How Much Does an ADU Permit Cost in Los Angeles?

Building an accessory dwelling unit (ADU) in Los Angeles starts long before the first nail is hammered. It begins with getting the right permits.

Permit costs for a Los Angeles ADU can range anywhere from $5,000 to over $20,000, depending on your design, property location, and the type of ADU you plan to build.

Understanding how much it costs to permit an ADU upfront helps homeowners avoid delays, budget surprises, and compliance issues down the road.

In this guide, we'll explain everything you need to know, including:

• The key components that make up ADU permit costs in Los Angeles.
• How your ADU type (garage conversion ADU or detached ADU) affects permit pricing.
• What to expect from the permitting timeline and approval process.
• Why the average cost can vary between the City of LA and unincorporated LA County.
• How LADU simplifies the entire permitting process with one team and one contract.

By the end, you'll know exactly what impacts ADU permit cost in California, how to plan for it, and how LADU's ADU building permit services can help manage the process from start to finish, saving you time, money, and stress.

Contact LADU today to get a free consultation and learn what permits your property will require.

What Is an ADU Permit? Everything You Need To Know

Legal Requirement for Construction

Before you start building an ADU in Los Angeles, you'll need a permit to build the proposed ADU. California law mandates a valid building permit for all accessory dwelling units (ADUs), whether you're converting a garage or constructing a new detached unit.

Skipping this step can lead to serious consequences, including stop-work orders, fines, and, in extreme cases, mandatory demolition of the unpermitted structure. An ADU permit is not optional; it's your legal permission to build and occupy a secondary unit on your property.

What an ADU Building Permit Covers

ADU permits are not a single document. They're a collection of approvals granted from the Los Angeles Department of Building and Safety (LADBS) that ensure your project complies with local and state codes. Typical permits involved in an ADU project include:

• Zoning Permit: Verifies that your property is eligible for an ADU and that your plans meet local zoning rules for size, setbacks, and height.
• Plan Check: Covers the review of architectural and structural drawings to confirm code compliance.
• Building Permit: Authorizes the construction and includes required inspections throughout the build.
• Mechanical, Electrical, and Plumbing (MEP) Permits: Ensure that all utility systems are installed safely and to code.

These permits help protect your investment and ensure your ADU is safe, legal, and insurable.

LADU Secures ADU Building Permits for You

At LADU, we understand that dealing with city agencies and permit paperwork can be overwhelming. That's why our in-house permitting team manages the entire process for you, from ADU design and preliminary zoning checks to final permit issuance.

We coordinate directly with the building department, submit complete drawing sets, and handle revisions so you don't have to. With LADU, you get peace of mind knowing your project is moving forward legally and efficiently.

Breaking Down ADU Permit Cost in Los Angeles

Since every ADU is unique, it's hard to predict the exact permit costs in Los Angeles, as they vary from project to project, but a skilled ADU builder, like LADU, will handle the entire process for you and keep you informed about individual costs along the way.

General Cost Range

So, how much do ADU permits cost in Los Angeles? The short answer is that it depends. Most homeowners can expect the total cost of an ADU permit in California to fall between $5,000 and $20,000+, depending on the size and complexity of the ADU.

Smaller ADUs or simpler projects, like a garage conversion, tend to fall on the lower end, while larger detached units or two-story designs usually cost more due to additional reviews and inspections.

Key Cost Categories

To better understand the total cost of the ADU permit, it helps to break it down into three main categories:

• Plan Check Fees: These fees cover the city's review of your submitted plans and typically range from $500 to $5,000. The more complex your design, the higher the plan check fee.
• Building Permit Fees: These are charged based on the valuation of the construction and can range from $450 to over $15,000. They include site inspections and final occupancy approval.
• Zoning Fees: Depending on your city and any special zoning overlays (like hillside or coastal zones), these fees can range from $30–$500 but sometimes can be as much as $4,000. In some areas, zoning fees are bundled with building permits. In other cases, a separate zoning permit will be needed.

Additional Permit Fees and Related Expenses

The costs of architectural and structural plan designs, zoning permit fees, building permit fees, impact fees, and other fees and taxes all factor into the final accessory dwelling unit permit cost.

Besides the fees you would expect to probably have to pay, other costs that may impact your final permit cost in Los Angeles include:

• Title 24 Energy Reports: Required by the state to ensure your ADU meets energy efficiency standards.
• MEP Permits: Separate permits for mechanical, electrical, and plumbing systems.
• Development Taxes: Some jurisdictions charge impact or development fees, though these are often waived or reduced for ADUs under 750 sq. ft.

Factors That Affect ADU Permit Cost

When you're planning to build an ADU in LA, it's important to understand that permit fees can vary based on several factors.

ADU Type and Design Complexity

The type of ADU you build plays a major role in determining permit costs:

• Garage Conversions: Typically the least expensive to permit, ranging from $1,000 to $10,000 in permit fees. These projects often require fewer structural changes.
• Detached ADUs: Fully separate units usually require the most comprehensive plan reviews and inspections, which can push permit fees toward the higher end of the spectrum.

Square Footage and Scope

The size of the ADU matters. Larger units often require more complex drawings, energy calculations, and structural reviews. For example, a two-story, 1,000 sq. ft. detached ADU will likely incur higher permit costs than a 400 sq. ft. garage conversion.

