Upper Darby, PA Fence Regulations: Retaining Walls (2026)

Upper Darby folds its retaining wall rules into the township's fence ordinance, § 550-39, rather than a stand-alone wall chapter. Subsection C(4) sets the permit threshold: a retaining wall under four feet in height needs only a fence permit, the same lighter-weight approval used for an ordinary residential fence, while a retaining wall over four feet requires a full building permit, which brings engineering and construction-code review into play. The distinction matters because a building permit application typically requires stamped plans and inspections that a fence permit does not.

Placement is also regulated where a retaining wall interacts with a fence: § 550-39C(3) bars front yard fences from being located directly above a retaining wall, requiring the fence to be set back at least six inches from the wall's edge, a rule meant to keep a fence-on-wall combination from effectively creating a taller barrier than the height limits in § 550-39C(1) and (2) allow. Property owners building a wall to hold back a graded slope, expand a driveway, or level a rear yard need to measure the finished wall height against the four-foot line before applying, since crossing it changes both the permit type and the review standard applied by the Zoning Officer and the Building Code office.