Statewide Update: New California ADU Bills AB68, SB13, AB881, AB670 have passed. These laws create more options for building an ADU in 2020. Use ADU Services to learn how they affect your property!

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San Rafael ADUs

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PLANNING OFFICE The city has closed all operations during the COVID-19 outbreak. More information will be posted here once it becomes available. In the meantime, we are providing services for San Rafael properties based on recent projects and research.

The city government of San Rafael will approve ADUs under California's statewide mandated regulations.
The California Building Code (CBC) 2019 is adopted.
Relevant state bill updates for SB13, AB68, AB881, AB670 are shown in green below.

Last Updated 03/27/20


City Hint: The city permitted a total of 38 ADU project(s) in the past year of 2018, which makes it above average for ADU production compared to other cities statewide.


Number of ADUs allowed:

Under state law, each single-family home may now create at least one ADU. Owner occupied single-family lots may create one ADU and one Junior ADU. Multi-family lots, per every four existing residential units, may create one ADU, so long as the existing units were legally established.

As of January 1st, 2020

Types of ADUs allowed:

Detached ADU, Attached ADU, Junior ADU are allowed. Accessory Dwelling Unit (ADU)s may be new construction or converted from existing space. JADUs must be converted from existing space.

Lot size:

Accessory Dwelling Unit projects on single family or multi-family residential properties will not be subject to the minimum lot size of the underlying local zoning code or by special ordinance. ~ According To AB68

As of January 1st, 2020

ADU size:

Single-family and multi-family Parcels will be permitted to create up to 850 sqft for a one bed ADU or up to 1,000 sqft for a two bed ADU, regardless of the underlying zoning standards of the property. A JADU up to 500 sqft is permitted. The minimum size of any living unit (including Accessory Dwelling Units and JADUs) is 150 sqft according to Califronia Residential Code. ~ Updated: State Law AB-68

As of January 1st, 2020


Setbacks for a detached new construction Accessory Dwelling Unit (ADU) shall be no more than 4 ft from the rear and side lot lines. No setbacks shall be required for Accessory Dwelling Unit (ADU)s and Junior Accessort Dwelling Unit (JADU)s converted from legally eastablished existing space. Attached new construction Accessory Dwelling Unit (ADU)s and conversions from existing space to be expanded must comply with the setbacks of the underlying zone. ~ AB68 & AB881 Update

As of January 1st, 2020


Properties which convert an existing garage to an Accessory Dwelling Unit or Junior ADU will not be subject to replacement parking requirements. ~ Updated: State Law AB-68

As of January 1st, 2020

Fire Safety:

Per state requirements.

Shape, materials and style:

Review and approval of a discretionary Environmental and design review Permit by the Planning Commission pursuant to Chapter 14.25 will be required for any ADU proposed as follows:

An upper story addition to the main residence that exceeds 500sf
A detached ADU that is two-stories
A detached ADU located within side or rear yard setbacks required for the main structure setbacks
New construction on a lot subject to the Hillside Overlay (-H) District Development regulations; if required
for the addition per Chapter’s 14.12 and 14.25
Note: Upon application for review, the Community Development Directory may propose to downgrade review to the Zoning Administrator level, if a concurrent Use Permit is not required.

Architectural Compatibility

Prior to approval a City planner will review the design plans (and visit the project site in the case of legalizing a ADU) to ensure that the ADU incorporates the same or similar exterior colors, architectural detailing, roof pitch same or similar and exterior materials, and window style, as the structure containing the principal residence.


If the unit is added to a principal single-family dwelling, the height limit is 30 feet above grade. If a unit is proposed as an accessory structure, the height limit is 15 feet. (I.e., consistent with the underlying zoning district standards for height limits and measurement). Note that Use Permit and/or Design Review permits may be required for second units in accessory structures that exceed the height limit.

Design review:

ADUs are subject to ministerial review by the Planning Division prior to issuance of a building permit. Additional zoning entitlements may be required, as specified in San Rafael Municipal Code Section 14.16.285. A ADU review fee ($_____) and application form along with project plans (___ sets) must be submitted to the Planning Division which will verify whether the unit complies with the ADU Performance Standards. If building permit clearance is granted, a ADU deed restriction must be recorded for the property.
Review and approval of a discretionary Use Permit by the Planning Commission is required for any ADU proposed as follows:

A detached ADU that exceeds the foot height limit and/or located within side or rear yard setbacks required for the main structure
A ADU that exceeds 800 square feet in size (up 1,000 square feet )

Number of Bedrooms:

Not specified by State Standards.


Between between 2020 and 2025, owner occupancy requirements will not apply to new Accessory Dwelling Units. (applicable to new construction and conversion units) ~ SB13

As of January 1st, 2020

Utility connections:

Local health officer approval where a private sewage disposal system is being used, if required. (State requirements)

Permit Fees

SB13 Update: As of January 1st, 2020, local impact fees for ADUs will be reduced substantially statewide.


What is a Second Dwelling Unit?

A Second Dwelling Unit (aka, “in-law” or “granny” unit) is an additional dwelling located on the same lot as a single-family residence which contains separate living/sleeping, sanitary, and cooking facilities. A second unit may be located within the principal dwelling or can be in a detached accessory building. The unit cannot be sold separately from the principal dwelling.


What are the Rules for Legal Conforming or Non-conforming Second Dwelling Units?

A an existing unit constructed and established prior to adoption of zoning regulations for second units may be protected under Section 14.16.060 (Conservation of Dwelling Units). To determine applicability, the owner must produce evidence that the unit was either legally established prior to 1950 (prior to adoption of the City’s first Zoning Code) or constructed prior to January 1, 1991. This may require submittal of documentation and a zoning determination request to the Planning Division. Typically, evidence is provided through building permit records. If such records do not exist, evidence could include documentation of the residential building record used for assessment purposes, which may be obtained from the County Assessor’s office.


The second unit must have a separate entrance from the principal dwelling. In order to maintain the appearance of a single-family residence, the entrances to the second unit and principal dwelling unit cannot be located on the same side (elevation) of the principal dwelling most parallel to the front property line.

Allowed Zones:

*** Beginning in 2020, according to state law, all residential zoning districts, including single-family and multi-family, are allowed to build Accessory Dwelling Units. ***

As of January 1st, 2020

Kitchen / Bath:

A suitable kitchen facility must be separate from the bathroom and provide a sink, cooking facility (more than a hot plate or microwave), refrigeration and storage. A suitable bathroom facility must include a toilet, sink and bathing facilities.

Legalize Existing Unit

Can an Existing (Unpermitted) Second Unit be legalized?

Yes. The unit must meet all requirements for a second unit, and obtain planning review of a Second Dwelling Unit. Building permit fees to legalize an existing unauthorized second unit will be tripled and planning fees will be doubled.

Residential Building Code:

The California Building Code (CBC) 2019 is adopted.

San Rafael City Planning Offices

San Rafael Planning Office

Hours: 8:30 a.m. - 5:00 p.m. Monday-Friday

1400 Fifth Avenue, Top Floor San Rafael, CA 94901 San Rafael, CA 94901

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Kathleen Murphy

Bradley Real Estate

Lic. #00952533

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Karyn Jones

Program Representative

Call Now (760) 496-5959

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Costs / ROI


* upon completion of ADU


* based on local average price per sqft


* estimated by location


* 30 years / 5% interest rate / 20% down payment


Appreciation Estimate = (Base Value: $) / (Home's Living Space: sqft) * (ADU's Living Space: sqft)

Rental Estimate = (Rent Per Sqft: $5.02) * (ADU's Living Space: sqft)

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