Durham, NC Fence Regulations: Retaining Walls (2026)

UDO Sec. 4 addresses retaining walls as a distinct category from fences and decorative walls. Unlike fences, which are generally excluded from required yards, retaining walls are expressly permitted to be located within required yards, recognizing that grade support is often a structural necessity tied to where a slope actually occurs on the lot. The section then adds one specific setback trigger: where a retaining wall is built to support a grade that is eight feet or more higher than the grade at the interior edge of a project boundary buffer, the wall must also be set back 10 feet from that buffer.

That protects the buffer's plantings and screening function from being undermined by a tall retained-grade condition right at its edge. For development in a Design district, Sec. 5 layers on an additional standard: retaining walls over four feet high must be terraced when located along the street frontage or within the street yard, so a single tall vertical wall facing the street isn't permitted in those districts, it has to step down in stages. That terracing rule doesn't apply outside Design districts. Because the UDO is a joint City-County ordinance, both the yard-placement allowance and the buffer setback trigger in Sec. 4 apply the same way in the City of Durham and in the unincorporated parts of Durham County covered by the same UDO districts.