What permits do I need for an ADU?
Now that you know you’re allowed to build and have set a budget, here’s everything you can expect once you begin building your ADU.
Step 1: Submit Application
Your design team or ADU specialist will handle this step. We strongly recommend homeowners work with a professional throughout the planning and permitting process, or through the entire process.
The submittal and review process is often quite complex and can require significant architecture and building technology knowledge to go smoothly. Generally, it is better to have a professional on your side to explain the requirements and the choices you must make.
To apply for permits, you and your project team will need to complete the forms required by your jurisdiction, provide detailed drawings and other documentation, and pay permitting fees. The City will provide comments on your application that you will need to address and re-submit for approval.
Once your application is deemed complete—meaning you correctly submitted all of the required materials at the required level of detail—the various reviewing departments and agencies will begin their review.
Applications vary by city, but the following is a checklist of typical application components:
Structural plans
foundation plan, framing plans, and associated detailsSite plan
depicting existing and proposed structures
Building/architectural plans
floor plans, elevation plans, and details
Other items
Title 24 energy calculations, best management practices for erosion control, photos, etc.
Step 2: Revise Application
The city will provide comments on your application. They have up to 60 days to do so, but it can take longer currently because of the pandemic.
Your team will then respond to any comments, adjust your project to meet the standards and regulations, and re-submit the application. Depending on the completeness of the submittal, most projects require one to three rounds of revisions working with city staff.
Step 3: Receive Permits
Before receiving the final permits, homeowners will have to pay all required fees, including fees required by other agencies.
Once your application is approved and all fees are paid, you will be issued permits to start construction.
The number and types of permits needed for an ADU varies by community, but all will require a building permit. Additional permits, as well as utility connections, may be needed depending on your property.
About Casita Coalition
Casita Coalition is the only statewide, multi-sector organization that brings together all key players to remove policy barriers, making a big impact through small homes. Working through our Board, Advisory Committee, and Working Groups, we draw on the diversity of expertise and experience of our members to make it easier to build small homes in all neighborhoods across California. Visit www.casitacoalition.org to learn more.