Location and Jurisdiction

Permit fees and requirements can vary significantly depending on whether your property is in the City of Los Angeles or unincorporated LA County. For example, LA County may require approvals from additional agencies such as Public Works or the fire department, which can add time and cost.

Timeline: How Long Does It Take To Get an Accessory Dwelling Unit Permit?

Average Permit Timeline

The average timeline to obtain ADU building permits in Los Angeles ranges from 8 to 24 weeks. This depends on the complexity of your design, the responsiveness of local agencies, and whether any plan corrections are required.

Steps in the Process

Securing a permit to build an ADU involves several stages:

1. Pre-Check: LADU evaluates your site for zoning compliance and feasibility.
2. Plan Submittal: Complete drawings are submitted to the city.
3. Plan Check: City reviewers evaluate your plans for code compliance.
4. Corrections: If needed, LADU revises and resubmits plans.
5. Approval: Once plans are accepted, fees are paid.
6. Permit Issuance: Construction permits are issued and work can begin.

LADU's Advantage in Speeding up Approval

LADU's architect-led approach means we submit complete, code-compliant packages from the start, thus reducing delays and minimizing costly resubmissions. Our team knows what local agencies look for, helping your project move through plan check faster.

What Happens if You Build an ADU Without a Permit?

Legal and Financial Risks

Building without an accessory dwelling unit permit is risky. If discovered, the city can issue stop-work orders and even require you to tear down the unpermitted structure. Fines and fees may also be imposed. These penalties often cost more than the permit fees would have.

Future Property Sale Issues

Unpermitted ADUs can complicate selling or refinancing your home. Lenders may not recognize the value of the unit, and buyers may be hesitant to take on the legal risk. A permitted ADU adds legitimate value to your property.

LADU Helps You Stay Compliant

Our team ensures every ADU we design is fully permitted and documented. From the first site visit to final inspection, LADU makes sure your project complies with all local and state requirements.

How LADU Makes Navigating ADU Permits Simple

One Team, One Contract

With LADU, you're working with one team under one contract for ADU design, permitting, and construction arrangements. This integrated approach avoids delays, miscommunication, and added costs that can come from juggling multiple vendors.

Architect-Led Design for Faster Approvals

Our in-house architects are experts in California ADU codes and local zoning rules. That means smarter layouts, fewer corrections, and faster approvals from the building department.

Fixed Pricing. No Surprises.

We offer flat-fee design packages and guaranteed construction pricing when you choose to work with one of our licensed construction partners. That means you'll know your ADU permit cost and total project budget upfront, with no surprise invoices or scope creep.

How To Budget for ADU Permit Costs

Start With a Site Assessment

The best way to understand your potential ADU permit cost in Los Angeles is by scheduling a free site assessment with LADU. We'll evaluate your property's zoning, setbacks, and utility access to give you a clear picture of what's possible.

Plan for Design + Permit + Construction

Permit fees are just one part of your total ADU budget. LADU helps you plan for the full scope, from architectural design and permitting to arranging for the construction phase. With our all-in-one model, you'll never be caught off guard by hidden costs.

Financing Options Available

LADU partners with financing providers that allow you to spread out the cost of your ADU project, including permit fees. This makes it easier to move forward with confidence, even if you're not paying everything upfront.

Ready To Start Your ADU Project?

ADU permit costs in Los Angeles can be significant, but with the right guidance, they're manageable. From plan check fees to zoning permits, understanding your total permit cost helps you budget smarter and avoid delays.

LADU makes the process simple. With fixed pricing, in-house architects, and a full-service model, we take the guesswork out of building an ADU.

Schedule your free site evaluation today to understand your ADU permit cost and start your project with confidence.

Start Your ADU Project With Confidence

Understanding the ADU permit cost in Los Angeles is a crucial step toward building a legal, safe, and value-adding accessory dwelling unit.

From plan check fees and building permits to zoning reviews and development taxes, the full cost of an accessory dwelling unit permit can vary widely depending on your project's size, complexity, and location.

With the right partner, navigating these details doesn't have to be overwhelming.

LADU simplifies every step of the process. Our architect-led team handles everything, from zoning analysis and plan submittals to fast-track approvals and arranging for ADU construction.

We offer fixed pricing with no surprises so that you can budget with confidence and avoid unexpected permit fees or project delays.

Whether you're converting a garage or building a detached ADU in your backyard, LADU brings local code expertise and a proven process to get your plans approved faster.

We've helped homeowners across Los Angeles understand how much ADU permits cost and how to manage those expenses without stress.

Talk to an ADU expert today to schedule your free consultation and get a clear, personalized breakdown of your permit costs and start your project off right.

Common Questions About ADU Permits

Do I Need a Permit for a Garage Conversion?

Yes. Even if you're converting an existing structure, you'll need full ADU building permits. This includes plan check, building, and utility permits to ensure the space is safe and code-compliant.

Are There Fee Waivers for Affordable Housing?

Some cities offer reduced or waived permit fees for ADUs designated as affordable housing. LADU can help you determine if your project qualifies and guide you through the application process.

How Can I Avoid Delays?

Work with an experienced team like LADU that knows how to prepare complete, compliant submittals. Our familiarity with local codes and agency expectations helps speed up approvals and minimize revisions.