Mendocino County, CA Swimming Pools & Spas: Hot Tub Rules (2026)

Mendocino County regulates spas and hot tubs through the same Title 18 building framework and adopted California Residential Code that governs swimming pools. By state standard, an outdoor hot tub or spa must be provided with a safety barrier and inspected before being filled, unless the spa has a locking safety cover that complies with the ASTM International F1346 standard, in which case it is exempt from the pool-barrier and Swimming Pool Safety Act enclosure requirements. A permanently installed (hard-plumbed) spa typically requires a building permit plus plumbing and electrical permits for the equipment, heater, and bonding. Portable, self-contained spas may avoid a building permit but still require proper electrical connection and grounding, and a spa without an ASTM F1346 locking cover must be surrounded by a barrier meeting the 60-inch height and self-latching-gate rules described for pools. As with pools, the County applies the state code rather than a stricter local spa ordinance. Owners should verify electrical bonding and GFCI protection, which the California Electrical Code requires for all spa installations.