Every homeowner who wants to develop an ADU will have different needs and a different approach to the project. If it is your first time building an ADU, we encourage you to work with an experienced contractor and with the Department of Building & Safety to answer any questions.

The ADU Process

Below is an overview of the ADU process for you to browse about how to build an ADU in Los Angeles. The overall timeline to build an ADU ranges from 12-18 months depending on the complexity of your project and your contractor’s speed and experience. While simpler than other construction projects, ADUs still require time, financing, and design and building expertise. To breeze through the permit and inspection processes, we encourage you and your contractor to stay up-to-date on the latest policies and regulations.

Getting Started

Understand the basics.

  • Identify the primary purpose of your ADU. Are you looking to house an elderly parent? Help build more affordable housing in Los Angeles?
  • Understand what you are allowed to build, and what an appropriate budget will be by learning the basics of ADUs.
Determine Eligibility

Find out if your property is eligible for building an ADU.

Timeline: 10 minutes
  1. Use ZIMAS to find out if your lot is in an eligible zone to build an ADU. You can also download this tutorial here.
    1. Find your lot by searching your address and selecting the correct address.

    2. This is the ZIMAS viewport. On the left hand side, take note of these fields in these sections:
      1. Planning & Zoning: Zone, Hillside Area Zone

    • You can build an ADU if:
      You are located on a property in a single-family or multi-family zone with an existing or proposed single-family home (this generally includes “R” zones, such as “R1,””RE,” “RA,” and “RS”). For multi-family zones, ADUs can only be constructed as an accessory second unit on the lot; properties with existing duplex, apartment or condominium buildings are not eligible to build an ADU.
      Additional limitations may apply to the construction of your ADU if:
      1. Your lot is located in a Very High Fire Hazard Severity Zone and/or a designated Hillside Area. However, some exceptions may apply. Contact LADBS to confirm what requirements apply to your property.
    • After this initial self-screening, discuss your project with your architect, contractor, or go in-person to one of the City of Los Angeles’ Development Services Centers (no appointment necessary) to confirm that your property is eligible to build an ADU and to understand any additional requirements you may need to adhere to based on your location or property characteristics (e.g., properties in a Historic Preservation Overlay Zone (HPOZ) must be reviewed by staff and potentially the HPOZ Board for consistency with the district’s Preservation Plan; properties in designated Hillside Areas may have additional considerations regarding access or construction requirements).
Construction Plans

Hire a team to develop construction plans.

Timeline: 4-8 weeks
  • Hire a draftsman or architect who has experience designing ADUs to build construction plans. A great place to find a licensed architect is on AIA’s Member Directory.
  • Share your vision with your designer so they can create a plan that addresses your needs.
  • Make sure you develop a communication plan with your designer so you receive regular updates on the progress of your project. This is important to ensure that your project fulfills your vision and stays on track.
  • If you intend to convert an existing, detached accessory structure on your property, please ensure that you carefully review the LADBS Information Bulletin entitled “Accessory Dwelling Unit Conversion of Existing Detached Structure” so that your construction plans are drafted accordingly.

Tip: Check out our section on site requirements, including lot size, building height, setbacks, and easements that will need to be reflected in your construction plans.


Determine your budget, secure financing, and explore other incentive options.

Timeline: varies (minimum 2 weeks)
  • Having adequate financing is essential to paying for all the costs associated with your ADU, including construction and permit fees. Here are some financing options you can consider for your unit.

Obtain required permits and clearances from the City.

Timeline: varies (1 day - 6 months)
  • Construction of your ADU is dependent on receiving all required permits and clearances from the City. It is essential to start the permit application process early. After you have determined your site’s eligibility, assessed applicable code requirements, and developed your plans, stop at the public counter at one of the City of Los Angeles Development Services Centers to submit your detailed construction plans and a building permit application (no appointment necessary). There are several Development Services Centers throughout the City,but the Metro (Downtown) DSC, which is located in Downtown Los Angeles, offers the most services (though not all are needed for ADU approval). The Metro (Downtown) DSC is located at 201 and 221 N. Figueroa St.
  • Plans are reviewed at LADBS within the following turn-around time based on type of service:
    • For straight-forward, one-story conversion or new construction projects, you may qualify for:
      1. Same day service, up to 1 hour wait time for Counter Plan Check
      2. Same day service, up to 2-3 hours wait time for Expanded Plan Check
    • For more complex projects, such as second story additions, new 2-story detached structures, or projects in hillside grading areas, plans will need to be assessed via regular plan check. For this process, your engineer will be assigned within 5-6 weeks OR within 3-4 weeks if you choose to pay an expedited fee (50% of your building permit fee).
  • Once plan check is completed, the following will be provided:
    1. A correction list and instructions
    2. A clearance summary worksheet, listing all relevant agencies which must approve the work
  • Bring your clearance summary worksheet to all departments listed on the worksheet to obtain clearances & pay fees to different departments. Follow instructions as noted in the Clearance Summary Worksheet and reference the addresses and contact information listed for each Development Services Department.
  • Once all corrections have been made on the plans and all clearances have been obtained,
    1. Plans will be approved and stamped
    2. Permit(s) will be issued
    3. Construction can begin

