San Luis Obispo County, CA Building Setbacks & Zoning: Setback Rules (2026)

140 of the Land Use Ordinance sets minimum building setbacks for every land use category. Under Subsection D, the basic front setback for structures taller than three feet is 25 feet from the front property line, and residential uses follow that same 25-foot standard except shallow lots under 90 feet deep get 20 feet, and certain sloping or partially-developed blocks can adjust the front setback down to as little as 10 feet. Side setbacks under Subsection E are calculated as 10 percent of lot width: in urban and village areas that comes to a maximum of 5 feet on lots under an acre but never less than 3 feet, while lots of an acre or larger need a minimum of 30 feet; in rural areas the same 10 percent formula caps at 25 feet on lots under an acre (still never less than 3 feet) with the same 30-foot minimum on acre-plus parcels.

Rear setbacks under Subsection F are a flat 10 feet on lots under an acre and 30 feet on lots of an acre or larger, with an exception letting a residential accessory building or structure up to 12 feet tall sit as close as 3 feet to the rear property line or alley. Subsection A exempts fences and low decks/landscaping under 30 inches from these standards, and Subsection H allows specific projections like eaves, bay windows and porches to intrude partway into a required setback under the California Building Standards Code.