City of Los Angeles ADU Rules & Regulations

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What is all the buzz about ADUs in Los Angeles? Want to learn about The City of Los Angeles ADU rules and regulations? An ADU is an Accessory Dwelling Unit (aka Granny Flat or a small home) that can be built in your backyard and used for extended family or friends or as a rental property. It can be attached or detached from the main house.

The State of California is leading the nation in ADU development and regulations, and the ADU handbook published by the State of California provides a great summary.

One of the most affordable types of ADUs is a prefabricated home. One of Los Angeles’s most active prefabricated ADU builders in Los Angeles is USModular Inc. “ADUs are becoming very popular for homeowners looking to generate rental income in their backyard or for families that have children or elderly parents moving home, as it gives everybody their own space, is affordable and ADU increases the value of the property,” says Todd Kesseler, CEO of USModular Inc.



Some of the Highlights of Los Angeles ADU Regulations:


ADU Min/Max Building Sizes

An attached accessory dwelling unit cannot exceed 50% of the primary residence, up to 1,200 square feet. For example, if your existing house is 2,500 sq. ft., the attached ADU cannot exceed 1,750 sq. ft. in size. The minimum size allowed is 150 square feet. If you are building a detached ADU, you can build up to 1,200 square feet regardless of the size of the main home. So even if you have an 800-square-foot house, you can still build a 1,200-square-foot ADU, assuming you are below your FAR requirement.


ADU Home Parking Requirements

If the garage is converted, homeowners must add one parking spot, which can be located anywhere on the property, including in a driveway or tandem.

  • Parking spaces must be 8 ½ ft. X 18 ft. Compact parking is not allowed.
  • Parking is NOT required if you live within half a mile of public transit.
  • Parking is NOT required if you live in a historic district.
  • Parking is NOT required if the accessory dwelling unit is part of an existing primary residence (for example, if you are converting an existing basement or another part of your home).

Parking is NOT required if you live within one block of a car share such as ZipCar or Turo.

Many lots in LA are within a half-mile of transit, so ADU parking may not be required. Check the City of Los Angeles transit map to see if public transportation is within walking distance of your home.

  • Check to see if your lot is within a half-mile radius of a bus stop, rail station, or dedicated space where a shared vehicle is parked.
  • You can call or visit the Department of Building and Safety website to confirm whether parking is needed.


ADU Setbacks

Any existing legal structure can be converted into an accessory dwelling unit. This is great for homeowners looking to maximize their garage! In fact, an existing permitted garage doesn’t have to comply with the new setback requirements.
For everything else, setbacks are 5’ from the side and rear of the property.


Home Owner/ADU Occupancy

There is no owner occupancy clause. This means the owner does not have to live in the primary residence or the accessory dwelling unit, meaning both units can be rental units.


ADU Rentals

California passed Senate Bill 1069 to increase the supply of housing in the state. For this reason, any accessory dwelling unit may be used for a long-term rental. The local government decides if short-term rentals are allowed.


How to Evaluate ADU ROI

Building an accessory dwelling unit, especially if you intend to keep the property for a few years, represents an enormously beneficial opportunity to maximize your property.
By constructing an accessory dwelling unit you are adding additional square footage to the property. So if you can build a unit for $300 a square foot, but the average value of homes in your neighborhood are worth $500 a square foot you are gaining instant equity through the project. Plus, you also now have the added benefit of a flexible space that can be rented or used for family.


City Of Los Angeles ADU Regulations Are Some Of The Most Progressive In The State Of California!


  • Los Angeles, CA, has a population of 4,054,400
  • Median property value: $ 689,500
  • Single-family properties: 645,902
  • Persons per household: 2.86
  • Median rental value: $ 4,071
  • Multi-family properties: 827,713

Based on Los Angeles’s population, the number of Single-Family Homes, Multifamily Properties and Rental Value, there is a lot of opportunity for ADU construction in Los Angeles.

City of Los Angeles Website for more information on ADUs & to Submit Your Building Plans
City of Los Angeles Pre-Approved ADU Plans
Official ordinance for the City of Los Angeles


What is Prefabricated Construction?


