Neighbor guide

Who pays for a shared back fence in San Francisco?

Updated October 2026

Usually both of you. Under California Civil Code Section 841, adjoining owners are presumed equally responsible for the reasonable cost of building, maintaining or replacing a shared boundary fence, unless they agreed otherwise in writing. The owner who wants the work must give each neighbor 30 days' written notice first. On a small San Francisco lot, that can mean three or more neighbors.

What must the 30-day notice say?

Section 841 lists what to include:

• notice that the law presumes equal responsibility for reasonable costs,
• a description of the problem with the shared fence,
• the proposed solution,
• the estimated cost,
• the proposed way to split the cost,
• and the proposed timeline.

A written, itemized quote makes the estimated-cost part easy. We are glad to provide one you can attach.

Why does this come up so often in San Francisco?

On a typical narrow city lot, the back yard has a rear neighbor and two side neighbors, and sometimes the corners touch two more. One old fence can belong to four households. Good-neighbor fences, with boards alternating sides, are popular for exactly this reason: nobody gets the "back" side.

What does the split depend on?

It depends on any written agreement you already have, and on what counts as "reasonable." The law allows the presumption of equal shares to be rebutted, and a court can weigh things like whether the fence benefits one owner far more than the other, or whether one owner wants a much more expensive design. If one neighbor wants a 6-foot redwood fence and the other would be happy with the existing fence repaired, the extra cost may not be shared.

What if a neighbor will not respond?

Keep a copy of the notice and when it was delivered. Many neighbors agree once they see a clear plan and price. If not, some homeowners build on their own side of the line and pay the full cost, or seek mediation. Disputes over who owes what are a legal question; talk to a lawyer if it gets that far.

How do we handle a shared fence job?

• We can walk the line with both owners and quote the work so each sees the same numbers.
• We keep the fence on the agreed line and use a good-neighbor design if you want both sides finished.
• We schedule so both yards are accessible on build days.

Related: wood fences and fence repair.