ADU Resources

ADU Marin Website

For general information regarding ADUs, residents can visit ADU Marin, an interactive  website developed through a partnership of the County of Marin, other Marin County agencies, and the ADU Center.  ADU Marin provides examples of different types of ADUs, template floor plans, potential costs and benefits, the general process for building an ADU, and guidance for persons interested in renting out an ADU. The webpage even provides a calculator to help estimate the costs of designing and building an ADU. 

HCD Webpage and ADU Handbook

Another source of ADU-related information California Department of Housing and Community Development (HCD) Accessory Dwelling Unit webpage, which provides information on funding opportunities for homeowner’s and an ADU Handbook.  The ADU Handbook was updated in January 2025 and provide extensive FAQs (Frequently Asked Questions) on ADU regulations and development and also provides information on the State Laws adopted to-date to facilitate ADU development in California. The ADU Handbook and other resources for ADU development can be found on HCD's webpage here: https://www.hcd.ca.gov/policy-and-research/accessory-dwelling-units.