Simi Valley Neighbor Fence Rules Rules (2026): What You Need to Know

California Civil Code Section 841, commonly known as the Good Neighbor Fence Law, establishes the legal framework governing shared boundary fences throughout California, including all properties in Simi Valley. The statute creates a presumption of equal responsibility: each adjoining landowner is presumed to bear an equal share of the reasonable costs of building, maintaining, and replacing a fence that sits on or along the common boundary line. This presumption is enforceable — a property owner who properly notifies their neighbor and then installs or repairs a boundary fence has the legal right to seek reimbursement for half of the reasonable cost, even if the neighbor initially refused to participate or contribute.

Before the initiating owner may recover costs from a neighbor, the law mandates that a written notice be delivered at least 30 days before work begins. The notice must be personally delivered or sent by first-class mail to the record owner of the adjoining property and must contain: a description of the condition of the existing fence or the reason a new fence is needed; a description of the proposed work including materials, dimensions, and specifications; the estimated total cost of the work; the proposed cost-sharing arrangement (commonly 50/50, though the parties may agree to any other split); and the proposed commencement date. If the neighbor does not respond or objects to the proposal, the initiating owner may proceed with the work and subsequently file a claim in Ventura County Small Claims Court (for disputed amounts up to $12,500) or in Superior Court for larger claims. The neighbor's failure to respond after receiving proper notice does not excuse them from the obligation to pay their proportionate share.

The equal-responsibility presumption is rebuttable. Either party may present evidence that sharing costs would impose undue financial hardship, or that the fence disproportionately benefits the initiating party rather than serving both equally — for example, where one side of the fence provides a privacy or safety benefit that is entirely one-sided. Courts weigh these arguments based on the specific facts presented at hearing. Separately, California Civil Code Section 841.4 prohibits spite fences — any fence or structure built or maintained unnecessarily exceeding 10 feet in height for the sole purpose of annoying an adjoining owner — and grants courts the power to order removal and award damages. Simi Valley's local zoning standards under Development Code Section 9-30.080 continue to govern the maximum permissible height of any fence constructed along a boundary line, and a private cost-sharing agreement between neighbors does not authorize a fence that exceeds those zoning limits.