District of Columbia, DC Fence Regulations: Retaining Walls (2026)

DC follows the 2015 International Residential Code with District amendments (published as 2017 DC Construction Codes) for retaining wall regulation. Walls up to 4 feet tall measured from the bottom of the footing to the top of the wall, and not supporting a surcharge, are permit-exempt under IRC R105.2. Walls over 4 feet, walls retaining any soil below a structure, driveway, or sloping ground above the wall, and walls within the setback abutting a public right-of-way require a DOB building permit with engineered drawings. Plans must address lateral earth pressure, drainage (weep holes or drain tile behind the wall), frost depth (footings below 24 inches), and any adjacent foundation impacts. Retaining walls that are part of a regulated historic property or within a historic district need Historic Preservation Review Board concurrence. DC's clay soils and steep topography in wards like Mount Pleasant, Anacostia, and Glover Park make retaining wall failure a recurring neighbor-dispute issue. When a retaining wall sits on a property line, DC applies common-law rules — the owner whose soil is retained bears maintenance responsibility, but a wall built by mutual agreement is shared.