Los Angeles Accessory Dwelling Unit (ADU) Regulations

Los Angeles Accessory Dwelling Unit Regulations

If you are planning to build an Accessory Dwelling Unit (ADU) in Los Angeles, you need to know the exact regulations that are enforced by the city zoning department.  The law relating the ADUs is governed by the regulations passed by the State of California and it completely nullifies and overrides regulations enforced by the City of L.A. 

The local bodies can pass ordinances complying with State law for granny flats or can adopt the State law as it is.  Here, let us see the latest legal provisions that have say in building the granny flat you want to build. Los Angeles has not passed a separate ordinance governing the Accessory Dwelling Units and is operating under the State law.

An ADU is a way of adding value to your existing home and this must be planned and built as per the following regulations:

  • An ADU can be built only on R-A, R-1, R-2, R-3, R-4, A-1 or A-2 (or any other zone that allows single-family residences by right)


  • It must be designed in such a way that it has its own entrance, and this must be completely different from the entrance to the main house. It must also have a living space, bathroom and a kitchen.


  • As the granny flats are independent in existence they can be rented, throughout the year and they can be added to the house as a way of adding more value to the main property.


  • The Accessory Dwelling Units can be built as garage conversions, standalone structure, an alteration to an existing basement structure or an attic, or a separate structure that is attached to the main building.


  • No lot size is prescribed as eligible to build a granny flat.


  • Regarding the size of the proposed ADU, an attached ADU cannot exceed 50% of the area of the primary house property.


  • If the ADU is a detached structure from the primary house property it can have an area up to 1,200 sq. feet regardless of the area of the main home.

  • Though the height of the ADU is not specified it must comply with your local building code.


  • In case the Accessory Dwelling Unit is built through garage conversion, a separate parking space is needed and it can be anywhere on the property, in driveway or in tandem also.


  • As compact parking is not allowed it is necessary that the parking space is at least 8.5 feet by 18 feet size.


  • In case the property is situated within half a mile of a public transit then you need not provide for a parking space.


  • Likewise no parking space is needed in case you live in historic district.


  • No parking space to be provided for the Accessory Dwelling Unit that is built by altering part of the primary property like a basement or an attic.


  • No parking space is insisted if you are living within one block of a car share.


  • All ADUs have to comply with the setback rule of 5 feet on the side and the rear of the property. But set back is not necessary if you are converting an existing part of the primary house property or if you are converting an existing structure.


  • There is no clause as to the owner occupancy and hence both the primary house and the Granny Flat can be rented separately.


  • The state law permits the long term lease of the ADU but your local government can decide if the Granny Flats can be let on short- term lease also.


  •  If you want to sell the accessory Dwelling Unit it cannot be sold independent of the primary house and it must be sold along with it as a single unit.


  • Installation of fire sprinklers are not needed in an Accessory Dwelling Unit if the primary housing property is not required having fire sprinklers.

How to evaluate your Building costs of the Granny Flat:

Homeowners usually miscalculate the cost of building their Accessory Dwelling Unit. They usually fail to take into consideration the fixed costs and the expensive square footage including the costs involved in building the kitchen and the bathroom. Due to this when you want to add an ADU with the intention to keep it for some time, then adding a Granny flat is one of the best ways to maximize the value of your property.

An ADU when planned and built at the right price level instantly boosts the equity of your home and you are getting the benefit of earning an income by renting the new ADU or using the same for your family.