Plano, TX Fence Regulations: Retaining Walls (2026)

Sec. 6-178 (Fence construction and materials), in Chapter 6, Article VII 'Fences,' sets the retaining-wall threshold inside the same subsection that governs general fence construction: subsection (a) requires any fence to be able to structurally support its materials per the adopted building code, and subsection (b) states 'No permit is required for a person constructing a masonry fence less than twenty-four (24) inches in height or a masonry retaining wall less than forty-eight (48) inches in height. Retaining walls greater in height than forty-eight (48) inches shall be in compliance with a design submitted by a registered engineer.

' Subsection (g) separately requires that fence posts attached to or supported by other structures, including retaining walls, have a foundation and anchorage sufficient to prevent movement of the retaining wall itself. Retaining walls tied to a broader fence project still fall under the general permit rule in Sec. 6-179, which requires a building inspections department permit to construct or alter a fence (with a carve-out when repairs affect 25% or less of the fence area in a 12-month period), and under Sec. 6-181, which requires all fences and fence locations to conform to the zoning ordinance.

Sec. 6-188 adds that no fence, which functionally includes retaining walls used as fence support, may be built within a drainage or floodway easement unless the city engineer first determines in writing that it will not interfere with or impair the natural flow of water across the easement.