  • Prefabricated construction means homes are built off-site in a factory, just like your car and most of every other item you use daily.
  • Prefabricated Homes are also known as Manufactured Homes and Modular Homes. Several cities in the State of California have pre-approved prefabricated home plans.
  • These homes are designed, reviewed, approved and inspected by the State of California.
  • The main benefits of prefabricated ADU homes in Los Angeles, CA, are that they are less costly, faster to build in factories, and less impactful on homeowners and neighbors.


FAQ About ADUs in Los Angeles, CA


Here are the answers to common questions that Los Angeles homeowners ask when considering adding an accessory dwelling unit (ADU) to their property.


Does Los Angeles Zoning Allow ADUs In My Neighborhood?


In 2020 and 2021, new laws were passed, making it easier for Californians to build ADUs. Major changes to Los Angeles zoning regulations, permit requirements, and developmental standards went into effect, making it easier, faster and cheaper to build an ADU on your property.


How Many ADUs Can Los Angeles Homeowners Build on Their Property?


Los Angeles ADU rules allow one detached ADU and one junior ADU (a unit no more than 500 square feet located within the home) to be built on most single-family residential lots. If you live on a multifamily lot, you may be able to build two detached ADUs.


How Does USMODULAR Build ADUs?


We are prefabricated construction specialists. Our ADUs are built in a factory to ANSI – American National Building code (Tiny Homes), Federal/HUD building code (Manufactured Home) or CBC/Local Building code. We choose to build prefabricated construction as we have more control over the line and quality of construction. Also, prefabricated construction is less disruptive to residents of homes and neighborhoods as our time on site is minimal.


How Long Does Permitting an ADU Take in Los Angeles?


We recommend ordering your home while we are still in the permit phase to shorten the overall built time.


According to Los Angeles ADU Regulations, is a Parking Space Needed?


According to new state laws, an additional parking spot is not needed if the ADU is located within a half mile of a public bus stop or rail station, is on a street that requires on-street parking permits, but the permit has not been offered to the occupant of the ADU; or is located within one block of a public car-share program. If you do not meet this requirement – we will need to show space on your lot for ADU parking, and this can be on the existing driveway as a tandem space.


Are There Any Hidden Or Surprise Costs To Building An ADU In Los Angeles?


We offer all-inclusive pricing for standard ADU sites. If your lot has special circumstances (hillside, sewer pumps, septic, crane etc), we determine any additional fees charges for extra site work, upgrades, etc., with you upfront so you know your full cost to build an ADU in Los Angeles.


How Will An ADU Affect The Sale Price Of My Los Angeles Home?


An ADU can increase property value and boost the primary home’s price when it’s time to sell. However, many factors go into home prices, and every case is unique.


How Do I Know If An ADU Can Fit On My Property in Los Angeles?


Many properties can accommodate an ADU, and we offer ADUs ranging from 160 sq ft to 1,200 sq ft. Contact us for a free Virtual site assessment to determine if the property can fit an ADU.


How Does An ADU Access Sewer, Water And Electricity Lines?


In most cities, ADUs are allowed to connect to the primary home’s water, sewer, electricity and gas.


Can I Build An ADU On A Hillside in Los Angeles?


Cities often have special building regulations for hillside construction, and the feasibility of this type of construction must be determined on a case-by-case basis.


Does It Make Sense For Me To Build An ADU On My Property?


That is a question only you can answer, but we can provide a few reasons why it might be:

  • You need extra space for aging parents or kids, and it’s expensive for them to live in an apartment
  • You want extra income and have unused space on your property.
  • For example, in many areas of Southern California, a 2- or 3-bedroom apartment costs $2000 per month. If you finance a $200,000 ADU with a home refinance and use your home’s equity, the typical monthly payments on this loan are $900-$1000. Economically, this seems to make sense, as it can save family members on rent or help you earn money every month.


What is a Junior Accessory Dwelling Unit (JADU)?


A Junior Accessory Dwelling Unit (JADU) in Los Angeles is a dwelling unit with independent exterior access that is no more than 500 square feet in size and contained entirely within a single-family residence, including an attached garage. The proposed JADU or the existing single-family residence must be owner-occupied.


USModular Inc. is a premier contractor of prefabricated homes and ADUs with over 40 years of experience in the industry. You can see the available floor plans and pricing at
Toll-Free: (888) 987-6638
Local: (951) 679-9907 Ext. 1

Check out our latest ADU projects!


US Modular

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