Cupertino, California: ADU Regulations
City or County:
Types of ADUs:
Attached, Detached and Garage Conversion
Limited to single story, however a second-story of a primary dwelling may be converted to an ADU as long as there is compliance with applicable landscape requirements to adjoining dwellings consistent with Section 19.28.120.
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. are 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.
Must comply with dwelling regulations for underlying zoning district.
No min/max, but must follow allowable density guidelines of lot.
Require separate kitchen facilities (permanent range, counters, refrigerator, and sink).
Require separate bathroom facilities.
Note: Drainage and sewer connections should be assessed on a project by project basis.
ADUs from converting existing space requires no additional parking. One additional off-street parking space shall be provided if the principal dwelling unit has less than the minimum off-street parking spaces for the applicable residential zoning district in which it is located, as required in Chapter 19.124 unless the unit meets the following requirements:
a. Is within one-half (1/2) mile of a public transit stop; or
b. Located in an architecturally and historically significant historic district; or
c. Occupant of the ADU is not allowed/offered a required on-street parking permit; or
d. Located within one block of a car share vehicle pick-up location.
Note: Any lost required parking spaces may be provided through any configuration on the lot (open, covered, enclosed, in tandem, or via mechanical lift) as long as all other parking regulations are satisfied.
Front: 20' in residential zones, 30' in agricultural zones.
Side: interior 3', street side on corner 15', street side on corner adjacent to key lot 20'.
Note: Fire Department regulations should be assessed on a project by project basis.
20' maximum, limited to 1 story.
Must follow guidelines of underlying zone. Minimum 5’ from principle dwelling.
Rear Yard Coverage:
ADU to be consistent with existing general plan and zoning land use designation for lot.
Note: Historic Neighborhoods or Districts should be assessed on a project by project basis.
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.