Tip: Depending on the scope of your project, you may require additional clearances from other City departments, including the Department of Water and Power and the Department of City Planning. Check our City Department Contact List section to learn more about each department’s role in the ADU process.

Tip: Permit fees can add up! Use this calculator to estimate your permit cost.


Work with a contractor and pass all required inspections.

Timeline: 3-12 months

Hiring a Contractor:
  • To construct your ADU, we highly recommend hiring a contractor. Common places to find contractors are
    1. Department of Consumer Affairs Contractors State License Board
    2. Referrals from architects, designers, friends, and neighbors
  • Receive cost estimates from your contractor and decide on a contractor to work with. Check our helpful tips on working with contractors.

Tip: Vetting your contractor is important to ensure they have experience building an ADU, have worked in the City of LA, and understand the permit process.

Passing Inspections:
  • Once construction begins, you must call LADBS to schedule an initial inspection to ensure that your unit is being constructed according to plans. Make an appointment online or call the customer service number, (213) 473-3231.
  • When your ADU is completed, you must call LADBS for one final inspection.

Tip: There are several points in the ADU process that will require an inspection. Confer with your contractors and LADBS to ensure you are aware and prepared. Passing your inspections is crucial to building your ADU in a timely and hassle-free manner.

  • Call for an inspection at least 24 hours in advance. Occasionally office workloads delay inspections an additional 24 hours.
  • If you pass: You may continue to build your ADU until it is completed
  • If you don't pass: Make sure your contractor addresses the identified issues, then call DBS for a second inspection.
Certificate of Occupancy

Your ADU is ready for tenants!

Timeline: 2-3 weeks
  • If you have passed the final inspection, the City will issue you a Certificate of Occupancy (CofO).
  • A Certificate of Occupancy certifies a building’s compliance with applicable building codes and other laws, and indicates it to be in a condition suitable for occupancy. An ADU may not be rented or inhabited without a CofO. The CofO may be mailed and can be found online in LADBS’ Permit & Inspection Report.

Site Regulations

While rear property setback requirements are standards for ADUs, other requirements like parking, building height, and side setbacks can vary by the type of ADU you build. For specific requirements based on your type of ADU, refer to Types of ADUs.

Lot Size

Check whether your lot is eligible.

There is no minimum required lot size to build an ADU, as long as the ADU meets the required property pedestrian setbacks (outlined below). However, be sure to confirm that your lot is located in a zone that is ADU-eligible. ADUs must be located in residential zones, and most likely single-family residential zones.

Building Height

Abide by local height restrictions.

In general, your ADU may not be higher than two levels. However, check with your local building code to ensure that you abide by local height restrictions, especially if you want to build an ADU above a garage.

Parking Regulations

Determine whether you must build new parking spots.

Parking is important in Los Angeles. Current rules require that parking be added in some circumstances in order to ensure that neighborhoods have ample parking for residents. However, you do not need to provide parking for attached ADUs or interior conversions. You are also exempt from parking requirements if your property is located within a 0.5 mile radius of public transportation.

  • You DO NOT need to provide parking if you are converting a garage or are within located within a 0.5 mile radius of public transportation.
  • ADU Conversions:
    If you are converting your garage (and thus displacing your parking spots), you need to maintain the two parking spaces allotted to your primary home. If space is tight on your lot you may add parking space in an added driveway, and parking can be tandem.
Property Setbacks

Abide by property setback regulations.

Setbacks are the required space between your structure and the property line. Setbacks are necessary to ensure fire safety and to allow for proper light and air access between you and your neighbors. Setback requirements vary based on the type of ADU you build. Most ADUs built in Los Angeles follow a required 5 feet from the rear property lines and minimum 10 feet from other main structures, like the primary home.

