Do I need a permit for a fence in
Plum, Pennsylvania?

Plum fence permits — the key details

Plum's zoning code ties fence height to both location and material. Non-masonry residential fences (wood, vinyl, chain-link, metal) max out at 6 feet in rear and side yards; masonry fences (brick, stone block, poured concrete) max out at 4 feet unless you obtain a variance. The 6-foot rule is measured from grade at the lowest point of the fence to the top of the fence itself—if your slope runs downhill, that can push you over height in spots, which is why the City of Plum Building Department wants a site plan with elevation data. Front-yard fences, defined as any fence forward of the front-wall buildline or within the front-yard setback, require a permit at any height. This isn't a gray area: Plum enforces it. The reason is sightline protection at street corners and pedestrian safety—Plum has specific sight-triangle requirements for corner lots (typically 25 feet along each street frontage, clear of obstruction above 3.5 feet). If your lot is a corner lot and you're tempted to install a front fence without a permit, know that code enforcement will catch it on the first complaint, and the fine is non-negotiable.

Pool barriers are their own universe. Any fence, wall, or enclosure serving as a barrier to a swimming pool (in-ground or above-ground deeper than 24 inches) requires a permit regardless of height or location. Plum requires four-sided fencing (gate on all four sides or a compliant enclosure) and mandates a self-closing, self-latching gate mechanism meeting IBC Section 3109 standards. The gate must swing away from the pool, latch from the pool side, and be tested by the inspector. A common rejection in Plum: applicants submit site plans with no gate detail or specify a manual handle instead of an automatic closer. The permit fee for a pool barrier is often the same ($50–$200), but the inspection is mandatory and non-negotiable, and corrective work adds cost. If you're installing an above-ground pool and plan a fence around it, get the permit before or during fence installation—installing the pool first and the fence second can trigger separate pool-permit steps in Plum.

Exemptions are narrow. A wood, vinyl, or chain-link fence under 6 feet in a rear or side yard, not serving as a pool barrier, installed by the property owner (homeowner-pull is allowed in Plum for owner-occupied properties), does not require a permit. Replacement of an existing fence with identical material and footprint in the same location does not require a permit, provided it doesn't change height or location—but the Building Department wants proof of the original fence (photos, prior permit, deed reference) and will ask if you've moved the line. If you're replacing a 5-foot wood fence with a new 5-foot wood fence in the exact spot, exempt. If you're replacing it with a 6-foot fence, even if the old fence was 6 feet, it's a new fence and requires a permit. Masonry replacement is trickier—even like-for-like masonry fences sometimes require inspection due to structural concerns, so call the Building Department before assuming exemption.

Plum's site-plan requirement is specific and often trips up DIY applicants. You must submit a property survey or site plan showing: (1) lot dimensions and property lines, (2) the proposed fence location with setback dimensions from the property line (minimum 6 inches in most residential zones, but corner lots have tighter rules), (3) height call-out in feet, (4) material specification, and (5) if it's a pool barrier, gate location and swing direction. Many homeowners bring in a sketch; the Building Department will accept a hand-drawn plan with dimensions, but if your lot is a corner lot or the fence is within 5 feet of a utility easement (common in Plum due to gas and electric lines), you may need a professional survey or at least a utility-locate map. The Building Department has a public GIS portal; you can check easements and setbacks online before you file. Setback violations are the #1 reason for permit rejection in Plum. Even a 2-foot overage toward a neighbor's line will be flagged, and the Department will require you to move or remove the fence. Getting a variance (if you're just slightly over) costs another $500–$1,000 and involves a hearing before the Zoning Hearing Board.

