ADU Permit

Ever since California has relaxed zoning regulations to combat the shortage of affordable housing in the state, an increased number of homeowners in the state are maximizing and optimizing their existing living spaces, and now it is your turn. Building an ADU, however, can be a comprehensive and complex endeavor. No matter what type of additional unit you have envisioned, you will need to obtain a permit for it from the local department of building and safety before breaking ground.

The process of obtaining a permit, however, can be perplexing, frustrating, and exhausting for many homeowners. Therefore, it is advisable to seek the stewardship of an ADU expert who can guide you through the process.

Los Angeles Permit Expediting Experts

We, at Construction Consulting Services specialize in handling plans and permits approvals for all types of ADUs in the greater Los Angeles area. Being an uncontested design-build firm in town, we stay on top of the state’s latest ADU laws and codes and know exactly what it takes to get an ADU permit processed, approved right on time, and within budget.

From sketching out the floor plans to drafting construction documents and application submission to any plan reviews, we work breathlessly with our clients until a permit for their ADU is issued.

CCS Inc Is a One Stop Permitting And Can Help You With Any Permit Need Including:

ADU Permit in Los Angeles

The 2020 California State Laws for building an ADU in Los Angeles are as follows: 

Attached ADUs

An Attached ADUs must comply with the following requirements


Lot size

There is no minimum lot size requirement for building an attached ADU.

Utility Connections

An attached unit may be connected to the main house utilities and drainage.

Separate Entrance

An ADU unit that is attached to the primary dwelling will need its own separate entrance.

Height Limit

The height of an attached ADU must match the height of the primary dwelling.


An attached secondary dwelling must have a side retain and rear setback of at least four feet. No setbacks are required if the new unit is carried out through the conversion of an existing space.

Parking Requirements

There is no parking required if the attached ADU is located near public transit or if the expansion is carried out through the conversion of an existing space.

ADU Size

The floor area of an attached dwelling unit should not be more than 50 percent of the primary house it is attached too.

Detached ADU

A Detached ADU must comply with the following requirements



A detached ADU must have a minimum floor area of 150 sqft and can be up to 1,200 sqft in a single-family zoned lot

Utility Connections

Secondary dwellings that are separate from the primary house must have separate utility connections like electrical, plumbing, and sewage.

Separate Entrance

ADUs that are separate from the primary structure are required to have their independent entrance.

Height Limit

The height of a single-story unit separate from the main structure can be up to 16 feet. A two-story ADU can have a maximum height limit of 25 feet.


A detached secondary dwelling must have a minimum side and rear setbacks of four feet. No setbacks are required if the new unit is carried out through the conversion of an existing space.

Parking Requirements

There is no parking required if a detached ADU is located near public transit or the new dwelling is created through the conversion of an existing space. Local municipalities may require uncovered parking if public transit is not available. 

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Additional Requirements to Homologate an ADU in Los Angeles

Both attached and detached units must also comply with the following accessory unit rules and regulations.


Bedrooms/ Living Spaces

An ADU may feature up to two bedrooms/ living spaces, with a minimum lot size of 70 sqft and a maximum of 400 sqft.


An ADU must have at least one of three bathrooms allowed with a minimum size of 30 sqft.


An ADU must also have a kitchen with a minimum size of 50 sqft.

Legalize My Unpermitted ADU

If your ADU was built without the required inspection and permits, it is advisable to apply for its reprieve and legalization to make sure to eliminate worries about a code enforcement action against you. At CCS, we provide end-to-end assistance to our clients to streamline the process of obtaining a post construction ADU permit. Whether you want to legalize your illegal ADU in a duplex or ADU in a triplex, we will work with you to find the best way possible to get it up to the code.

ADU Amnesty Program

Fortunately, the state of California offers an amnesty program to endorse the legalization of qualifying unpermitted secondary dwellings.

  • The ADU was constructed or converted before December 31, 2019.
  • An occupant currently lives in the ADU
  • There is no permit application currently in progress to legalize your unpermitted unit

Our Process to Design & Permit Your ADU

Here is how we help you in designing a floor plan and permit your ADU.

Site Visit

We begin the process with a complimentary visit to your house. During this phase, we will determine whether your lot is eligible to have an ADU in accordance with the latest building rules and regulations.  If it does, we will sit with you to understand your needs and features you desire in your new dwelling and discuss other factors like constructability, cost estimates, and the construction timeline of your project.


During this process, we will explore various ADU design ideas and take into account all the relevant factors to draft a plan for your new unit.

Construction Documentation

Once the design is approved by you, we will begin the drafting of construction documents. During the process, our engineers will design a structural system for your ADU to describe exactly how it will be built. 

City Permitting

Upon your approval, we will submit the complete set of construction documentation to the Los Angeles Department of Building and Safety for a permit. We will also remain available for any post-submission follow ups on any questions or plan reviews from the building authorities.

Use our estimates form to send us the most important details about your ADU project and get for free the estimated costs for your ADU.

Frequently Asked Questions

How Much Does It Cost to Ratify an Illegal ADU in Los Angeles?

The cost of legalizing an ADU in Los Angeles depends largely on its type and the extent of work needed to be done. We highly recommend you to obtain quotes for the process from an experienced ADU contractor like us.

How Much Does an ADU Design and Permit Cost in Los Angeles?

Depending on the size and complexity of the project, the cost to design and obtain the permit for your ADU can be anywhere from $1,200 and $11,000.

How Long Does It Take to Approve an ADU License in Los Angeles?

The process of issuance of an ADU permit usually requires two to four months.


Let Us Navigate the Process of Permitting Your ADU

Whether you want to obtain a permit for your new ADU construction or legalize your existing unpermitted dwelling, let CCS Inc navigate the process for you. Our journey with our clients does not end with the issuance of a permit. We will build your ADU from the ground up exactly the way you have visualized and will be available to assist you through post-construction inspections until you obtain a certificate of occupancy. Call us at (323) 405-8909 to learn more about the process of obtaining an ADU or schedule an appointment with our experts


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