San Bernardino County, CA Accessory Structures: ADU Rules (2026)

Under San Bernardino County Code §84.01.060, ADUs are allowed on any lot with an existing or proposed single-family dwelling. Only one ADU per parcel is allowed (plus one JADU), with a minimum 10-foot separation between the ADU and the primary dwelling. One parking space is required per ADU (waived for ADUs under 750 sq ft, within a half-mile of transit, or in other state-mandated exemptions), and tandem parking on the driveway is allowed. For multifamily properties, a minimum of one ADU and a maximum of 25% of the existing unit count may be created within an existing complex. The County is required to approve or deny a complete ADU application within 60 days under §84.01.060(L)(2) where there is an existing single-family or multifamily dwelling on the lot. The ordinance implements California Government Code §65852.2 and §65852.22 with ministerial review. JADUs are capped at 500 sq ft within the walls of the primary single-family dwelling and require owner-occupancy of either the primary or JADU recorded by deed restriction. Setbacks for new-construction ADUs are 4 feet (side/rear); existing setbacks are preserved for conversions. Maximum detached ADU size is 1,200 sq ft.