Frost depth in Plum is 36 inches, which affects post-hole depth for structural frost-heave protection. The code doesn't explicitly mandate 36-inch footings for every fence, but the inspector may require them if the fence is in an area prone to frost upheaval (clay soils, low drainage). For a standard wood-post fence, digging 30–36 inches deep with a 6-inch concrete footer is best practice in Plum. Vinyl and chain-link fences, if installed on a pre-engineered system, often use shallower footings; the manufacturer spec will call out depth, and the Building Department will accept that. Masonry fences over 4 feet absolutely require a footing detail (usually 12–18 inches deep, on undisturbed soil) and an inspection before backfill; this is where many DIY homeowners in Plum run into trouble. If you're pouring concrete for a masonry fence, have the Building Department inspect the footing trench before you set the first course. The fee for a footing inspection in Plum is typically rolled into the permit, not charged separately. Once the fence is built, request a final inspection; the inspector walks the property, checks height (brings a tape measure), verifies setbacks, and confirms that gate mechanics work if it's a pool barrier. Final inspection usually happens within 7–10 business days of your request.

Three Plum fence (wood/vinyl/metal/chain-link) scenarios

Plum's corner-lot sight-triangle rule and front-yard fences

Plum enforces a sight-triangle safety zone at street intersections. If your property is a corner lot (two street frontages), any fence, wall, or landscaping over 3.5 feet high within the sight triangle is a violation. The sight triangle is defined as a triangular area with a vertex at the corner of the intersection and extending 25 feet along each street centerline (some municipalities use 20 or 30 feet; Plum typically uses 25). Within that triangle, nothing over 3.5 feet can obstruct a driver's view of pedestrians or cross-traffic. This rule applies even if the fence is on your own property—it's a public-safety rule.

For a corner-lot homeowner wanting a privacy fence, the practical result is that the front sides of the fence (facing the streets) must be 3.5 feet or shorter, or the fence must be set back beyond the sight-triangle boundary. If your fence runs perpendicular to the street (side-yard fence), you measure 25 feet along the street from the corner point; if the fence crosses into that zone, the portion in the zone is capped at 3.5 feet. Most corner-lot fences in Plum are stepped: 3.5 feet along the street-facing sides, then taller (up to 6 feet) on the interior. The Building Department will require a site plan showing the sight-triangle geometry and confirming compliance. If you submit a plan that violates it, the application will be rejected. Getting a variance for the sight triangle is possible but expensive ($500–$1,000 for the hearing) and often denied unless you have specific grounds.

When in doubt, call the Building Department or visit the Plum GIS portal to check if your lot is a corner lot and to measure the sight triangle. A professional surveyor can confirm the boundary and the triangle for $300–$500 if you want certainty. For a corner-lot owner, this is worth doing upfront before you order materials or hire a fence contractor.

Coal-country concerns: easements, utilities, and frost depth in Plum

Plum sits in Allegheny County, a region with a legacy of coal mining and current active natural-gas and electrical infrastructure. Your lot may have recorded easements for gas, electric, water, sewer, or fiber that restrict or prohibit fencing. Before you file a permit application, use the Plum GIS portal or contact the Building Department to check for easements. If a utility easement crosses your property and your proposed fence line intersects it, you'll need written consent from the utility company (usually free but time-consuming) or you'll need to relocate the fence. The Building Department will not issue a permit for a fence built across an active easement without utility sign-off. Additionally, when you dig post holes, call 811 at least three days before you start; the locating service will mark gas, electric, and water lines so you don't rupture them.

Frost depth in Plum is 36 inches, and the soil is primarily glacial till (clay-heavy) with some karst limestone underlying the till. Clay soil is prone to frost heave—the freeze-thaw cycle pushes posts upward seasonally. For a fence to survive multiple winters in Plum without settling or shifting, post footings should extend 30–36 inches below grade with a concrete collar (6–8 inches of concrete above grade helps too). Vinyl and chain-link fence systems, if on a pre-engineered frame, may have shallower footing specs; follow the manufacturer. Masonry fences require a footing inspection before you backfill, specifically because of frost and settlement risk. If you skip the deep footing in Plum, your fence will heave and shift after the first hard winter, and code enforcement may flag it as unsafe.

The limestone underlying Plum can also mean karst features (sinkholes, subsurface voids). If your lot is in a known karst zone (rare but possible), the Building Department may flag it and request a geo-engineer's review. This is more common for large structures, not typical residential fences, but it's worth knowing. The GIS portal or a call to the Building Department will clarify if your lot is in a karst zone.

Common questions