All ADU Regulations

Redwood City, California

Redwood City has updated its ADU ordinance to comply with new state laws. Click here for up-to-date requirements to permit and build a Redwood City ADU.

September 23, 2021
Get Started  


All properties zoned for single family, duplex or 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 duplex or 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)
  • 850 sq. ft. for a 1 bedroom ADU
  • 1,000 sq. ft. allowed in lots zoned RH and R-1 of at least 10,000 sq. ft.
  • 1,000 sq. ft. for a 2+ bedroom ADU, regardless of the underlying zoning standards of the property
  • 1,200 sq. ft. for ADA-compliant (accessible) ADUs
  • 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).


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 ADUs. Even 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, 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.