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.
Here are a few of the most frequently asked questions about permitting. See the content below and our ADU Guidebook for more guidance, resources, and tips for all steps of the process.
Submitting an application is different in each location. Some have online portals while others ask for multiple sets of paper copies on various sizes of paper. Some locations require one application package, while otherwise require separate processes from the Planning and Building departments. Check with local staff to confirm the application process and requirements and for details about permit materials. See more about the permit process below and in our Guidebook .
Some locations may require homeowners to upsize service and or meters to meet capacity requirements. Check with local staff to learn more about local requirements for utilities.
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.
These guides and resources are here for you as you get familiar with the process of building your dream ADU.
A summary of the ADU rules where you live.
A step-by-step guide to building an ADU in Alameda County.
Taking your design through the permitting process may seem overwhelming, but with thorough preparation and an understanding of what to expect, it can be straight-forward. Permitting starts with an application package and ends with a building permit, which signals your ability to start construction.
Before you begin …
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 local staff (Local ADU Rules) to schedule a meeting and check out our Exercises for help planning the meeting.
Once your ADU plans are finalized, you and your designer or contractor will submit your application package for approval. Your team will lead the process to prepare an application package.
Application requirements vary by location, but applications typically include:
Some locations have an ADU permit application or submittal requirements checklist that outlines all the required documentation and materials that must be submitted. Contact local staff to learn about your location’s application process and requirements.
Submitting an application is different in each location. Some 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. Check Local ADU Rules for more details.
After your application is submitted, the first step will be for local staff 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.
Local staff will complete their review and provide any comments within 60 days, although it’s usually faster. Most likely, this review will happen by staff (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 locations allow you to check your permit status online.
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.
ADUs can be charged a variety of fees from your City or County, the State, and other agencies. Some fees are based on the details of the project while others are fixed. Surprisingly, local governments do not control many of the most expensive fees, like school and water fees, which are assessed by other agencies and dependent on the size or location of your ADU. The fees listed below are often required, but see our Guidebook and/or contact us for more information.
Fees may include:
The total amount of fees depends on your property and plans. The Alameda County ADU Calculator can provide an estimate of fees for your project.
Learn more about the ADU Rules
