Montgomery County, VA Environmental Rules: Flood Elevation Requirements (2026)

3 sets the county's one-foot freeboard standard above whatever base flood elevation applies to the parcel, for both residential structures, including manufactured homes, and nonresidential buildings. Nonresidential buildings in A1-30, AE and AH zones get an alternative: full floodproofing to base flood elevation plus one foot, with every wall below that line watertight and able to resist hydrostatic and hydrodynamic loads, certified by a registered professional engineer or architect. Elevated buildings with enclosed space below the flood protection elevation cannot be used for human habitation, only parking, building access or limited storage, and must carry flood vents sized at one square inch of opening per square foot of enclosed area, with the lowest opening no higher than one foot above grade.

Manufactured homes need a permanent foundation on reinforced piers at least thirty-six inches above grade, anchored per the Virginia Uniform Statewide Building Code, plus their own elevation certificate. Recreational vehicles are exempt only if they stay under one hundred eighty consecutive days, remain licensed and wheel-ready, or otherwise meet the full manufactured-home standard. All required elevation data must be recorded on a certificate completed by a licensed surveyor, engineer or architect and filed with the circuit court clerk before the county will issue an occupancy certificate.