San Marcos, CA Fence Regulations: Material Restrictions (2026)

San Diego County's Zoning Ordinance gives owners broad latitude on fence materials and opacity but imposes specific material restrictions. Under the Fencing and Screening Regulations (Section 6700 series), the degree of opaqueness or transparency of a fence or wall may be determined by the property owner, and dense landscaping can substitute for a view-obscuring fence if it achieves 100 percent screening within two years. Section 6708 restricts barbed and razor wire: razor wire, and barbed wire attached to supports constructed at an angle to the vertical, are permitted only as a security measure for the purpose of protecting high-value agricultural uses, or commercial or industrial uses. On large rural lots (one gross acre or more in the A70, A72, RR, S82, S88, S90 and S92 zones), open fences of woven or barbed wire, wrought iron, pipe corral, or rails may be 72 inches high in the front or exterior side yard. Where 72-inch-plus open fences are allowed, angled razor/barbed wire at the top is not counted in the fence height calculation provided its vertical height does not exceed 2 feet (Section 6708(j)). Separately, the County Building Division handout PDS-070 requires that, in Wildland-Urban Interface areas, any portion of a fence within 5 feet of a building be non-combustible or approved fire-retardant material meeting Section 707A of the County Building Code - effectively a fire-driven material restriction near structures.