Cupertino, CA

Accessory Dwelling Unit (ADU) City Regulations



Lot Size:

Detached: lots greater than 10,000 sq.ft.

Attached: lots smaller than 10,000 sq.ft. (however, it may be detached if the proposed architecture, colors, materials etc. consistent with main house).

Maximum ADU Floor Area:

Min. 150 sq.ft. and limited to 10% of net lot area up to 1,000 sq.ft., or 50% of existing living space of main dwelling, whichever is more restrictive.

Number of Bedrooms:

No min/max, but must follow allowable density guidelines of lot.


No min/max


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


Require no additional parking, otherwise must have additional parking space onsite if less than minimum off-street parking spaces available for the main house.  Parking exceptions apply.


Front: 20' in residential zones, 30' in agricultural zones.

Rear: 3'

Side: interior 3', street side on corner 15', street side on corner adjacent to key lot 20'.


Attached:  Limited to first floor.

Detached: 20' limited to 1 story.


Must follow guidelines of underlying zone.

Rear Yard Coverage:

30% Max


ADU to be consistent with existing general plan and zoning land use designation for lot.


Independent outdoor access must be provided without going through the principal dwelling. Where second-story ADU allowed, entry shall not be provided by exterior staircase. All access to ADU to be screened from public street.

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