St. Johns County, FL Fence Regulations: Retaining Walls (2026)

a(4) of the Land Development Code addresses the specific situation where a homeowner combines a retaining wall with a fence on top of or alongside it. Rather than letting the two structures stack to whatever height the general side and rear yard fence rules would separately allow, the code sets a cumulative cap: when the fence is located within five feet of the retaining wall, the combined height of the fence and the wall together cannot exceed eight feet, measured from the base of the retaining wall rather than from the top of the wall or the surrounding grade.

a(3), the rule that would otherwise let a fence built at a higher grade elevation reach only six feet measured from natural grade; the eight-foot cumulative cap controls instead whenever the five-foot proximity condition is met. The practical effect is that a homeowner grading a sloped side or rear yard with a retaining wall needs to measure fence height from the wall's base, not just from the top of the wall, before adding fencing on or near it. Because the Land Development Code addresses retaining wall height in this fence-combination context rather than through a freestanding structural or building-permit standard here, homeowners planning a retaining wall as part of a larger drainage or grading project should also confirm with Growth Management's Building Services whether a Development Permit or engineering review applies to the wall itself, separate from this height limit governing it once a fence is added.