San Diego County, CA Fence Regulations: Neighbor Fence Rules (2026)

Cost-sharing and maintenance of a fence on a shared property line in unincorporated San Diego County are not addressed by the County Zoning Ordinance, which only regulates height, location, and materials (Section 6708). Instead, California's statewide 'Good Neighbor Fence Law,' Civil Code Section 841, controls. Section 841 provides that adjoining landowners are presumed to benefit equally from a boundary fence and, unless they agree otherwise in writing, are presumed equally responsible for the reasonable costs of construction, maintenance, or necessary replacement. A landowner who intends to incur such costs must give 30 days' prior written notice to each affected adjoining landowner, describing the problem, the proposed solution, the estimated cost, the proposed cost-sharing, and the timeline.

The equal-responsibility presumption can be rebutted by a preponderance of the evidence that splitting the cost equally would be unjust, considering factors such as whether the financial burden on one owner is substantially disproportionate to the benefit. For the fence's height and placement, Section 6708 of the County Zoning Ordinance still applies: shared fences generally may be up to 72 inches in rear and interior side yards but only 42 inches in front and exterior side yards. Property-line disputes themselves are a civil matter; the County does not adjudicate boundary or cost-sharing disagreements.