King County, WA Fence Regulations: Pool Barriers (2026)

King County enforces pool and spa barrier standards through the adopted 2021 International Residential Code Appendix G and the Washington State Building Code under KCC Title 16. Any private swimming pool, spa, or hot tub containing water more than 24 inches deep must be completely enclosed by a barrier at least 48 inches tall, measured from the outside grade. The barrier must have no openings that would allow passage of a 4-inch sphere, and horizontal members on the outside of the fence must be at least 45 inches apart to prevent climbing. All gates must open outward away from the pool and be self-closing and self-latching, with latch release mechanisms at least 54 inches above grade. Where a house wall serves as part of the barrier, all doors leading to the pool must have alarms or the pool itself must have a motorized safety cover meeting ASTM F1346. Hot tubs and spas with locking, code-compliant safety covers are exempt from the barrier rule. Barriers are inspected at final building permit inspection. Washington State drowning prevention rules are strictly enforced because backyard pool incidents are a leading cause of child injury.