ADU Zoning In Flux

NOTE: Our summary of ADU zoning located at http://urbangr.org/GRADURegs2018r2 is currently obsolete.

UPDATE: 2019-09 - It appears that the new status-quo is what is, the disappointing results of "Housing NOW" are what we have for the foreseeable future.


On 2018-12-18 the City Commission ratified changes to the zoning concerning ADUs. Theoretically there will be another set of changes, principally around permitting, sometime in March/April/May/....

Briefly, the changes on 2018-12-18 were:

  • Gross floor area ratio increased from 25% to 40%. The size of the ADU now has a hard limit of 850sq/ft. Minimum remains 400sq/ft.
    • This makes an ADU allowable with a primary structure with a gross floor area of only 1,000sq/ft. A primary structure of 2,125sq/ft allows an ADU of the maximum size.
    • Gross floor area includes all interior space with a ceiling height of 7ft or more; this includes the basement. Below grade space is typically not included in the normal sq/ft calculation for houses.
    • These limits may not be waived by the Planning Commission (previously a possibility).
  • Allowed height reduced from 25ft to 20ft, except when the ADU can be located 25ft from the rear lot line in which case 25ft is still allowed [is that ever possible? this is effectively a 20ft height limit]. Roof pitch matching that of the primary structure is still required.
  • Minimum lot area of 5,000sq/ft removed; lots now only need to be conforming to the minimum lot size of the zone.
  • Confusion between ADU size and Accessory Structure size has been resolved; an ADU doubles the sq/ft allowed in the Accessory Structure.
  • No change to permitting process.
  • No change to Owner Occupancy or Deed Restriction requirement.
  • No change to unit (1), occupancy (2), or bedroom (2) limit.
  • No change to parking requirement (+1).