Accessory Dwelling Units

Community Development Agency

Accessory Dwelling Unit Incentives

Updates and Announcements

 SB2 ADU Septic Pilot Program

The SB2 ADU Septic Pilot Program is geared towards homeowners in unincorporated Marin who are interested in building a second unit (also known as an Accessory Dwelling unit, or ADU) and currently have a Class I or Class II septic system installed on their property.

Wastewater engineer consultants will design upgrades to the selected septic systems to allow homeowners to build the proposed ADU on site. This program does not include funding for the construction of the upgrade or the construction of the ADU. ADUs designated as affordable housing (any unit rented at or under 120% of Area Median Income) will be given preference in the selection process. The application has been extended to Friday September 10, 2021. Please direct all questions about the program to AffordableHousing@MarinCounty.org or (415) 473-7309.

ADU Septic Pilot Program Application

Alternatively, a PDF version of this application is available, and may be filled out and submitted either electronically by email, or by mail to: Attn Housing and Federal Grants, 3501 Civic Center Drive Suite 308, San Rafael, CA 94903. Hard copies are available upon request. 

 ADU Fee Waiver Program

Under the program, in exchange for a property owner’s agreement to rent their unit at affordable levels, County permit fees for ADUs may be waived up to the following: 1) Up to $10,000 for ADUs that are rented at rates at or below 80% the Area Median Income, 2) Up to $5,000 for ADUs that are rented at rates between 81-120% of the Area Median income, and 3) Up to $2,500 for ADUs that are rented at market-rate.

The fees waived may include: Community Development Agency fees such as planning, building and safety, and environmental health services, and Department of Public Works fees such as traffic mitigation. Applications are accepted on a rolling basis. More information is available in the collapsible panel below.

ADU Fee Waiver Program Packet (includes application)

An Accessory Dwelling Unit (ADU), also known as an in-law unit, second unit, or cottage, is an additional residential dwelling unit on a single-family or multi-family residentially zoned property. An ADU can be an attached or detached dwelling unit, providing independent living facilities for one or more persons that has a full, separate kitchen (including stove, refrigerator, and sink), separate bathroom and separate entrance.

A Junior Accessory Dwelling Unit (JADU) is an additional, independent living unit generally created through the conversion of an existing bedroom in a single-family residentially zoned residence, and also has a separate entrance. A JADU does not need to have all the same features as an ADU, such as a separate bathroom. However, per the Marin County Development Code 22.130.030, the unit should have a wet bar (but not a full kitchen) and must be certified as a JADU by the Community Development Agency Director.

To learn more about how to build and rent out a second unit in Marin County, visit ADU Marin. ADU Marin is a collaborative effort across Marin cities and towns to offer resources and educational materials to facilitate building, permitting and renting out second units.  

Example floor plans of second units. More found at adumarin.org

Example ADU and JADU floor plans. Additional floor plans are located under "Get Inspired" on the ADU Marin website.

 

ADU and JADU Fee Waiver Program

On May 25, 2021, the Board of Supervisors approved an extension to the Accessory Dwelling Unit (ADU) Fee Waiver Program, which offers property owners fee waivers for the development of second units in unincorporated Marin County. This program offers a tiered fee waiver structure to support the development of additional affordable rental housing stock, by further incentivizing the development of second units that are rented to low- and moderate-income households. The Resolution is in place through December 31, 2023.

Under the program, in exchange for a property owner’s agreement to rent their unit at affordable levels, County permit fees for ADUs may be waived up to the following:

  • Up to $10,000 for ADUs that are rented at rates at or below 80% the Area Median Income,
  • Up to $5,000 for ADUs that are rented at rates between 81-120% of the Area Median income,
  • Up to $2,500 for ADUs that are rented at market-rate.

The fees waived may include: Community Development Agency fees such as planning, building and safety, and environmental health services, and Department of Public Works fees such as traffic mitigation.

Review the ADU Affordability Program packet and accompanying Frequently Asked Questions document for more information and details. To be considered for fee waivers, owners should submit the attached Fee Waiver Application in the ADU Affordability Program packet.

ADU Fee Waiver Program PacketFrequently Asked Questions (FAQs)

Please contact the Housing & Federal Grants Division with any outstanding questions at (415) 473-7309, or by email.

