Flood vents under an elevated Outer Banks deck

The deck itself rarely forces the question — the skirting does. The moment you enclose the space beneath an elevated deck below the regulatory flood protection elevation, you have created an enclosed area the floodplain rules treat seriously, and those rules have a specific, inexpensive, routinely botched answer: flood vents, installed and kept unblocked.

The details

The rule and the reason in one breath. Flood vents required below RFPE: flood vents in enclosed areas below the Regulatory Flood Protection Elevation must be installed and kept unblocked to equalize the hydrostatic pressure of rising floodwater — and Dare County notes they are an inexpensive way to decrease flood insurance. That is the whole mechanism: water rising outside a sealed enclosure pushes on the walls with the full height of the flood; the same water rising through open vents pushes from both sides at once and the enclosure survives. The vent is not a hole; it is pressure equalization.

The zone decides how much it matters. VE zone wave-velocity definition: VE zones are the coastal flood zones subject to velocity flooding in addition to still-water flooding — typically along shorelines where wave-action risk is present — and they are the governing zone for oceanfront decks where wave loads are part of the design conversation. In the zones where water arrives with force, the enclosed space under a deck is the space the rules watch hardest, and the vent requirement is the difference between a compliant enclosure and an expensive one.

Kept unblocked is the part that fails, and it fails gently: the lattice gets backed with a storage wall, the kayaks get stacked against the openings, the sand drifts over the bottom row. Hydrostatic equalization requires actual paths for actual water, and an inspection reads the enclosure as it stands, not as it was drawn. If the space under the deck is going to store anything, the vents need to be planned as permanent geometry, not as gaps the gear will respect in its spare time.

And size the project honestly before it starts, because skirting an elevated deck on a coastal lot can quietly become a real construction project. If the enclosure work grows to the G.S. 87-1 — $40,000 threshold — $40,000 or more of undertaking — a licensed general contractor is required, and Dare County's guidance is explicit that NC licensed GC required at $40,000+. A waterfront lot can also carry the CAMA layer, with its minor development permit at the published CAMA minor permit fee $119 (July 1, 2025). The vent is the cheap part; the scope around it is what decides who may build it and which permits it needs.

Enclosing below the deck? Put the vents in the plan, keep the openings honest forever, and check the scope against the licensing line before the lattice goes up — the vent is a small detail with outsized consequences, and it deserves both of those facts at once.