ADU and 5' rear setback and 10' setback from primary dwelling

Abide by easement restrictions.

There are a variety of easements: LADWP specific, Public Utilities, Owner, and even sewer easements. Proposed ADUs cannot block access to LADWP facilities, which include easements, power lines, poles and underground equipment. Following these regulations is essential to ensuring safety, as construction near power poles, wires, and other equipment without the proper distances can lead to serious risks. All ADUs, new or conversions, within ten feet of LADWP easements, facilities, or overhead power lines require approval from LADWP (this process can take 1-6 months.) Read more about LADWP’s ADU regulations here. You can also check on ZIMAS to see what kind of easement you have.


Appropriately financing your ADU is essential to ensuring the success of your project. ADU building costs will vary based on the type and design. It is important to thoughtfully finance your ADU and ensure you have allotted extra funds for unforeseen costs. Banks and other types of financial institutions are now lending to homeowners interested in building ADUs and offer homeowners a variety of financing options. As with all financing, it is advisable to be deliberate and conservative in your decision-making.


Use cash from your savings.

Financing your ADU with all cash eliminates the need to pay interest on a loan or any closing costs. However, it is important that you retain sufficient liquidity for unforeseen maintenance or vacancy and consider the tax implications of your decision.

Cash Refinancing

Replace your mortgage with a new home loan.

Cash refinancing replaces your mortgage with a new home loan with a higher balance than what you currently owe on your home. The difference between what is owed on the mortgage and the home’s value goes to the borrower. An important thing to note is that equity must be built on the home in order to use this option.

Construction Loans

Finance your ADU construction costs.

Construction loans generally pay for plans, permits and fees, labor and materials, and closing costs. Construction loans take into consideration the appraised improved home value once construction is done, instead of the current home value.

Home Equity Loans

Borrow against your home's value.

A home equity loan allows homeowners to borrow against their home’s value minus what is owed on the mortgage. Home equity loans typically provide a fixed amount of cash with a fixed repayment schedule using your property as collateral.

Home Equity Line of Credit (HELOCS)

Use your property as collateral.

HELOCS are backed by your home’s equity and use your property as collateral, but are structured as revolving lines of credit. They typically have shorter repayment terms, and charge interest only on the amount drawn from the line of credit.

Investments/Retirement Accounts

Utilize money from your retirement and investment accounts.

Homeowners can use cash from retirement and investment accounts to finance their ADUs, but there may be fees or early withdrawal penalties associated with these types of accounts.

Savings Account

Utilize your personal savings.

Savings is one of the best ways to pay for your ADU. While most homeowners cannot completely rely on their savings to finance their ADUs, all homeowners who are interested in building an ADU should have some cash to cover upfront expenses such as design/architecture expenses and permitting fees. It is also important for homeowners to add a contingency to their budget to cover any expense overruns.

Personal Line of Credit

Obtain a personal line of credit from your bank.

Banks often offer borrowers a personal line of credit if they have good credit scores and sufficient income.

Questions to Ask the Los Angeles Department of Building & Safety

Make sure to ask these questions before leaving the check-in counter.

  1. What is my lot's Residential Floor Area (RFA)?
  2. What are my setbacks?
  3. Can I build an ADU?
  4. What is the expected turnaround time to get my ADU approved?
  5. Does my project need to be submitted?
  6. What is the maximum building height I'm allowed to build?
  7. What is the maximum # of stories I'm allowed to build?
  8. Do I need to hire an engineer?
Questions to Consider with My Family

Make sure to consult with your family before embarking on your ADU build process.

  1. Is now a good time to take on a construction project?
  2. Am I prepared to manage multiple vendors to ensure they adhere with my desires and timelines?
  3. Do I have access to enough cash to complete the project or am I eligible for financing?
  4. What if my plan for the project goes over budget or timeline?
  5. Do I know anyone who has built an ADU and can help me?
Hiring a Contractor

Make sure that you work with a reliable and experienced contractor.

  1. Before hiring contractors visit State of California Consumer Affairs to help you select the right professional for your project.
  2. Make sure you understand all the details of bids and the tradeoffs between cost and your contractor's level of experience before making a decision.
  3. Verify your contractor's license using the Contractors State License Board and request an insurance certificate by calling their agent.
  4. Note that California law requires that no more than 10% of the total construction cost be paid upfront.