ADU Permit Requirements in Los Angeles (2025 Guide): What You MUST Have Before Submitting

Building an Accessory Dwelling Unit (ADU) in Los Angeles is one of the best ways to add value, create rental income, or expand your property but the permitting process can feel overwhelming. LADBS has strict requirements, and even a single missing document can delay your project for weeks.

To help homeowners, architects, and developers avoid unnecessary corrections, here is the complete ADU permit requirements checklist you must follow in Los Angeles for a smooth approval process.

1. Complete Architectural Plan Set

Every ADU requires a full, detailed plan set that follows LADBS standards. This includes:

• Site plan with property lines, setbacks, and utility connections

• Floor plan

• Roof plan

• Exterior elevations

• Building sections & construction details

• Door & window schedules

Your plans must clearly identify the ADU as attached, detached, or garage conversion, as this affects zoning and structural requirements.

2. Zoning Compliance Review

Before submitting, verify your property meets zoning rules:

• ADUs are allowed on all R-zones and many non-residential zones

• Must follow setback regulations (generally 4 ft side/rear for detached ADUs)

• Maximum ADU size (typically 1,200 sq ft)

• Height limits, especially near property lines

• Parking requirements (may be waived if near public transit)

Failure to confirm zoning compliance is one of the most common rejection reasons at LADBS.

3. Structural Plans & Calculations

Structural documentation is required for all ADUs, especially:

• Second-story ADUs

• Garage conversions (raising ceilings, replacing slab, new beams)

• Additions to existing structures

• New construction ADUs

Your engineer must provide:
✔ Structural plans
✔ Calculations
✔ Shear wall layout
✔ Foundation details

All structural pages must coordinate perfectly with architectural plans.

4. Title 24 Energy Compliance

California mandates updated Title 24 energy calculations for all ADUs. These must match:

• Window sizes

• Insulation values

• Mechanical systems

• Roofing materials

Any mismatch between T-24 and the plans nearly always results in corrections.

5. Utility & Infrastructure Requirements

LADBS requires verification of utility connections, including:

• Electrical load calculations

• Plumbing layout (sewer & supply lines)

• Location of existing vs. new meters

• Gas line verification (if applicable)

For garage conversions, LADBS may require proof that the existing slab is structurally adequate or that it is being replaced.

6. Required LADBS Forms

Common forms needed for ADU approval include:

• Building permit application

• Plot plan checklist

• Agent authorization (if LWC is submitting for you)

• Owner-builder declaration (if applicable)

• Waste Management Plan (some jurisdictions)

Submitting incomplete or outdated forms is a frequent source of delays.

7. Clearances From Other Agencies

Based on location, your ADU may require approval from:

• City Planning (zoning review)

• Public Works (sewer capacity)

• Fire Department (setbacks, access roads)

• Housing Department (if rent-controlled property)

• Sanitation (utility verification)

Not all ADUs need every clearance but missing the required ones will stop your permit.

8. Digital Submission Requirements

LADBS requires plan files to meet strict digital formatting:

• PDFs must be flattened

• All pages correctly labeled

• Files combined in the correct order

• Size limits adhered to

• Separate uploads for T-24, structural, and specialized reports

Incorrect file formatting is one of the top reasons non-expediters struggle with ADU submissions.

Why ADU Permitting Is Complicated in Los Angeles

Los Angeles is one of the busiest permitting jurisdictions in the U.S., and ADUs have their own unique rules. A proper submittal can cut your approval time by 2–6 weeks.

At Land Works Consulting, we handle the entire process so you don’t have to from zoning review to final approval.

Need Help Getting Your ADU Permit Approved Fast?

Our team specializes in helping homeowners, developers, and contractors get ADU permits approved without delays.

We handle:

✔ Full ADU permit submissions
✔ LADBS coordination & corrections
✔ Zoning and feasibility checks
✔ Utility verification
✔ Entitlements (if needed)
✔ Clearances from all agencies

Whether you’re building a new construction ADU, garage conversion, or attached ADU, we make the process fast and stress-free.

→ Contact Land Works Consulting today to get started with your ADU permit.