Global Announcement Text

Fremont, California: ADU Regulations

Are ADUs allowed in Fremont:


Date Updated:



R-1, R-2, R-3, R-G, OS

Number of ADUs allowed:

On approved lots, only one ADU is permitted.

Types of ADUs allowed:

In Fremont, there are two types of ADUs, Standard Accessory Dwelling Units (SADUs) and Junior Accessory Dwelling Units (JADUs). SADUs are detached structures on the property or can be attached to the primary residence. JADUs, on the other hand, are created from existing living space (such as a bedroom) and are smaller than 500 sq. ft.

Lot size:

ADUs in R-G zoning districts are not permitted on lots larger than 7,500 sq. ft. or on lots larger than 6,000 sq. ft. in R-3 zones.

ADU size:

Refer to the following parcel size (square feet) and maximum floor area of potential ADU (square feet) guidelines: Less than 5,000 - 500; 5,000-7,999 - 700; 8,000-9,999 - 800; 10,000-19,999 - 900; 20,000-39,999 - 1,050. 40,000 or more - 1,200.


SADUs must have a separate and complete kitchen

JADUs must include an efficiency kitchen, not located within a closet.


SADUs must have separate sanitation facilities.

JADUs may include a bathroom or share bathroom facilities within the primary dwelling.


Detached ADUs must be separated from other residential structures by at least 10 feet. SADUs shall maintain a 5' minimum setback from rear and side property lines. 


For JADU there are no additional parking spaces required. SADUs require one parking space (garage or carport, paved extended driveway, or other location on the property) per bedroom unless the unit is located within one-half mile of public transit (BART stations, Centerville's ACE Station, or bus stops) or one block of a public subscription car share parking lot, is within the Mission San Jose or Bryant Street Conservation Areas, is on an historic register resource property, or is located in an area where on-street parking permits are required but are not offered to ADU occupants.

Fire Safety:

Setback from main residence be reduced to eight feet if one residence is equipped with fire sprinklers or six feet if both structures are equipped. Garage conversion SADUs are exempt from setback requirements provided any walls within the setback area comply with applicable building and fire codes. Other exceptions may apply.

Note: Fire Department regulations should be assessed on a project by project basis.

Shape, materials, and style:

ADUs must feature residential designs, building materials and colors compatible with the primary residence.


ADUs must follow height limits applicable to the principal residence.


All ADUs must have a separate exterior entrance that cannot be located on the front of the primary dwelling.
Outside stairways to the ADU shall not be located in the front of the primary dwelling.
JADUs also require interior access to the primary dwelling and may be a door with a double lock.

Design review:

An application for an ADU that meets the applicable standards in the Fremont Municipal Code (FMC) is subject only to ministerial review and approval. However, design review requirements are applicable for new construction and a Ministerial Design Review Permit is required.

Note: Historic Neighborhoods or Districts should be assessed on a project by project basis.


The property owner must reside either in the principal residence or in the ADU. ADUs must be rented for terms of at least 30 days. A deed restriction must be filed with Alameda County prohibiting the sale of the ADU as a separate residence, and verifying that the unit complies with the City’s requirements.

Utility connections:

Alameda County Water District and Union Sanitary District permits may be required.

Note: Drainage and sewer connections should be assessed on a project by project basis.

Permit Fees:

A fee is required for the building permit and may be required for other permits. For more information click here.


“Accessory Dwelling Units (ADUs—also known as “secondary dwelling units” or in-law apartments) are attached or detached residential dwelling units that are subordinate to a principal residence on the same lot and that provide complete independent living facilities for one or more persons. ADUs include permanent provisions for living, sleeping, eating, cooking, and sanitation.”

Historic Requirements:

Architectural approval must be granted by the Historical Architectural Review Board for lots on the National Register of Historic Places, the California Register of Historical Resources, or any local list of historic resources.


ADUs do not count toward the density requirements in the General Plan or zoning regulations.

Allowed Zones:

ADUs are not permitted in buildings with more than one principal residence (duplexes, triplexes, etc.).


ADUs are not allowed on “constrained” land, where development is limited due to conditions determined to be detrimental to public health, safety, and welfare.

ADU Manual / Guide:

Potential Rental Income:

According to, Accessory Dwelling Units in Fremont, CA can possibly generate $24,000+ in rental income.

Important Note: Rules and regulations are updated and changed frequently. It’s one of our jobs to be up to speed and navigate those regulations. Let us know if our website isn’t up to date or if you have any information that could help. Cheers!