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

In the unincorporated County, spas and hot tubs are permitted and inspected through the same Pool or Spa Permit process as swimming pools, administered by the Planning and Building Department under Title 10, which adopts the California Building Standards Codes and the Uniform Swimming Pool-Spa and Hot Tub Code. Applicants submit plot plans and construction, plumbing, mechanical and electrical details and pay the applicable fees. For drowning prevention, the California Swimming Pool Safety Act (HSC 115920-115929) treats a 'spa' alongside swimming pools. A key practical difference is that an approved safety pool/spa cover meeting the ASTM F1346 standard is one of the seven recognized drowning-prevention features under HSC 115922, and a labeled, manually- or power-operated safety cover is commonly used to satisfy the requirements for a spa or hot tub in lieu of a full 60-inch enclosure. Even so, a permitted spa generally must provide at least two of the seven approved features unless it qualifies as exempt, so owners should confirm the exact combination with Planning and Building at plan check. Electrical bonding/grounding and GFCI protection for spa equipment are reviewed under the adopted electrical code, and anti-entrapment suction-outlet protection under HSC 115928 applies to spa circulation systems.