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San Jose ADUs

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San Jose ADU Guidelines Last Updated 08/21/19


The city government of San Jose has updated its local zoning codes to comply with the State ADU mandate.
The California Building Code (CBC) 2016 is adopted with the following amendment(s): 29806, 29807


City Hint: In The City of San Jose, permitting fees for ADUs have been reduced recently due to a new waiver program to incentivize housing development in the city.

City Hint: The city permitted a total of 190 ADU project(s) in the past year of 2018, which is below the average compared to other cities in California.


Number of ADUs allowed:

One Accessory Dwelling Unit is allowed per lot.

Types of ADUs allowed:

Attached ADU, detached ADU and conversion ADUs are allowed.

Lot size:

A minimum lot size of 3,000 square feet is required.

ADU size:

The maximum ADU size is determined by lot size: (a.) Lots of 3,000 to 5,444 square feet, 600 square feet is allowed. (b.) Lots of 5,445 to 9,000 square feet, 700 square feet is allowed. (c.) Lots of 9,001 to 10,000 square feet, 800 square feet is allowed. (d.) Lots of 10,001 square feet, to Up 900 square feet is allowed.


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.


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

Fire Safety:

Fire sprinklers are required if required in the primary home.

Shape, materials and style:

Detached units do not need to meet any specific design standards. Attached ADUs and detached ADUs on properties listed on the Historic Resources Inventory must incorporate architectural style and elements of the primary dwelling.


Attached – Same requirement as the zoning district Detached - One story, 18 feet maximum and 14 feet average (20.30.150.J.5)

Design review:

Ministerial review process. Allowed by right in accordance with zoning and building code.

Number of Bedrooms

A studio or only one bedroom, maximum 400 square feet permitted.


Unit is not intended for sale separate from the primary residence and may be rented. (State requirements)

Utility connections:

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


Front Door for Attached Unit cannot be on same street-facing façade as that of primary residence, unless all other locations for placing front door would require a pathway that is unobstructed, clear to the sky and extending from a street to the front door. (20.30.150.K.3)

Rear Yard Coverage:

Note that the current rule of a maximum 40% coverage of the rear yard will continue to be required.

Allowed Zones

Please refer to the following Zoning Code Section for information related to ADU's: -- You could also review this webpage:

Storage / Closet

Maximum of 60 square feet of closet space allowed per entire ADU.

Lot Coverage

Rear Yard Coverage

The cumulative total of the rear yard covered by detached unit, accessory buildings, and accessory structures cannot exceed 40%. (20.30.150.J.7)

Kitchen / Bath

(a) Kitchen required (sink, food storage, permanent cooking facilities)
(b) Maximum one bathroom


Attached – (1) Share a wall or (2) have integral roof structure with primary residence, and separated by no more than 10 feet. (20.30.150.J.2)

Detached - (1) Must be located in the rear yard, with a 6-foot separation from the main residence. (20.30.150.J.3 & 4) (2) May be attached to detached garage, if it meets Building and Fire Code; but may not be attached to other accessory buildings.(20.30.150.J.6)


PARKING EXEMPTION (20.30.150.I): No additional parking shall be required for a Secondary Dwelling that meets any of the following criteria:
The Secondary Dwelling is located within one-half (1/2) mile of, and has a path of travel that is always publicly accessible to a Site containing an existing public rail-transit station or at least one (1) public bus route with a frequency-of-service interval of fifteen (15) minutes or less during the morning and afternoon peak commute periods.
The Secondary Dwelling is located within a Historic District identified in the City’s Historic Resources Inventory as defined in Chapter 13.48 of Title 13 this Municipal Code.
The Secondary Dwelling is part of the existing primary residence or part of an existing Accessory Structure.
When on-Street parking permits are required but not offered to the occupant of the Secondary Dwelling.
When there is a motor vehicle that is operated as part of a regional fleet by a public agency or publicly leased motor-vehicle-sharing organization and provides hourly and daily service located within one (1) block of the Secondary Dwelling.

Residential Building Code:

The California Building Code (CBC) 2016 is adopted with the following amendment(s): 29806, 29807

San Jose City Planning Offices

City of San Jose, Development Services Permit Center

200 E Santa Clara St., San Jose, CA San Jose, CA 95113

San Jose ADU Marketplace

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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

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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: $4.18) * (ADU's Living Space: sqft)

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