All ADU Regulations

Milpitas, California

The Milpitas, California ADU regulation has been updated to comply with new state laws. Learn about the new requirements for permiting an ADU is Milpitas.

November 7, 2020
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All properties zoned for single family, duplex or multifamily use may be eligible to build ADUs. Lots in the 'H' Hillside Combining District may be subject to additional requirements, depending on the side of the crestline.

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 1 ADU per 4 existing residential units. No more than 2 detached ADUs are permitted per lot.

Building size

Maximum square footage is determined by your lot size, zoning and ADU type:

  • 500 sq. ft. for a Jr. ADU (JADU)
  • 800 sq. ft. for an ADU if the existing home has reached the maximum lot coverage and floor area ratio
  • 850 sq. ft. for a 1 bedroom ADU
  • 1,000 sq. ft. for a 2+ bedroom ADU
  • An attached ADU may not exceed 50% of the existing living 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).

ADUs in the Hillside Combining District have different maximum heights, depending on the side of the crestline:

  • West side: 17 ft. in height and one story from the lowest finished grade to the highest ridgeline of the building
  • East side: 27 ft. and two stories from the lowest finished grade to the highest ridgeline of the building


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 setback is required for an ADU that replaces an existing structure and is located in the same location and to the same dimensions as the structure being replaced.


No additional parking is required for JADUs or for conversions of garages or carports. For each detached or attached ADU, 1 off-street parking space is required, unless the ADU is located within 0.5 mi. walking distance from public transit. That parking may be uncovered tandem parking in a driveway.


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, homeowners may be required to sign a deed restriction preventing short-term rentals (e.g. Airbnb for less than 30 days).


Do you have a utility easement over your property? Do you have special setbacks? Reach out to us and we’ll help you build a custom ADU to fit your unique property characteristics and local regulations!

Design and build with confidence.