Fence Installation in Atherton

One request, one contractor. He calls back with what he saw in the photos, what he would confirm on site, and what the Town will want to see before the first post goes in. Scope, estimate, permit and contract are between you and him.

Six feet along the street. Atherton's height table allows fences up to 6 feet along a front lot line or public street, not only on side and rear lines (AMC § 17.46.030, Table 17.46.030-1). Along the Town boundary the limit is 8 feet unless that boundary faces a street; lot lines adjoining a public or private school or the railroad right-of-way also allow 8 feet. At a street intersection it drops to 3 feet inside the clear visibility triangle — 30 feet from the corner measured along the curb, gutter or edge of pavement (§ 17.60.020). A fence over 6 feet must be screened from public view by planting that reaches full height within three years (§ 17.46.030).

Seven streets use a special height measurement. Along El Camino Real, Marsh Road, Middlefield Road, Valparaiso Avenue, Alameda de las Pulgas, Bay Road and Ringwood Avenue, the fence or wall may be 6 feet above natural grade or 8 feet above the elevation of the adjacent pavement centerline, whichever is higher (Table 17.46.030-1, note 2). On a lot that sits below the road, this formula can materially change the permitted top elevation of the fence.

Permits. A zoning clearance is required for fences, walls, entry gates and posts unless an exemption applies (§ 17.46.020). The Town's guidelines require a building permit for a fence within 10 feet of a public right-of-way and for a fence over 6 feet (General Guidelines for Fences, Walls and Gates, rev. December 8, 2022). For walls, gates, gate posts and columns the same guidelines list the plan submittal — a site plan, elevations and, for any structure over 6 feet, structural calculations — and require a building permit before construction. A fence at least 10 feet from the right-of-way and no taller than 6 feet is the case where the Town's own exemption applies (§ 17.46.020(C)); the contractor confirms which case the lot falls into.

Columns and entry posts are regulated with the fence. Posts and columns incorporated into a fence or wall may not exceed 33 percent of their built height in width, and where a wall steps down from column height the transition may run no more than 20 feet (§ 17.46.040). Entry gates and posts may exceed the fence height table but not 10 feet, with a permit. A new fence that includes columns or an entry gate is designed to those limits from the start; see gate repair in Atherton for what the Town requires of the gate itself.

Heritage oaks on the line. Valley, coast live and blue oaks with a trunk circumference of at least 48 inches, measured 54 inches above natural grade, are heritage trees (Heritage Tree Preservation Standards, 2023, § 1.12). The standards set the tree protection zone at 10 times the trunk diameter unless they say otherwise, and for fences they do: 5 times the diameter from wood or metal fences that require a permit, and 6 times from CMU walls (§ 2.2). Building closer takes a Town Arborist exception, by application; where trenching closer than 10 times the trunk diameter is approved, the standards require it to be hand-dug. A fence line that runs under a large oak is laid out around the tree before the first hole.

Replacing an existing fence. Existing location and height do not by themselves answer whether the replacement is permit-exempt. Before rebuilding, the contractor checks the property line, the distance from the public right-of-way, the proposed height and any existing permit record. For a fence on a shared property line, see who pays for a shared fence in California.

Full height and setback details are on the Atherton fence rules page. For what fails on an existing fence and when repair is enough, see fence repair.

• Photograph the run from each end, and the street edge or neighbor line it follows — three photos.
• Photograph any oak within the fence line.
• Say whether the lot is on a corner and whether it fronts one of the seven regulated streets.
• Say whether the new fence replaces an existing one, and whether that one sits on a shared property line.

Yes. The height table allows 6 feet along a front lot line or public street (AMC § 17.46.030), with 3 feet inside the clear visibility triangle at a corner and the special measurement on the seven regulated streets.

A zoning clearance applies unless an exemption does (§ 17.46.020). The Town's guidelines require a building permit for a fence within 10 feet of a public right-of-way or over 6 feet. A fence set back at least 10 feet and no taller than 6 feet is the Town's exempt case; the contractor confirms which applies to the lot.

6 feet above natural grade or 8 feet above the elevation of the adjacent pavement centerline, whichever is higher (Table 17.46.030-1, note 2). The contractor measures the grade difference on site.

Yes, subject to the Town's permit requirements and § 17.46.040: columns no wider than 33 percent of their built height, transitions no longer than 20 feet, entry posts no taller than 10 feet with a permit.