Howard County, MD Fence Regulations: Retaining Walls (2026)

2. Any wall taller than that 3-foot threshold falls outside the exemption and needs a full permit application. 3 requires that application to name the owner, the owner's agent, lessee, or the registered design professional performing the work, plus their addresses, and if the applicant is a business entity, the names and addresses of the people who manage it. 1 lets the Building Official require submitted plans, typically two sets of scaled construction documents showing plans, four elevations and cross sections, and either four copies of a plot plan or one copy of an approved site development plan when the Howard County Subdivision Regulations call for one; for a minor wall the Building Official may waive that documentation and instead accept plot plans alone.

The exemption does not apply to structures in the floodplain, so even a low retaining wall on floodplain property can trigger the permit requirement. Once the wall requires a permit, the Department of Inspections, Licenses and Permits reviews and issues it, and the Building Official may periodically inspect the completed work. 1.