Gaithersburg, MD Swimming Pools & Spas: Hot Tub Rules (2026)

Hot tubs and spas in Gaithersburg are regulated under the city's building code and zoning ordinance. An electrical permit is required for the 240-volt dedicated circuit typically needed for hot tub installations. The circuit must include a GFCI disconnect located within line of sight of the spa and at least 5 feet from the water. If the hot tub water depth exceeds 24 inches, barrier fencing requirements apply unless the unit has a locking hard cover meeting ASTM F1346 standards. Hot tubs must be located in rear yards and set back at least 5 feet from property lines in most zoning districts. Structural support is important when placing hot tubs on decks. Decks supporting hot tubs may require engineering review to confirm load-bearing capacity, particularly if the combined weight of water and occupants exceeds 100 pounds per square foot. Hot tubs must not be placed in easements, over septic systems, or within required fire access areas. Drainage from hot tubs should not discharge onto neighboring properties. Water discharge must not enter storm drains, consistent with WSSC and MS4 stormwater requirements. Contact the Building Division at (301) 258-6330 for permits.