San Jose CA ADU Guidelines

Accessory Dwelling Unit (ADU) City Regulations

Exciting news regarding ADUs!

Last night, the San José City Council approved amendments to the ordinance for backyard homes—also known as Accessory Dwelling Units (ADUs). The amendments align with State bills that passed this year, focusing on cutting red tape and impact fees, and easing requirements.

In other words: it’s going to be even simpler to build a backyard home on your property to collect additional income for your family, while helping add desperately-needed homes to our city’s housing stock. 

The new ordinance goes into effect today. Learn more about what might work on your lot at www.sanjoseca.gov/ADUs.

What changes were made? Check them out: 

  • There is no longer a minimum lot size requirement for ADUs.
  • You are allowed to build an ADU in more types of single-family zoning districts, as well as multi-family and mixed-use zoning areas.
  • Junior ADUs (JADU)—an ADU within the main home’s footprint, including attached garages—are now allowed.
  • ADUs can be bigger, with up to 2 bedrooms:
         Lot Size      Maximum ADU sizeMaximum Bedrooms
         Up to 9,000 square feet      1,000 square feet2
         Greater than 9,000 square feet      1,200 square feet2
  • Attached ADUs can exceed 50% of the main home area as long as the ADU is smaller than 800 square feet.
  • ADUs and other backyard structures can exceed 40% of the rear lot coverage as long as the ADU is smaller than 800 square feet.
  • You no longer have to acquire a special permit for ADUs on properties listed on the City’s Historic Resources Inventory.
  • You no longer need to offer replacement parking for garage conversions.
  • ADUs that are rentals must be rented for a term of no less than 30 days.
Separate from the ordinance, the following new laws go into effect on January 1, 2020:
  • You do not have to pay any parkland or school impact fees on ADUs smaller than 750 square feet.
  • The City must act on permit applications within a 60-day window. If the City has not taken action within the 60-day window, permit will be considered approved.
  • If you currently have an unpermitted ADU on your property, you can qualify for a mandatory 5-year stay on any agency enforcement, as long as your ADU meets health and safety standards.
Find the latest information and updates to ordinance changes here
Check out more ADU news here.


R-1/R-2 with only a one-family dwelling on lot.

Lot size:

5,445 sq. ft. minimum

Maximum ADU Floor Area:

Attached:  no more than 50% of primary dwelling floor area

Detached: Less than or equal to 9,000 sq.ft. lot, 600 sq. ft. ADU

9,001 to 10,000 sq. ft. lot, 650 sq.ft. ADU

Greater than 10,000 sq.ft. lot, 800 sq.ft. ADU

Number of Bedrooms:

Studio layout permitted; otherwise one bedroom 400 sq. ft. max.


60 sq.ft. max for the entire unit.


Require separate bathroom and kitchen facilities (Permanent range, counters, refrigerator and sink). Max. 1 bathroom.


One space in addition to required parking spaces for primary dwelling, unless secondary unit qualifies for exemptions.  Must be located on mud-free, dust-free surface, outside of front and side setbacks of property.  ADU parking space may be located within garage driveway apron that is minimum of 18' in length.


Same as the underlying zoning district with the following provisions:

Single-story unit: rear setback can be reduced to 5' if ADU occupies 50% or less of area between 5' and required rear setback.

Attached/above an attached garage: rear and side setback can be 5’.

Garage conversion: if existing legal garage converted to secondary unit, no additional setback required.

Riparian: for ½ acre lots or more, minimum 100' riparian setback is required.


Attached: must comply with standards of underlying zoning district.

Detached: one story, 18' max with 14' average.


Attached: must share wall or have integral roof structure with primary residence, and separated by no more than 10 feet.

Detached: must be in rear yard with 6’ separation from primary dwelling. May be attached to detached garage, if meets Building and Fire Code; but not be attached to other accessory buildings.

Rear Yard Coverage:

Cannot exceed 40% of yard.


Must be constructed with facade materials similar in texture and appearance to primary dwelling, including but not limited to roofing, siding, windows, and doors. Roof pitch and form should match primary dwelling to blend with one-family dwelling architecture.


Door cannot be on same street-facing facade as primary dwelling, unless all other locations for placing front door would require pathway that is unobstructed, clear to the sky and extending from a street to front door.

For more ADU Information:


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