Fence Rules, Permits & Repair vs. Replacement on the Peninsula

Across Palo Alto, Menlo Park and Mountain View, the things that pull a fence into permit territory are height, material and location — not a percentage of the fence you touched.

That last point is worth stating plainly, because it circulates as folklore: none of these three cities publishes a "more than 50% replaced counts as new" threshold for fences. We looked for one in each city's current code and fence guidance and it is not there. What changes the answer is going taller, switching to a material the city treats differently, or moving the line — not how many boards came off.

• Height. Every city has a limit that depends on which yard you are in. Staying at or under the existing compliant height is the quiet path.
• Material. Mountain View treats wood differently from everything else. Menlo Park exempts wood fences under a certain height from a building permit.
• Retaining walls are not fences. If the structure holds soil back, it is a wall, and it is treated as one.

Fence heights are set by Chapter 16.24 of the municipal code.

• Between the street setback line and the lot line: 4 feet. Support posts or columns may reach 5 feet, and a pedestrian gate or trellis used as an entryway feature may reach 8 feet, within 3 feet of depth and 5 feet of width (§16.24.020(a)).
• Beyond the setback line, front yards and street side yards: 6 feet (§16.24.020(b)(1)).
• Beyond the setback line, interior side yards and rear yards: 7 feet (§16.24.020(b)(2)).
• Backing onto a frontage road, a railroad right-of-way, an industrial or commercial area, or public property that isn't a street: solid board up to 8 feet (§16.24.050).
• At an intersection: nothing over 3 feet above the adjacent curb grade, inside the triangle formed by the curblines and a line joining points 35 feet from where the projected curblines meet (§16.24.040). This one is worth knowing because no variance can be granted from it (§16.24.090).
• Corner lots whose rear yards join: a 6-foot fence is allowed on the street side yard lot line starting 50 feet from the radius point of the corner — but where a driveway falls in that stretch, nothing may be built within 12 feet of where the driveway meets the property line (§16.24.060).
• Barbed wire is prohibited, as is any wire, twine or rope fence under 3 feet standing within 3 feet of a public sidewalk (§16.24.070).

Properties fronting University Avenue between Middlefield Road and the eastern city limit have their own front-yard allowance with conditions attached, including a driveway sight-distance triangle (§16.24.020(c)) — that rule is specific to those addresses and is not a citywide driveway rule.

Heights come from Chapter 16.64, and the city publishes its own guidance for residents.

• Residential districts: 7 feet in any yard, with two exceptions below.
• Required front setback: 4 feet.
• Corner-lot triangle: 3 feet, inside a triangle measured 35 feet from the point where the two streets intersect, along the right-of-way lines of both, with a line joining those points.
• Wood fences not over 7 feet are exempt from a building permit. Going above the height limits is a use permit under Chapter 16.82; properties fronting Santa Cruz Avenue have a separate procedure (§16.64.030, §16.64.035).
• How height is measured: from finished ground level at the fence, and where the ground differs on the two sides, from the lower of the two. Inside the corner triangle it is measured from the lowest edge of the constructed roadway or shoulder.

Menlo Park's own guidance carries a warning worth repeating: the public right-of-way here often runs past the curb and sidewalk into what looks like your front landscaping, and your neighbours' fences are not a reliable guide to where the line actually is. Repairing in place sidesteps the question. Rebuilding reopens it.

The city sets fence standards through its development permit requirements, and the split between wood and everything else is the one to understand first.

