7 county-level rules, plus city-specific rules for 2 cities in Larimer County, Colorado.
Verified from official government sources
In unincorporated Larimer County you can build a residential fence up to 7 feet high without a building permit. A permit is required once a fence is over 7 feet AND has a solid, wind-blocking surface; prescriptive fences top out at 9 feet.
Larimer County Residential Fence Permits handout (updated Feb 2026)
When is a building permit required for a fence? When the fence is over 7' high, AND when the fence has a solid surface which wind cannot penetrate (wood, masonry, vinyl, chain link with solid slats, etc).
A residential building permit is required for a fence that is over 7 feet high and has a solid, wind-blocking surface. You submit a permit application, a site plan, and an elevation view; the county inspects footings and the finished fence.
Larimer County Residential Fence Permits handout (updated Feb 2026)
What inspections are required? Setback/footings – after holes are dug and prior to pouring concrete. Framing/final – after the fence is constructed and all framing is visible.
Larimer County's Land Use Code sets no requirement that you get a neighbor's consent to build a boundary fence, and it does not mandate shared-cost agreements. Fence location, cost-sharing, and boundary disputes are civil matters between property owners under Colorado law.
In unincorporated Larimer County, a retaining wall over four feet high is treated as a special structural item that requires engineered detail sections as part of a building permit submittal. Walls in a floodplain or right-of-way get added Engineering review.
Larimer County Building Division, Detached Structures submittal checklist
Detail Sections of critical construction or special structural items like decks, porches, retaining walls over four feet, etc.
For permitted fences built without custom engineering, Larimer County sets prescriptive construction standards: 6x6 support posts at a maximum 6 feet on center and at least 3 feet deep, 2x6 horizontal rails at a maximum 24 inches on center, and a maximum 9-foot height.
Larimer County Residential Fence Permits handout (updated Feb 2026)
Without engineering, the following prescriptive rules apply: 6x6 support posts at 6 feet maximum on center, minimum 3 feet deep (use preservative-treated or decay-resistant wood); 2x6 horizontal support rails at 24 inches maximum on center; Maximum 9-foot fence height.
Larimer County requires noncombustible or ignition-resistant fence materials near structures in wildfire-regulated areas: fencing within 8 feet of a Wildfire Resiliency Code structure, or up to the property line if it is closer than 8 feet, must be noncombustible or ignition-resistant.
Larimer County Residential Fence Permits handout (updated Feb 2026)
Fencing within 8 feet of a structure regulated by the Wildfire Resiliency Code or up to the property line when the property line is less than 8 feet away from the structure shall be constructed with noncombustible or ignition-resistant materials.
Common fence materials — wood, masonry, vinyl, and chain link — are all allowed in unincorporated Larimer County. Solid, wind-blocking materials over 7 feet trigger a permit, and prescriptive wood fences use preservative-treated or decay-resistant lumber.
Larimer County Residential Fence Permits handout (updated Feb 2026)
6x6 support posts at 6 feet maximum on center, minimum 3 feet deep (use preservative-treated or decay-resistant wood); 2x6 horizontal support rails at 24 inches maximum on center; Maximum 9-foot fence height.
2 cities in Larimer County have their own fence regulations rules. Each link goes to that city's dedicated page with code citations.
See every category we cover for Larimer County — parking, noise, fences, fires, animals, pools, and more.
Larimer County Ordinance Hub →