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San Jose, California: ADU Regulations

City or County:

San Jose, California

Date Updated:

12.10.2018

Zoning:

R-1/R-2/R-M

PD districts subject to approved development standards.

Types of ADUs:

Attached, detached and garage conversions

Stories:

Single-story and two-story ADUs permitted

Lot Size:

3,000 sq.ft. min.

Maximum ADU Floor Area:

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

Detached:

3,000 to 5,444 sq.ft. lot, 600 sq.ft. ADU

5,445 to 9,000 sq.ft lot, 700 sq.ft. ADU

9,001 to 10,000 sq.ft. lot, 800 sq.ft. ADU

>10,001 sq.ft. lot, 900 sq.ft. ADU

Lot Coverage:

Cannot exceed 40% of yard.

Bedroom:

2-bedroom ADU is allowed for units of 800 sq.ft. or greater, otherwise ADU can have only one bedroom or a studio layout. Bedrooms shall not exceed 400 sq.ft.

Storage:

60 sq.ft. max for entire unit.

Kitchen:

Require separate kitchen facilities (permanent range, counters, refrigerator, sink).

Bath:

Require separate full bathroom. Max 1 bathroom.

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

Parking:

1 space required for ADU occupants unless the property qualifies for an exemption under State law. If a garage has been converted, the main dwelling parking space must be replaced, as uncovered or in front or side setback areas. The homeowner may apply for a reduction of one space of required parking. Parking spaces may be configured on-site per state law.

Setbacks:

ADUs are subject to the setback requirements for a one-family dwelling in the zoning district in which the one-family dwelling is located, as set forth in this chapter except as follows:

  1. Conversion of Existing Accessory Building - No setback over the setback specified for an Accessory Building shall be required for an existing Accessory Building or garage, that is converted to a Secondary Dwelling unless required to meet current Building and Fire Code requirements.
  2. New detached Secondary Dwelling - No setback over the setback specified for an Accessory Building shall be required for the first story of a new detached Secondary Dwelling, unless required to meet current Building and Fire Code requirements.
  3. Second Story Secondary Unit - A minimum setback of five (5) feet from the side and rear lot lines shall be required for any second story of a detached Secondary Dwelling.
  4. Additional setback requirements may apply under the Building and Fire Codes or as a result of "no-build" easements.

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

Height:

Attached: must comply with standards of underlying zoning district.

Detached single-story: 18 ft. max

Detached two-story or 2nd story over garage: 22 ft. max

Location:

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.

ADUs on lots equal to or greater than one-half an acre in size, an ADU must be located more than one hundred feet from a riparian corridor as measured from the top of bank or vegetative edge, whichever is greater.

Rear Yard Coverage:

Cannot exceed 40% of yard.

Design:

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.

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

Entryways:

Door cannot be on the 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.

Source Code:

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!