STATEWIDE UPDATE: New California ADU Bills SB13, AB68, AB881, AB670 have passed. These laws will create more options for building an ADU in San Rafael in 2020. To prepare for the upcoming changes use our ADU Services to learn how these laws will effect your property!
Schedule ADU Consultation (415) 843-2387 ext: 650

San Rafael ADUs

Everything about building Accessory Dwelling Units in San Rafael, CA

Research local zoning codes for ADU design
Calculate returns and costs to get financing
Estimate your project costs and timeline

Check your property to get zoning info & price quotes for ADU feasibility & design services:

I'm interested in

Last Updated 08/11/19


The city government of San Rafael will approve ADUs under California's statewide mandated regulations.
The California Building Code (CBC) 2016 is adopted with the following amendment(s): 1944, 1943
Relevant state bill updates for SB13, AB68, AB881, AB670 are shown in green below.


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:

One ADU per primary home.

AB68 & AB881 Update: Properties which convert existing space to create ADUs may be eligible for one ADU -AND- one JADU.

Types of ADUs allowed:

Detached, Attached, and junior ADUs are allowed.

Lot size:

A minimum 5,000 square foot lot size developed with a single-family residence is required in order to qualify for an ADU. Only one ADU (or junior ADU) is allowed in addition to the main unit per lot.

AB68 & AB881 Update: Properties will not be subject to minimum lot standards by ordinance or of the applicable zoning district.

ADU size:

The minimum dimensions for accessory dwelling units are as follows: Studio: 220 square feet (not including closet and bathroom). One, plus bedrooms: Main room - 120 square feet / 7 FT min. dimension. Other rooms (except kitchens) - 70 square feet / 7 FT min. dimension. Ceiling height for habitable rooms is 7.5 FT , and kitchen, hallways, & bathroom is 7 FT At no time shall the size of the ADU exceed 40% of the gross square feet of the principal dwelling, excluding the garage, except that the floor area of a ADU may be a minimum of 500 square feet, regardless of the size of the house. The maximum size of a ADU is 1,000 square feet provided that any ADU over 800 square feet in size also requires Planning Commission Use Permit approval.

AB68 & AB881 Update: Properties will be allowed up to 850 square feet for a one bedroom or up to 1,000 square feet for a two bedroom ADU.


Accessory dwelling units added or attached to the principal residence shall be subject to the setback requirements otherwise applicable to the principal residential structure. Accessory dwelling units constructed as a separate detached accessory building shall be subject to the setback requirements otherwise applicable to accessory structures. Note that Use Permit and/or design review permits may be required for ADUs in accessory structures that are located within the required setbacks.

AB68 & AB881 Update: The maximum required setback for a detached new construction ADU shall be no more than 4 feet from the rear or side property lines.


Studio or 1-bedroom ADU: 1 space 2 or more-bedroom ADU: 2 spaces, Parking for the ADU may be uncovered. One parking space for the ADU may be in the front yard with a paved area between the driveway and the nearest side property line, parallel to the driveway. On parcels having frontage on a street with a paved width of at least feet, one parking space for the ADU may be tandem (located behind a parking space in the principal dwelling), located on a driveway which is at least feet in length behind the property line.

AB68 & AB881 Update: Properties which convert an existing garage will not be subject to replacement parking requirements.

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.


The property owner must reside in either the principal or the ADU.
A deed restriction must be recorded with the County Recorder so that future owners of the property will be aware of the requirements (such as owner occupancy). Proof of retardation must be submitted to the Planning Division prior to issuance of a building permit or after ADU application has been processed.

SB13 Update: Owner-occupancy requirements for ADUs will be voided statewide for 5 years.

Utility connections:

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

Permit Fees

SB13 Update: 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.

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) 2016 is adopted with the following amendment(s): 1944, 1943

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

Featured AgentReal Estate

Kathleen Murphy

Bradley Real Estate

Lic. #00952533

Contact Kathleen Murphy about ADUs in San Rafael. Send a text message:

San Rafael ADU Marketplace

How can I get my ADU built?

Use our ADU Services and Marketplace to get expert assistance, permit-ready ADU designs and on-site contractor estimates on one platform.

Fast and low cost ADU design services

Search local contractors to get estimates

Featured Financing Program

ADU Financing

CA Statewide

Tailored to ADU construction.

Based on project size & appreciation.

Learn how to qualify.

Karyn Jones

Program Representative

Call Now (760) 496-5959

Read San Rafael Housing Market Update

Featured ArticleSan Rafael, CA

San Rafael approves fair housing ordinance 2018-12-06

Featured ArticleState of CA

What are Accessory Dwelling Units? California Department of Housing and Community Development 2017-05-15

Featured ArticleState of CA

[CA] Governor Brown Issues Legislative Update 2017-10-08

ADU Guides

ADU Services

A recent customer review:

"Quick response time and very knowledgeable about the ADU laws in California. Would definitely recommend your service to a friend or anyone that's interested in building an ADU. "

Kam in Hayward, CA

Customer since July, 2019

Learn about ADU Services

Estimate ADU Potential
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)

How can I get my ADU built?

Our ADU Services and ADU Marketplace provide the fastest and lowest cost way to get started with your ADU project.

How does it work? Get started on your project with expert assistance and without commitment using our customized ADU Property and Design Reports as your first step. Then, get on-site visits from local contractors who can provide you with guidance and estimates for your ADU project.

Our Key Advantages

Compare all the costs and services in one place to find the best fit for your needs and budget

Order ADU zoning research, permit-ready designs and contractor estimates on one platform

Get started on your timeline and your terms, without commitment

The fastest and lowest cost way to get started with your ADU project

Our ADU Process

Expert Feasibility & Zoning Research

Use our ADU Property & Design Reports as a starting point to plan your ADU project. Our experts will do the legwork with your city or county planning office and design custom ADU concepts for your property and your needs.

Find contractors to build your ADU

Use our local contractor database to get on-site visits and cost estimates to compare services for your ADU project.

Getting your designs ready for city permitting and construction can speed up your ADU project and reduce unforseen costs later on in the process.

Check your property to get zoning qualification & price quotes for ADU Services:

Access cost estimates, zoning analysis, design concepts and order ADU Services to get help with feasibility, design and permitting for your ADU project. Check your property to get started!

I'm interested in