Fence Regulations in Seattle, WA

If you live in Seattle or are thinking about moving there, fence regulations are one of those things you probably won't think about until they affect you directly. Seattle has 3 specific rules on the books covering different aspects of fence regulations, and some of them might surprise you.

Height Limits

In Seattle's Neighborhood Commercial and Commercial zones, SMC 23.47A.014.G.5 caps fences and freestanding walls inside a required setback at 6 feet, averaged over sloping grade in 6-foot segments but never exceeding 8 feet at any point. Retaining walls and bulkheads used to raise grade top out at 6 feet, and stacking a fence on a new bulkhead limits the combined height to 9.5 feet.

Key details: Max fence height in setback: 6 ft (8 ft absolute max on slope). Bulkhead/retaining wall height: 6 ft above existing grade. Guardrail on pre-1994 bulkhead: Up to 42 inches. Fence-on-new-bulkhead combined max: 9.5 feet total. Fence setback from cut-protection bulkhead: At least 3 feet.

Building a setback fence, wall or bulkhead beyond these limits is a violation of Title 23 under SMC 23.90.002, and SDCI's Director enforces the Land Use Code under SMC 23.90.004: investigating complaints, issuing a notice of violation, and setting a compliance deadline under SMC 23.90.006. Most fence violations require correction rather than a fine, but SMC 23.90.020 allows an alternative criminal penalty of up to $5,000 per occurrence for willful, intentional or bad-faith noncompliance, charged as a gross misdemeanor for repeat offenders within seven years.

Material Restrictions

Seattle prohibits placing or keeping a barbed wire or electric fence along the margin of any public place, the line where private property meets a street, alley, or sidewalk, if it could hazard a pedestrian. SMC 15.48.020 targets the fence's location and danger to foot traffic, not barbed wire generally, and SDOT enforces it as a Title 15 street-use violation.

Key details: Prohibited materials: Barbed wire, electric fencing. Where it applies: Fence line abutting a public place. Trigger: Hazardous to a pedestrian. Enforcing agency: Seattle Dept. of Transportation (SDOT). Max civil penalty: $500 per day, SMC 15.90.018.

Placing or maintaining a barbed wire or electric fence along a property's margin with a Seattle street, alley, or sidewalk in a way that could injure a pedestrian violates SMC 15.48.020. SDOT can cite the property owner under Chapter 15.91, and Title 15's general civil penalty in SMC 15.90.018(A) allows a cumulative fine of up to $500 per day the hazard remains unaddressed, on top of the misdemeanor alternative in SMC 15.90.020.

Fence Permit Requirements

Most residential fences in Seattle do not require a building permit. Fences 8 feet or shorter without masonry or concrete above 6 feet are exempt. Fences in flood-prone areas, shoreline zones, or environmentally critical areas may need additional review.

Key details: Permit Exempt: 8 feet or shorter, non-masonry above 6 ft. Residential Max: 6 ft side/rear, 4 ft front. Flood Zones: Additional review required. Retaining Walls: Permit required over 4 feet.

Fences exceeding height limits: Notice of Violation from SDCI. Fences in restricted areas without approval: required removal or modification.

Seattle is more permissive than most cities when it comes to fence permit requirements. That said, there are still limits.

The Bottom Line

Seattle's fence regulations rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Seattle is broadly strict or permissive.

All of the above reflects Seattle's municipal code as of our last review. If you need specifics on fines, exemptions, or filing requirements, the detailed ordinance pages linked above have the full breakdown.