Fee Waiver Program History

2021

On May 25, 2021, the Board of Supervisors approved an extension to the Accessory Dwelling Unit (ADU) Fee Waiver Program, which offers property owners fee waivers for the development of second units in unincorporated Marin County. This program offers a tiered fee waiver structure to support the development of additional affordable rental housing stock, by further incentivizing the development of second units that are rented to low- and moderate-income households. This program, in place through December 31, 2023, includes a waiver of up to $2,500 for eligible ADUs rented at or above market rate, up to $5,000 in fees for an ADU that is rented at moderate-income rates (between 81-120% of Area Median Income guidelines), and up to $10,000 in fees for an ADU that is rented at low-income rates (up to 80% of Area Median Income guidelines). These fees may include: Community Development Agency fees such as planning, building and safety, and environmental health services, and Department of Public Works fees such as traffic mitigation.

Board Packet | Resolution 2021-34 

2020

In January 2020, the Board of Supervisors approved an expansion of ADU and JADU fee waivers that responds to the affordable housing crisis in Marin County by further incentivizing the development of ADUs that are rented to low- and moderate-income households. This program, which expired December 31, 2020, includes a waiver of up to $2,500 for eligible ADUs rented at or above market rate (In 2019, eligible ADUs received a $3,500 fee waiver under 2018-135), up to $5,000 in fees for an ADU that is rented at moderate-income rates (between 81-120% of Area Median Income guidelines), and up to $10,000 in fees for an ADU that is rented at low-income rates (up to 80% of Area Median Income guidelines). These fees may include: Community Development Agency fees such as planning, building and safety, and environmental health services, and Department of Public Works fees such as traffic mitigation.

Board Packet | Resolution 2020-05

2019

In October 2019, the Governor signed amendments to the State Government Code Section 65852.2 (AB 881, SB 13, AB68) and related legislation that require local agencies to reduce regulatory constraints, including limits on the development fees that local agencies can charge for ADUs. The Department of Public Works Traffic Mitigation Fee will no longer be charged for ADUs that are 750 square feet or less, pursuant to AB 881. Additionally, the Governor signed amendments to State Government Code Section 65583 (AB 671 and AB 139). These bills require Housing Elements to promote ADUs for affordable housing. 

2018

On May 22, 2018, the Board of Supervisors approved amendments to the original authorizing resolution (Marin County Resolution No. 2018-47). Those amendments included a clarification of the period during which a participating property owner would agree to refrain from using the unit as a short-term rental, and it required any violating property owner to refund the County.

On December 18, 2018, the Board of Supervisors approved amendments to the original authorizing resolution include changes made from 2018-2019 (Marin County Resolution No. 2018-135), that added a fee reduction of up to $3,500 for eligible ADUs and waived Roadway Impact Fees associated with the creation of eligible JADUs in addition to the existing fee reduction cap for JADUs of $1,500.

Board Packet (12/18/2018) | Resolution 2018-135

Board Packet (05/22/2018) | Resolution 2918-47

2017

In October 2017, the North Bay Wildfires destroyed thousands of homes in the neighboring counties of Sonoma and Napa, displacing residents and thereby exacerbating Marin’s preexisting affordable housing crisis, caused in large part by a shortage of available housing.

In response, the Board of Supervisors acted in December 2017 to authorize the Community Development Director to waive or reduce building permit fees for JADUs as a financial incentive aimed to galvanize property owners into creating supplemental rental housing within the footprint of existing developed residential properties (Marin County Resolution No. 2017-132). This fee waiver policy was developed to augment a state initiative to promote creation of ADUs and JADUs by easing the regulatory requirements for creating these types of units. Additionally, to encourage use of JADUs as permanent rental housing, the Board of Supervisors included a provision requiring that JADUs may not be used as a short-term rental for one year following issuance of the fee waiver to qualify for the fee waiver program.

As the Building and Safety Division operates under a full cost recovery policy through the collection of user fees, the Board of Supervisors agreed to allocate $25,000 to backfill the loss of fee revenue for JADU building permit waivers. Additionally, to maximize the number of projects that would benefit from a fee waiver incentive program, while also retaining a fee waiver amount that would act as an effective financial incentive for the waiver, the Board of Supervisors also supported a proposal to cap individual building permit fee reductions to $1,500 per eligible JADU.

Board Packet | Resolution 2017-132 

Resources