Sonoma, CA Fence Regulations: Neighbor Fence Rules (2026)

Boundary fence disputes in the City of Sonoma are governed primarily by state law: California Civil Code §841, the Good Neighbor Fence Act. That statute presumes that adjoining landowners share equal benefit from any fence dividing their properties and, absent a written agreement otherwise, are 'equally responsible for the reasonable costs of construction, maintenance, or necessary replacement of the fence.' A landowner who intends to incur costs for a shared fence must give 30 days' prior written notice to each affected adjoining landowner, including a description of the problem, proposed solution, estimated cost, cost-sharing approach, and timeline. The presumption can be rebutted by preponderance of the evidence, and a court may then order an unequal share or no contribution. Local rules in SMC Ch. 19.46 (height, materials, sight triangles) still apply regardless of any private cost-sharing agreement. The City does not mediate private boundary disputes; remedies are pursued in civil court (Sonoma County Superior Court).