County of San Diego

The regulations for the County of San Diego apply to properties that are not within an incorporated area of a City.  The County Regulations are very similar to other Cities in North County San Diego.  ADU builders in San Diego County are strongly encouraged to contact the appropriate Fire Department as soon as possible to ensure that their ADU complies with the required fire setbacks and to determine whether fire sprinklers are required or not.  See below link for County of San Diego ADU regulations.

https://www.sandiegocounty.gov/content/dam/sdc/pds/zoning/formfields/PDS-PLN-611.pdf

The County has developed some standard plans that can be used.  The building plans are approximately 85% completed.  See link below.

https://www.sandiegocounty.gov/content/sdc/pds/bldg/adu_plans.html