All properties zoned for single family and multifamily use may be eligible to build ADUs.
Number of units
The number of ADUs you’re able to build depends on how your lot is zoned:
- Lots zoned for single family use may add 1 ADU and 1 Jr. ADU (JADU).
- Lots zoned for multi-family may add 2 new detached ADUs and 1 interior conversion ADU and 25% of the original number of units.
For detached ADUs, the maximum size is 1,200 sq. ft. Decks and porches, covered or uncovered, that are attached to the ADU are limited to 400 sq. ft. beyond the max size.
A JADU of up to 500 sq. ft. may also be incorporated into a detached ADU, bringing the maximum sq. footage of the combined ADU-JADU to 1,700 sq. ft.
Attached ADUs cannot be greater than 1,200 sq. ft. or 50% of the existing home’s floor area, whichever is less; however, a minimum of 800 sq. ft. is allowed even if the property has reached the maximum floor area ratio for the lot.
ADUs can reach a maximum height of 16 feet if the dwelling unit does not comply with the setback limitations for a single-family residence, as prescribed by the applicable zoning district.
If the ADU complies with the setback limitations for a single family residence, it is subject to the same height limitations as the single-family residence in the applicable zoning district, as measured from the lowest finished grade to the highest point of the structure.
Detached ADUs exceeding 16 ft. must incorporate a hip, gable, or other similar-styled roof design.
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 if they are within 0.5 miles of public transportation (a bus stop, train station, etc.). When converting a garage or carport, replacement parking is not required.
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 for less than 30 days) are not permitted in Santa Clara.