Boulder, CO Fence Regulations: Neighbor Fence Rules (2026)

Section 9-9-15(c) of the Land Use Code sets a general seven-foot height ceiling for any fence, wall or hedge, or combination of the three, located within three feet of each other on the same property. Height is measured from the finished grade directly beneath the structure to its tallest point, and a fence built on a berm or mound has the berm's height added to the total. The city manager will not accept an artificially altered grade as a way to beat the limit: if there is evidence the grade was raised or lowered to change the measured height, the manager can reconstruct the original grade and apply the height that would have resulted without the change.

For fences that sit on or within three feet of a shared property line, subsection (c)(2)(B) lets the abutting owners agree in writing to a taller fence, up to twelve feet, provided the fence still measures no more than seven feet when checked from the higher of the two grades within three feet of either side of the line. Without that joint agreement, the standard seven-foot cap controls. Separate exceptions apply to specific situations: a guard fence up to forty-two inches on a retaining wall is exempt from the combined-height rule, athletic-facility fencing such as tennis-court enclosures can reach ten feet if the top portion is at least half open, and the city manager can approve a taller noise barrier along a major street listed in Appendix A. Barbed wire and electric fencing are barred outright except for specific agricultural uses in the A, RR, RE and RL districts, and even then require a fence permit and Underwriters Laboratories-approved controllers.

Variance requests or interpretation disputes go to the city manager under Section 9-2-3, and the manager's decisions can be appealed to the Board of Zoning Adjustment and Building Appeals.