All properties zoned for single family or multi-family with the following zoning codes are eligible for ADUs. Check the zoning of your property. 

  • R-1 (most single family homes)
  • R-2, R-E, R-M, RMD (duplexes & multi-family)
  • OS (open space) when single-family residential is a permitted land use:
  • PC (planned community when single-family residential is a permitted land use:

Number of units

1 ADU and 1 Jr. ADU (JADU) are allowed on each property.

Building size

ADUs must be at least 150 square feet in size. The maximum size is 500 sq. ft. for a JADU, 850 sq. ft. for a one bedroom ADU or 1,000 sq. ft. for a 2+ bedroom ADU. Attached ADUs cannot be greater than 50% of the existing home’s floor area.

Building height

Detached ADUs can reach a maximum height of 16 feet. Attached ADUs can reach the same height as the main structure, assuming they comply with municipal code (including daylight plane).


Conversion of existing unfinished basement space can be used for an attached ADU.


Minimum setbacks of 4 feet from the side and rear lot lines, as well as 6 feet from any existing structures are required for detached ADUs.


No additional parking is required for ADUs. Even when converting a garage or carport, replacement parking is not required.

Should you decide you want to build additional parking, covered parking provided for the ADU is included in the total floor area for the site, but not included in determining the max size for the ADU.


Owner occupancy is not a requirement for permitting an ADU from January 1, 2020 until January 1, 2025. This is a great opportunity for rental property owners to increase their yields in a cost-effective way.


While long-term rentals are permitted for ADUs, short-term rentals (e.g. Airbnb) are not permitted in Sunnyvale.