• Single-family, front yard: 3 feet, within the first 20 feet measured from the front property line.
• Single-family, side and rear yards: 6 feet — and up to 7 feet only with a planning permit and written consent from the adjacent neighbours.
• A wood fence 6 feet or under on a single-family lot needs no permit. Any non-wood fence, any retaining wall, and any wood fence over 6 feet needs a building permit. Over 6 feet, or on multifamily, commercial or industrial property, a planning permit is required as well.
• Corner lots: 3 feet inside the 35-foot traffic visibility triangle at the intersection. A street side yard fence may reach 6 feet but has to sit 5 feet back from the side property line and never at the sidewalk edge.
• Where your rear yard meets a neighbour's side yard and a driveway runs alongside it, nothing over 3 feet within the first 10 feet.
• Height is measured from adjacent grade to the top of the fence, including decorative lattice and the posts — a detail that catches people who add lattice to an existing 6-foot fence.
• Barbed wire is not permitted. Anything inside an HOA needs the HOA's approval before the city's.

A fence on the boundary is governed by state law, not by the city — California Civil Code §841, the Good Neighbor Fence Act of 2013.

The starting position is that adjoining owners are presumed to share equally in the benefit of a boundary fence and, unless they have agreed otherwise in writing, are presumed equally responsible for the reasonable costs of construction, maintenance or necessary replacement.

The part most people miss is procedural: before incurring those costs, a landowner must give 30 days' prior written notice to each affected adjoining owner. The notice has to describe the problem, the proposed solution, the estimated cost and how it would be shared, and it must tell the neighbour about the presumption of equal responsibility. Doing the work first and presenting the bill afterwards is the common way this goes wrong.

The presumption can be rebutted. A court may order a smaller share, or none, where equal responsibility would be unjust — weighing whether the cost is out of proportion to the benefit that owner actually gets, whether it exceeds the value it adds, whether it imposes real hardship, and whether the project itself is reasonable or reflects one owner's taste rather than a shared need.

In practice this is why a repair is easier to agree on than a replacement: a rotted post is a shared necessity that is hard to argue with, while a taller fence in a different material is a preference somebody has to be talked into.

Do I need a permit to repair my fence? Usually not, in all three cities, as long as the repair leaves the height, the material and the position where they already are. Mountain View is the most explicit: a wood fence 6 feet or under on a single-family lot needs no permit at all. Menlo Park exempts wood fences up to 7 feet from a building permit. Palo Alto's fence chapter sets height and location rules rather than a permit process for a standard fence.

How tall can my fence be? It depends on which yard it stands in. In back and side yards: 7 feet in Palo Alto and Menlo Park, 6 feet in Mountain View (7 with a permit and the neighbours' written consent). Along the street it drops sharply — 4 feet in Palo Alto's setback strip and Menlo Park's front setback, and 3 feet in Mountain View's front 20 feet. At corners, all three cut it to 3 feet inside a 35-foot visibility triangle.

My neighbour won't pay half. Now what? The 50/50 split under Civil Code §841 is a presumption, not an automatic bill. Serve the 30-day written notice first — with the problem, the fix, the cost and the split spelled out — because that is what the statute asks for. If they still refuse, the presumption can be rebutted in court on grounds of fairness, so the practical question becomes whether the work is a genuine shared necessity. Mountain View offers free mediation for exactly this dispute through Mountain View Mediation Services.

More than half of my fence is damaged — is it now a rebuild? Not by that fact alone. None of the three cities publishes a percentage threshold that converts a repair into new construction for a fence. What matters is whether the finished fence is taller, in a different material, or in a different place than the one that stood there. A fence can be extensively repaired and still be the same fence, as long as those three things hold.

Rules change, and the version that matters is the one in force at your address on the day. Before any work we check the height limit for the specific yard the fence stands in, whether a corner or driveway triangle touches it, whether the fence sits on the boundary or inside it, and whether anything about the job would change its height, material or position. If it would, we say so before starting, not after.

This page is a description of what we look at, not legal advice. For a decision that turns on your specific lot, the city's planning counter is the authority — Palo Alto, Menlo Park and Mountain View will all answer a fence question directly.

Send photos — the base of the posts, the full run, and anything you have already tried. We'll tell you which side of the line your fence is on, and if a repair isn't worth doing we'll say so.

You can also start from fence repair, or read one Palo Alto fence that failed at the posts and nowhere else. ===END===