The Board of Supervisors voted unanimously Jan. 13 to adopt development code amendments for accessory dwelling units (ADUs) and junior ADUs that align county rules with current state law, county planning staff said.

Miguel Figueroa, land services director, and Vince Acuna, planning manager, presented the consolidated ADU chapter proposed for the county's development code. Acuna said the amendments include minimum unit sizes (200 square feet for ADUs, 150 square feet for junior ADUs) and building-height standards: 25 feet for attached ADUs, 18 feet for detached ADUs and 16 feet for by-right ADUs. Planning staff also noted state-required permit time frames: a maximum of 75 calendar days for a standard plan application and 45 calendar days for a preapproved plan application.

Supervisor Armendariz asked why the ADU heights differed from underlying zoning and raised feasibility questions for unincorporated areas without sewer service. Planning staff said the 25-foot limit for attached ADUs aligns with a typical two-story home and that 18 feet for detached ADUs reflects state law; staff acknowledged sewer costs can be prohibitive in areas not connected to sewer systems and said the county will coordinate with the water department and environmental health to explore options.

Acuna also said there are three predesigned ADU options currently available through county services to help reduce permitting and construction barriers.

After staff responded to questions and the hearing record showed no public comments, Supervisor Hagman moved the recommendation, the vice chair seconded, and the board approved the amendments unanimously.