County of Marin - News Releases - Accessory Dwelling Units

For Immediate Release
January 14, 2020

More Enticements for Accessory Dwelling Units

Financial breaks designed to spark construction, alleviate housing crisis

San Rafael, CA – New financial breaks to encourage property owners in unincorporated Marin County to create affordable rental housing units on their existing property, known as second units or accessory dwelling units (ADUs).

The front of home in San Rafael is shown with the main front door on the left and the accessory unit front door on the right.This San Rafael home has its main front door on the left and the door to its accessory unit (ADU) on the right.

On January 14, breaks on building and permit fees for new separate rental units inside and adjacent to existing homes were extended and expanded by the Marin County Board of Supervisors. The Board has been working to address a severe housing shortage for lower-income residents in one of the country’s most expensive regions in which to live.

As an incentive, those renting out their ADUs will have permit fees waived up to $10,000 if they rent to tenants with household incomes below 80% of the local median. There’s a $5,000 break on permits for ADUs that are rented between 80-120% of the median income. The financial incentives are extended to cover fines or fees for property owners rehabilitating existing units or legalizing unpermitted ones. Property owners considering ADUs and junior ADUs – or JADUs – should consult with the County Assessor’s Office to determine if the type and extent of improvements will increase their property tax assessments.

Property owners planning to create new units could save up to $2,500 for qualified ADU projects rented above 120% of the area median income, and $1,500 for new JADU construction. The waivers would cover a significant proportion of permit costs, which averaged $8,600 in 2019. In addition, road impact fees would be waived for the owners of qualified projects.

The main difference between an ADU and a JADU is that ADUs have a more complete independent living setup with a full kitchen and bathroom. JADUs are converted from an existing bedroom and have smaller food preparation area, sometimes share bathrooms. Both types of units have entrances/exits separate from the property’s main entrance/exits, and both are seen as a way to increase options for renters and support homeownership for low and moderate income homeowners.

The new local rules are retroactive to January 1, 2020 and are valid through December 31, 2020. The program is overseen by the Marin County Community Development Agency (CDA).

The financial break comes after the passage of state legislation that requires local agencies to reduce regulatory constraints on such housing construction. But this is not the first such enticement for accessory development. The first proposed fee waiver for ADUs and JADUs in Marin was adopted by the Board in 2017 in response to sudden population displacement related to the North Bay wildfires. In December 2018, the County extended and expanded the 2017 fee waiver program.

The cost of housing in Marin, considered a crisis by the Board, is regularly displacing people who have been priced out and preventing people who have jobs in Marin from living close to their workplaces. Thousands of people grew up or work in Marin have been unable to find local housing that fits into their budget, prompting permanent relocation or long commutes.

“ADUs and JADUs are beneficial in two ways: they provide opportunities for people to move to or stay in Marin, and they increase the odds of a homeowner remaining in their home instead of being displaced,” said CDA Planning Manager Leelee Thomas. “We hope the Board’s action results in a stimulation of development of affordable ADUs and JADUs. It’s more socially and environmentally sustainable for Marin to be home to residents from a wide variety of income levels.”

Marin CDA staff has worked with Marin’s Aging Action Initiative and Marin County Commission on Aging on public education about the additional units the past several years.

The best source about ADUs and JADUs in Marin is Also, anyone may subscribe to receive e-mailed notifications from CDA about housing-related issues. For more information on the applicable standards and permit process for JADUs and ADUs, contact the Marin County Building and Safety office at 415-473-6550 or check the Building and Safety Code Division webpage.


Jillian Nameth Zeiger
Housing and Federal Grants Planner
Community Development Agency

3501 Civic Center Drive
Suite 308
San Rafael, CA 94903
(415) 473-7549
Email: Jillian Nameth Zeiger
CDA website