Role of the Planning Department in ADU Approvals in California

Table of Contents

1. What is an ADU?

2. Why Build a Permitted ADU in California?

2.1 Benefits of a Permitted ADU

3. What Does the Planning Department Do in ADU Approvals?

3.1 Key Responsibilities of the Planning Department

4. Tips to Work Smoothly with the Planning Department

5. FAQ

What is an ADU?

An Accessory Dwelling Unit (ADU) is a secondary suites, self-contained residential structure located on the same lot as a primary single-family or multi-family home. Often called granny flats, in-law suites, or backyard cottages, ADUs offer independent living spaces. They can be attached, detached, or converted from existing areas like garages or basements. ADUs typically include a kitchen, bathroom, and separate entrance. They provide flexible housing options for family, guests, or rental income while maximizing property use.

Why Build a Permitted ADU in California?

Building an ADU with permits is essential to ensure your project is legal, safe, and aligned with current building and zoning regulations.

Benefits of a Permitted ADU:

✅ Boost Property Value
✅ Generate Legal Rental Income
✅ Stay Code-Compliant
✅ Avoid Future Legal Issues
✅ Access Financing or Refinancing Options

What Does the Planning Department Do in ADU Approvals?

The Planning Department is your first stop when proposing an ADU in California. They ensure your project complies with local zoning laws, design guidelines, and state ADU regulations.

Key Responsibilities of the Planning Department:

1. Zoning Review

The planning department checks if your property is eligible for an ADU under local and state zoning laws. They'll verify:

Zoning designation (R-1, R-2, etc.)
Lot size and width
Number of existing structures
Maximum number of ADUs allowed on the parcel

2. Development Standards Enforcement

Your ADU must comply with local development standards, including:

Setbacks (distance from property lines)
Height limitations
Square footage caps
Lot coverage percentages
Minimum open space

3. Design Review

Depending on the city or county, your ADU may be subject to architectural review for neighborhood compatibility. This includes:

Exterior finishes
Roof pitch
Window placement
Privacy concerns

4. Permit Intake & Routing

Once your ADU plans pass zoning and design checks, the planning department routes your application to the building and other departments (fire, utilities, etc.) for final review and approval.

5. Guidance on State ADU Laws

California’s ADU laws (like AB 68, AB 2221, and SB 9) override some local restrictions. Planning staff can clarify how state-mandated standards affect your project, such as:

Reduced setback requirements
Eliminated parking mandates
Streamlined approvals within 60 days

Check how to get an ADU permit in San Diego

Tips to Work Smoothly with the Planning Department

✅ Schedule a Pre-Application Meeting
✅ Submit Accurate & Complete Plans
✅ Hire an ADU-Experienced Designer or Architect
✅ Understand Local and State Laws
✅ Ask About Pre-Approved ADU Plans (if available)

Learn more about how to get an ADU permit in Bay Area

FAQ

Do I need to go through the planning department for every ADU?

Yes. Every ADU must go through planning review to ensure it complies with local zoning and development standards.

Can the planning department deny my ADU project?

They can only deny your project if it violates objective standards (e.g., lot size, setbacks). Under state law, discretionary denials are limited.

What happens after planning department approval?

Your project is forwarded to the building department for structural, mechanical, electrical, and fire code reviews.

How long does ADU planning approval take?

By law, cities must approve or deny ADU applications within 60 days, though delays may occur if plans are incomplete.

Can the planning department require design changes?

Yes, but only if local design standards apply and they are objective and uniformly applied.