Global Announcement Text

Cupertino, California: ADU Regulations

City or County:

Cupertino, California

Date Updated:

11.25.2020

Zoning:

Accessory dwelling units are permitted on lots within any residential or mixed-use residential zoning district. The lot must have an existing single family dwelling unit or if zoned multi-family or mixed use residential, at least one residential unit. If the lot is vacant, an accessory dwelling unit may only be proposed in conjunction with the development of at least one residential unit.

Types of ADUs:

Attached, Detached, Garage Conversion and Junior

Stories:

A two-story ADU is only allowed if you are converting a portion of existing second story space into an ADU.

Lot Size:

N/A

Maximum ADU Floor Area:

Depends on district and ADU type. After 800 sq.ft., requirements change.

Conversions: 50% of existing living space

Single Family Detached/Attached: Studio/1 bedroom: 850 sq.ft; 2+ bedroom: 1,000 sq.ft. Must meet Floor Area Ratio and Lot Coverage

Multi; Detached: 800 sq. ft.

FAR Requirements:

ADUs will count towards the FAR although all single family homes are permitted to construct an ADU ≤ 800 sq.ft (living area, exclusive of decks, etc.) as follows:
• Properties at maximum FAR - ADU sq.ft. is not limited by lot coverage, FAR, and open space requirements
• Properties at less than maximum FAR - ADU sq.ft. applies to FAR till FAR limit; ADU balance up to 800 sq.ft. is not limited by lot coverage, FAR, and open space requirements
• ADUs > 800 sq.ft. are limited by lot coverage, FAR, and open space requirements
• ADUs in multi-family developments are not limited by lot coverage, FAR, or open space requirements

Lot Coverage:

Must comply with dwelling regulations for underlying zoning district.

Bedroom:

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

Storage:

No min/max

Kitchen:

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

Bath:

Require separate bathroom facilities.

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

Parking:

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.

Setbacks:

Single Family Internal Conversion: per underlying zoning 

Single Family Detached ( 800 sq.ft.): Front per underlying zoning; Rear and sides 4’
Single Family Detached (> 800 sq.ft.): must comply with Accessory Structure Ordinance
Single Family Attached: Front per underlying zoning; Rear and sides 4’

Multi Family Internal Conversion: no increase in height of existing structure
Multi; Detached: Front per underlying zoning; Rear and sides 4’

Height:

Detached: 16' (note that Single Family over 800 sq.ft. must comply with Accessory Structure Ordinance)

Attached/Conversion: Comply with underlying structure

Location:

Must follow guidelines of underlying zone.

Number of Units:

Single Family Internal Conversion: two units are allowed if one is a JADU and one is a detached 800 sq.ft. ADU
Single Family Detached (800 sq.ft.): two units are allowed if one is a JADU and one is a detached 800 sq.ft. ADU
Single Family Detached (> 800 sq.ft.): Only one ADU of this kind is allowed. A JADU is not allowed in addition to these
Single Family Attached: Only one ADU of this kind is allowed. A JADU is not allowed in addition to these

Multi Family Internal Conversion: The greater of: 25% of existing dwelling units or 1 ADU
Multi; Detached: No more than 2 ADUs

Rear Yard Coverage:

N/A

Design:

Should be compatible with the architectural style and materials of the primary residence

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

Entryways:

Independent outside access must be provided without going through the principal unit and must be on a different elevation than the entrance to the principal unit • There can be no connection with the principal unit, except for a JADU that shares a bathroom with the principal unit • Independent outside access must be provided without going through the principal unit and must be on a different elevation than the entrance to the principal unit • There can be no connection with the principal unit, except for a JADU that shares a bathroom with the principal unit

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!