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Accessory Dwelling Unit (ADU) City Regulations for
San Jose, CA
San Jose is a large city surrounded by rolling hills in Silicon Valley, a major technology hub in California’s Bay Area. If visiting the area be sure to check out Rosicrucian Egyptian Museum or spend the day at the beautiful Municipal Rose Garden.
One Accessory Dwelling Unit is allowed per lot. Attached ADU, detached ADU and conversion ADUs are allowed
5,445 sq.ft. min.
Maximum ADU Floor Area:
Attached: no more than 50% of primary dwelling floor area
Detached: 5,445 to 9,000 sq.ft lot, 600 sq.ft. ADU 9,001 to 10,000 sq.ft. lot, 650 sq.ft. ADU >10,001 sq.ft. lot, 800 sq.ft. ADU
Number of Bedrooms:
A studio or only one bedroom, maximum 400 square feet permitted.
60 sq.ft. max for entire unit.
Require separate full bathroom and kitchen facilities (permanent range, counters, refrigerator, sink). Max. 1 bathroom.
One space in addition to the required parking spaces for the primary dwelling, unless ADU qualifies for exemptions. (The list of exemptions below)
1) The parking space must be located on a mud-free, dust free surface.
2) The parking space must be located outside of the front and side setbacks of the property, except that the parking space may be allowed in the front setback if it is located within a garage driveway apron that is a minimum of 18 feet in length
Same as the zoning district. Also subject to the provisions below. Single-story unit – Rear setback can be reduced to fit, if ADU occupies 50% or less of area between 5 feet and required REAR setback. Above an attached garage – Rear and side setback can be 5 feet. Garage conversion – If an existing legal garage is converted to an ADU, no additional setback is required. Riparian – For a lot greater than or equal to ½ acre, a minimum 100 foot riparian setback is required.
Attached: must comply with standards of underlying zoning district. One story, 18 feet maximum and 14 feet 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 garage meets Building and Fire Code; but not be attached to other accessory buildings.
Rear Yard Coverage:
Cannot exceed 40% of yard.
Detached units do not need to meet any specific design standards, provided there is visual compatibility with existing primary dwelling. Attached ADUs and detached ADUs on properties listed on the Historic Resources Inventory must incorporate architectural style and elements of the primary dwelling.
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.