Accessory Dwelling Units (ADU) and Junior ADUs (JADU)

What is an accessory dwelling unit?

An Accessory Dwelling Unit (aka, “second unit,” “in-law unit,” or “granny unit”) is an additional dwelling located on the same lot as a single-family or multi-family development, An Accessory Dwelling Unit may be attached to the primary residence, detached from the primary residence, or contained within an existing residence or accessory structure. A Junior Accessory Dwelling Unit (JADU) is a unit in an owner-occupied residence that is no more than 500 square feet and contained entirely within the single-family structure.

What is the Review Process?

In order to make the review process as efficient as possible, Accessory Dwelling Unit (ADU) and Junior Accessory Dwelling Units (JADU) applications are submitted to the Building Division as a building permit. See the Permit Process Page for Small Project and Large Project processing. The Planning Division will review the Building Permit application.

What Regulations Apply to Accessory Dwelling Units?

The City follows State ADU law. See the updated ADU Handbook. Local ADU regulations are found in Chapter 18.23.

ADU Marin

See ADU Marin for information on each step of the process, from thinking about building to permits and construction. It features stories from homeowners who have built an ADU and renters now living and working in Marin, along with more than a dozen floorplans. Plus, there is a calculator to estimate what it might cost and potential rental income. The workbook goes deeper into the process and is full of exercises, checklists, and activities. Whether a homeowner needs to brainstorm ideas, choose a contractor, find a tenant to rent their finished ADU, they will find helpful guidance and resources each step of the way.