Phase Five
Permitting
- Understand what's required in your permit application
- Know what to expect from application review
- Get started on your application
- Understand the types of fees you may need to pay
Project timeline
The Permitting phase typically takes 1-6 months. Most ADU projects take 12-18 months to complete, but some extend to 24 months or more.
Step-by-Step
Prepare your application package
Permitting Step 1
Once your ADU plans are finalized, you and your designer or contractor will submit your application package for approval.
Your designer or contractor will submit your application package to your local Planning Department for approval. Your team will lead the process to prepare an application package.
Application requirements vary by where you live, but applications typically include:
- Site plan (depicting existing and proposed structures)
- Building/architectural plans (floor plans, elevation plans, and details)
- Structural plans (foundation plan, framing plans, and associated details)
- Other items (Title 24 energy calculations, deed restriction, address assignment form, or other materials required by your location)
- Deed Restriction filed with the County
- Supplementary Materials
Some local Planning Departments have an ADU permit application or submittal requirements checklist that outlines all the required documentation and materials that must be submitted. Contact local staff or the ADU Resource Center to learn about your specific application process and requirements.
Submit your application
Permitting Step 2
Submitting an application is different depending on where you live. Some local Planning and Building Departments have online portals, and others ask that multiple sets of paper copies be submitted in-person. Some fees may be due when submitting your application, and some may be due later. Contact local staff for more details.
After your application is submitted, the first step will be for your local Planning Department to review it for completeness. They will confirm your application is complete (meaning you correctly submitted all required materials and details) and then other departments and agencies will begin their review.
ADUs within the Coastal Zone may require a hearing with the California Coastal Commission. Use the San Mateo County Coastal Zone Boundary map to check if you’re in the coastal zone and talk to local staff to see if this applies to your project.
If you are building a conversion ADU or any ADU within an existing structure, local inspectors may be required to conduct a walkthrough of the intended space as a part of the application process. You will be notified by local staff if you need to schedule this inspection.
Meeting with locAL STAFF
It’s helpful to meet with local staff before submitting your application. While not required, meeting with your designer and local staff before you submit your application might save time later in the process. Contact Planning staff to schedule a meeting and check out our Exercises for help planning the meeting.
Revise your application
Permitting Step 3
Your local Planning Department will complete their review and provide any comments within 10-20 days. If the Planning Department requires any modifications to your plan, your team will revise and resubmit the application.
Local staff will complete their review and provide any comments within 60 days, although the process is often quicker. Most likely, this review will happen at a staff level (no hearings), but in less common instances, an additional permit or public hearing may be required.
If modifications to your plan are required, your team will revise and resubmit the application. Under state law, agencies/departments reviewing your plans must provide a full set of comments with a list of incorrect items and how those can be fixed. Many local Planning Departments allow you to check your permit status online.
Receive permits
Permitting Step 4
After your application is approved, staff will let you know that your permit is ready and how you can receive it. Once you have paid any remaining fees and you have your permit, you can begin construction. Often permits must be displayed at the site. They are usually valid for 180 days and often renew automatically as long as construction is ongoing and inspections are occurring.
Frequently Asked Questions
Here are a few of the most frequently asked questions about permitting. See the content above for more guidance, resources, and tips for all steps of the process.
What permits are required for ADUs and JADUs?
Application requirements vary by where you live, but applications typically include:
- Site plan (depicting existing and proposed structures)
- Building/architectural plans (floor plans, elevation plans, and details)
- Structural plans (foundation plan, framing plans, and associated details)
- Other items (Title 24 energy calculations, deed restriction, address assignment form, or other materials required by your location)
- Deed Restriction filed with the County
- Supplementary materials
Some local Planning Departments have an ADU permit application or submittal requirements checklist that outlines all the required documentation and materials that must be submitted. Contact local staff (Link) to learn about your specific application process and requirements.
How much does it cost to get permits for an ADU?
ADUs can be charged a variety of fees from your local government, the State, and other agencies. Some fees are based on details of the project while others are fixed. The total amount depends highly on your property and plans, but local staff can most likely provide an estimate once you have a good idea of your project details. See the Budgeting and Finance page for more details.
Are there water and sewer issues I should consider?
You may be required to upsize service and or meters to meet capacity requirements. Check with local staff to learn more about local requirements for utilities.
Can my ADU be stopped because of other noncompliance issues on my property?
In most cases, state law no longer allows cities and counties to comment on pre-existing zoning issues unrelated to the ADU. For example, you should not receive comments about correcting the main house or a fence unrelated to the ADU, unless there is an obvious public safety issue.
Learn more about permitting
Know what to expect when you start your application
