What requires a permit, what is exempt, and how North Carolina's building code applies to outdoor living projects in Belmont, Cramerton, Mount Holly, and the NC side of Lake Wylie — where Duke Energy controls the shoreline. Reviewed August 2026.
North Carolina's residential code sets the baseline: decks more than 30 inches above grade require a building permit, as do roofed structures, attached work, and pools over 24 inches deep — with the 48-inch barrier and self-latching gate rules attached. NC's 12-foot rule is the quiet exemption: a detached accessory structure with no dimension over 12 feet needs only a zoning permit. Gaston County's building office serves most of the county, with Belmont, Mount Holly, and Gastonia running their own zoning — and on the Lake Wylie waterfront, Duke Energy's shoreline permits add a second rulebook below the water line.
At-grade paver and concrete patios are generally exempt from building permits — zoning setbacks and drainage still apply, and on expansive Piedmont clay, base preparation and water management are what keep hardscape flat. Retaining walls above roughly four feet require engineering and a permit; on Lake Wylie's sloped waterfront lots, the wall is usually the permitted element, not the patio.
Lake Wylie's shoreline is managed by Duke Energy under its federal hydroelectric license, and that authority does not stop at the state line — the same system governs the Gaston County shore as the York County, SC side. Docks, boat lifts, boathouses, and seawalls require a Duke Energy Lake Services permit; the county permits the patio, pergola, or pool above the shoreline. Allscape designs lakefront projects to clear both systems in one coordinated plan.
The short version of the rules for the three most common outdoor living projects. Confirm specifics with Gaston County's building office or your city — requirements are finalized at plan review.
No building permit for at-grade flatwork in most cases. Zoning setbacks and drainage apply. Retaining walls above roughly four feet need engineering and a permit.
Deck over 30 inches: permit required. Detached structure with no dimension over 12 feet: zoning permit only. Roofed, attached, or motorized structures: permitted, engineered work.
Pool over 24 inches deep: county permit plus 48-inch barrier. Dock, lift, or seawall on Lake Wylie: Duke Energy Lake Services permit — the county permits only the electrical connection.
Gaston County including Belmont, Cramerton, Mount Holly, Gastonia, McAdenville, and the Lake Wylie waterfront communities on the North Carolina shore. Duke Energy's shoreline rules apply lake-wide, across both states.
