San Bruno has combined all of its ADU information on one page

San Bruno ADU Checklist



  • Lot must be zoned single-family or multifamily and contain an existing, single family dwelling
  • No more than one ADU may be located on any residential lot, and no ADU shall be approved if located on a lot with an excess housekeeping unit
  • Lot must be located outside of the 70 decibel Airport noise contour per Airport Land Use Compatibility Plan for SFO (see map on the back)
  • If the ADU is located within the 65 decibel Airport noise contour, the interior noise level must be reduced to 45 decibels.

Detached ADU:

  • The floor area of the detached ADU shall not exceed 640 square feet ☐
  • The ADU side and rear setbacks shall be at least one foot from the lot lines, and shall be sufficient for fire safety, as determined by the Fire Marshall and Building Official


Onsite parking is not required for an ADU in any of the following instances: ☐

  • The ADU is located within one-half mile of public transit (see map on the back) ☐
  • The ADU is located in an architecturally and historically significant historic district ☐
  • The ADU is within the existing primary residence or existing accessory structure ☐
  • On-street parking permits are required but not available to the ADU occupant ☐
  • When there is a car share vehicle located within one block of the ADU


San Bruno ADU Application

San Bruno ADU Ordinance

City of San Bruno

City of San Bruno Community Development