Like any construction project, permits are an essential part of the process for building an accessory dwelling unit (ADU) on your property to make sure that it complies with the local zoning, building, and construction codes.
Whether you want to convert a part of your garage, build an addition to your existing house, or create a backyard ADU, it is important to determine what a permit for your proposed ADU will cost you when performing your due diligence before you move ahead with the project.
The cost of the ADU permit varies from project to project. There are a number of variables that impact the cost of a permit, including:
- The type of permit you need
- The estimated value of the construction being carried out
- Number of square feet your project added to the property.
- Additional permits required for your project.
- Inspection fees
The total cost of an ADU permit is calculated by the cumulative costs of architectural and structural plan designs, zoning permit fees, building permit fees, impact fees, and other miscellaneous fees and development taxes.
On average, the cost to design and permit an ADU in Los Angeles can range from as low as $6,000 to above $20,000.
Generally, the homeowners aspiring to build an ADU have to pay a plan check fee (before the plan is checked) and a final permit (when it is set to be issued) to the Los Angeles Department of Building and Safety (LADBS). The plan check fee usually costs between $1,300 to $5,000. while the final permit may range from $1,000 to $10,000.
Here’s a breakdown of average ADU permit costs in Los Angeles.
ADU Design Costs in Los Angeles
You will need a complete set of professionally drawn plans of your proposed ADU to the LADBS to obtain a permit.
The design fees vary widely depending on the complexity and size of your project.
Full ADU plans cost between $6,000 and $15,000, depending on their size and complexity.
Typically, the homeowners are required to submit;
- Architectural and Structural plans
- Engineering Plans (for wall, roof, and ceiling framing)
- Title 24 Report (energy efficiency report)
- Electrical Plan

Estimated ADU Permit Fees and Costs in Los Angeles
Here are the average fees you are expected to pay for your ADU permit.
Zoning Permit Fees
The zoning permit fee for an ADU in Los Angeles range from as low as $30-$500 for normal and up to $4,000 for a complex approval. A separate zoning permit is sometimes not required, and its cost is added to the building permit fees.
Building Permit Fees
You will need a building permit if your ADU requires electrical, mechanical, and plumbing utilities besides the individual costs involved in designing plans for each of them.
Building permit fees depend largely on the number of square footage to be added. This fee can either be fixed or included in the zoning permit fee for the proposed dwelling.
On average, you are likely to spend somewhere between $450 to $2,500 for a low-end permit and between $4,500 and $15,000 for an average high-end building permit.
Impact Fees
If the size of your proposed ADU is between 500 to 750 sqft, you will most probably have to pay sewer and water connection fees and school impact fees.
Sewer and Water fees usually cost up to $2,500, while impact fees range from $3-$4 per square foot for a finished dwelling structure. If your ADU exceeds 750 sqft, traffic impact fees may also be imposed besides the abovementioned fees.
If your dwelling unit is less than 500 sqft, the building department can waive impact and some other fees.
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.
Certificate of Occupancy Cost
You need to obtain a certificate of occupancy before moving into your new dwelling. A city inspector will visit your property to sure that the electricity, plumbing, and HVAC system in your new unit are in optimal working order. Typically, a COO for an ADU costs between $300 to $600.
ADU Amnesty Program
In a bid to combat the statewide shortage of affordable housing in California, the state has announced an amnesty program to get illegal ADUs permitted by obtaining a retroactive building permit.
Your unpermitted ADU may qualify for the amnesty scheme if;
- It was created before December 31, 2019.
- An occupant currently lives in it
- There is no permit other application in progress to legalize it

Final Words
Since every ADU is unique and designed to the homeowner’s specific needs and aesthetic taste, it is tough to predict the exact permit costs in Los Angeles. Confusing costs, restrictive regulations, and lengthy permitting processes can make your ADU project a stressful and frustrating experience for you.
Therefore, it is important to have an experienced design-build firm on your side to manage the permits, zoning, and ordinances for you.
Permit Expediting Experts Los Angeles
For years, we at CCS Inc have been assisting homeowners just like you navigate the process of permitting their ADUs.
No matter in which way you want to create a secondary dwelling on your property, we can work with you at every step of the way to make the entire process simple and hassle-free for you.
Reach out to us today to know more about ADU permit costs in Los Angeles or schedule a consultation with our permit expediting experts.