Boulder County, CO Fence Regulations: Material Restrictions (2026)
Key Facts
- Typical fences
- Wood, wire, chain link OK
- Open wire spec
- One strand per foot of height
- Open pipe/rail
- 90% open, posts 8 feet apart
- Masonry
- International Building Code standards
- Floodway limits
- Solid wood/chain link restricted
Summary
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.
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.
Full Breakdown
Boulder County's P/28 does not dictate a materials list for typical residential fences up to 6 feet, so wood, wire, vinyl, and chain link are generally acceptable. Material specifications become mandatory in a 100-year 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; open pipe or rail fencing shall be 90% open with posts no closer than 8 feet apart. Chain link and solid wood are case-by-case or barred in the floodway. Masonry fences must satisfy International Building Code structural design standards. Covenant-imposed material rules, which the county does not enforce, may still apply within subdivisions.
Violations & Fines
Floodplain fences using disallowed materials or spacings can be denied a Floodplain Development Permit or ordered replaced; masonry fences that fail IBC standards require engineered correction.
Frequently Asked Questions
What fence materials are allowed in a floodplain?
Are there material rules for a backyard privacy fence?
Sources & Official References
Other rules in Boulder County
Compare Boulder County to another location·View the Colorado fence regulations overview
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