County of Marin - News Releases - Accessory Dwelling Units

For Immediate Release
May 26, 2021

Effort to Spark More Accessory Dwelling Units

Fee waivers in Marin designed to encourage construction, alleviate housing crisis

San Rafael, CA – The County of Marin remains eager 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). Financial breaks to encourage construction started in 2017 and received a new endorsement May 25 from the Marin County Board of Supervisors.

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 home’s accessory dwelling unit in Marin County is where a garage used to be.

Considering the booming price of housing in Marin (up 17.9% between April 2020 and April 2021 despite the COVID-19 pandemic), the Supervisors are keen to address the severe housing shortage for lower-income residents in one of the country’s most expensive regions in which to live. The North Bay wildfires over the past four years, concerns about homelessness, and the need by many seniors on fixed incomes to earn additional monthly funds by renting out rooms have increased a focus on affordable housing. With those factors in mind, breaks on building and permit fees for new separate rental units inside and adjacent to existing homes have been extended and expanded through December 31, 2023, with Board approval.

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.

The permitting program for such dwelling units is overseen by the Marin County Community Development Agency (CDA). Starting June 14, residents who rely on septic systems are eligible for grants to construct ADUs as part of a pilot program, with priority given to those who will rent their ADUs affordably. Also, property owners considering ADUs and junior ADUs (aka JADUs) should consult with the County Assessor’s Office to determine if the type and extent of improvements will increase their property tax assessments.

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.

In 2020, the County gave 36 fee waivers for the creation of ADUs/JADUs, totaling $71,000. That was an increase from the previous year when the County gave 20 fee waivers worth $49,000.

The overall number of permits given to second units has increased significantly since the initial passage of the fee waiver program. In 2017, the County permitted seven second units, 10 in 2018, 67 in 2019, and 50 in 2020. The increase was attributed to an educational campaign called ADUMarin, which simplified materials about accessory units and resulted in greater countywide collaborations. 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, too. The increase in second units in Marin is also attributed to major statewide incentives and legislation, first introduced in 2019 and expanded upon in 2020.

CDA Planning Manager Leelee Thomas said the pandemic and a corresponding moratorium on non-essential construction hampered ADU and JADU creation in 2020. With the construction business rebounding this spring, Thomas said it’s time to remind property owners that ADUs and JADUs provide opportunities for people to move to or stay in Marin and increase the odds of a homeowner remaining in their home instead of being displaced.

“With these incentives, we hope to stimulate development of affordable ADUs and JADUs,” Thomas said.

The best source about ADUs and JADUs in Marin is the ADUMarin website. 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.


Aline Tanielian
Planner, Housing & Federal Grants Division
Community Development Agency

3501 Civic Center Drive
Suite 303
San Rafael, CA 94903
(415) 473-3547
Email: Aline Tanielian