Fence Regulations in Boulder County, CO (2026)
5 county-level rules, plus city-specific rules for 2 cities in Boulder County, Colorado.
Verified from official government sources
Height Limits
Boulder County fences must sit entirely on the owner's property, stay out of the road right-of-way, and not interfere with the sight triangle at intersections. Floodplain fences need a Floodplain Development Permit and specific open-fence designs.
General Fence Construction Requirements
Some RestrictionsBoulder County Land Use Dept. Publication P/28, Fence Requirements
Fences of any height can not interfere with the sight triangle at intersections. The sight triangle varies based on the posted speed of the road.
Fence Permit Requirements
A building permit is required to build a fence over 6 feet high in unincorporated Boulder County, and for a fence of any height inside a 100-year floodplain. Over-6-foot fences must meet zoning setbacks and may need engineered footing plans.
When a Fence Permit Is Required
Some RestrictionsBoulder County Land Use Dept. Publication P/28, Fence Requirements
Fences over 6 feet in height require a building permit for construction, and must meet setback requirements for the zoning district in which they are located. Fences over 6 feet may require plans for the footings and foundation that are prepared and stamped by a professional engineer.
Neighbor Fence Rules
Boulder County requires all fence components, including footings, to sit on the fence owner's own property, and bans fences from the road right-of-way. The county does not enforce private boundary disputes or subdivision covenants between neighbors.
Fences, Property Lines, and Neighbors
Some RestrictionsBoulder County Land Use Dept. Publication P/28, Fence Requirements
All fence components, including footings, must be on the fence owner's property. Fences are not allowed within the road right-of-way.
Retaining Walls
In unincorporated Boulder County a retaining wall over 48 inches (4 feet), measured from bottom of footing to top, requires a building permit. Retaining walls are not counted as fences and must meet International Building Code structural design standards.
Retaining Wall Rules and Permits
Some RestrictionsBoulder County Land Use Dept. Publication P/28, Fence Requirements
The term fence does not include retaining walls. Also, fences built around a developed use... must meet other zoning, land use, and Building Code standards. Retaining walls and masonry fences must meet the structural design standards of the International Building Code.
Material Restrictions
Standard fences in unincorporated Boulder County have no county-mandated material palette, but floodplain and masonry fences do. Floodplain fences must follow open-design specs; masonry fences and retaining walls must meet International Building Code standards.
Approved Fence Materials in Boulder County
Some RestrictionsBoulder County Land Use Dept. Publication P/28, Standards for Fencing in a Floodplain
Open barbed or barbless wire fencing shall have no more than one horizontal strand per foot of height and no more than one vertical wire or post every six feet.
Fence Regulations by City in Boulder County
2 cities in Boulder County have their own fence regulations rules. Each link goes to that city's dedicated page with code citations.
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