Most homeowners choose to work with some type of design professional to plan their ADU and help throughout the process. Bringing on a professional early in the process is often key to getting your ADU approved quickly, managed efficiently, and built cost-effectively. Relevant experience and fit will be critical.

There are a variety of types of designer, and they may be an architect, builder, “designer,” design/build, or a modular/prefab company. If you’re hiring a local individual or team, they’ll likely start the process by visiting your home and talking to you about your ideas and goals. If it seems like a good match, they will prepare a proposal detailing their services and fee. Professionals typically charge for an initial consultation or proposal.

Note that if you’re not using a licensed architect to design your ADU, your plans may need to be stamped by a licensed engineer. Check with local staff early on.

See our Exercises for a list of questions to ask a potential architect or designer, our Glossary to be clear on terms, and our Guidebook for more details.

Once you have a design established with your architect/designer, it’s a great idea to discuss it with local staff so they can point out any issues before you prepare your application.

Depending on the location, you may be able to schedule an appointment or you may be able to visit the Planning Counter or Permit Center. For contact information, see the Local ADU Rules.

This is also a good time to reach out to utility agencies (water, sewer, gas, etc.) to inquire about their infrastructural requirements and confirm connection and service fees.

Some locations may have pre-approved plans that applicants can customize for their properties. Currently Oakland and Fremont have pre-approved plans and more locations may be adding programs. Check Local ADU Rules to see if your location offers pre-approved or pre-reviewed plans.