOE’s determination.

• Sewer availability clearance
  BOE completed this review internally and approved it without issue.

LADOT → StreetsLA → Back to BOE

LADOT reviewed the project and required the driveway and curb cut to be narrowed, limiting access strictly to the remaining garage.

This single requirement triggered:

• A new Bureau of Street Services clearance

• An additional BOE review

We then had to prepare civil details showing:

• Sidewalk extension

• Narrowed curb cut

• Modified driveway geometry

Additionally, StreetsLA required a Trees in Parkway Permit.
There are no trees anywhere near this site, which is immediately obvious from Google Street View, but an application was still required. We submitted the permit, and it was approved within about a week after StreetsLA agreed with our findings.

City Planning & the Coastal Zone (The Big One)

City Planning is often the most complex clearance, especially in the Coastal Zone.

This project required:

• Coastal Development Permit (CDP) review

• Mello Act compliance, which is required when adding or removing a dwelling unit in the Coastal Zone

The Mello Act submittal is extensive and includes:

• Separate application forms

• Full plan set

• Grant deed

• Notarized documents

• Site photos with a photo index

All of this must be:

• Printed

• Physically delivered to the Planning office

• Accompanied by a USB drive with digital files

This is particularly frustrating given that every other department operates fully online through ePlan. One planner even noted they do not have access to ePlan themselves—an explanation that highlights just how outdated and fragmented the process still is.

Adding to the complexity, there has recently been confusion within City Planning about whether certain projects should be routed directly to the Coastal Commission versus staying within Planning. Not all staff are aligned, which creates uncertainty even for seasoned professionals.

Timeline & Takeaways

• Initial submittal: November 6

• Permit approval with all clearances: Early January

Key takeaways:

• The process is somewhat intuitive—but only if you’ve done it many times before.

• Each department has its own applications, requirements, and review timelines.

• Many submittals feel redundant across agencies.

• If the architect or applicant does not actively push each clearance forward, projects can easily sit in limbo.

• There is no centralized guidance—you’re expected to know what each department wants, similar to navigating the DMV without a checklist.

Sometimes you’ll work with knowledgeable, responsive staff who genuinely help move things forward. Other times, you’ll encounter exactly what everyone fears: an unhelpful reviewer who treats your project as a burden rather than a responsibility.

Final Thoughts

The permitting process in Los Angeles—especially within the Coastal Zone—feels archaic for the 21st century. Whether the solution is AI, better inter-departmental coordination, or a streamlined approval framework, something clearly needs to change.

Until then, experience matters. Even a “simple” garage conversion can become complicated quickly without someone who knows how to navigate the system.