Roanoke, VA Environmental Rules: Flood Elevation Requirements (2026)

The rule sits in Roanoke City Code Sec. 36.2-333, the Floodplain Overlay District (F), which applies to every special flood hazard area on the FEMA flood insurance rate map. Under subsection (e)(3)(A), a new residential building or a substantial improvement in Zones A1-30, AE, AH and A with detailed base flood elevations must have its lowest floor elevated to or above the base flood level plus 24 inches. The definition of lowest floor counts a basement, so a basement slab cannot sit below that line. Mechanical systems follow a separate 2-foot rule: electrical, heating, ventilation, plumbing and air conditioning equipment, including ductwork, must be elevated or floodproofed to 2 feet above the base flood elevation.

Subsection (e)(3)(B) applies the same 24 inches to commercial, industrial and other non-residential buildings, with one alternative. In AE, AH and A1-30 zones a non-residential building can be dry floodproofed instead of elevated, but only if everything below the freeboard line is watertight, and a registered professional engineer or architect must certify it. Detached garages, small pole barns, storage sheds, gazebos and picnic shelters can be wet floodproofed.

AO zones, which are shallow flooding areas, work differently. The lowest floor must be 2 feet above the flood depth printed on the map, measured from the highest adjacent grade. Where the map prints no depth, the floor must be at least 4 feet above the highest adjacent grade. In unnumbered A Zones, the applicant must determine the base flood elevation from federal or state data or an engineer's analysis, and the same 24 inches applies.

Paperwork drives the process. Every zoning permit application for a structure needs a FEMA elevation certificate from a licensed surveyor or engineer, and a final as-built elevation certificate is due before a Certificate of Occupancy issues. Enclosed space below the required elevation cannot be habitable and is limited to parking, building access and limited storage. It needs at least two openings on different sides, with 1 square inch of net opening for each square foot of enclosed area, and the bottom of each opening no more than 1 foot above grade. Existing buildings must comply when a repair or improvement costs 50 percent or more of market value over 5 years.