Boulder County, CO Swimming Pools & Spas: Fencing & Safety Requirements (2026)
Key Facts
- Barrier code
- 2021 ISPSC Section 305
- Minimum height
- 48 inches above grade
- Opening limit
- No 4-inch sphere passage
- Gate
- Self-closing, self-latching
- Mesh gap
- Max 1 inch above grade
Summary
A pool, spa, or hot tub in unincorporated Boulder County must be enclosed by a barrier meeting 2021 ISPSC Section 305. The barrier must be at least 48 inches high measured from the outside, with no gaps a 4-inch sphere can pass, and any gate must be self-closing and self-latching.
The top of the barrier shall be not less than 48 inches (1219 mm) above grade where measured on the side of the barrier that faces away from the pool or spa, and such height shall exist around the entire perimeter of the barrier.
Full Breakdown
Boulder County adopts the 2021 International Swimming Pool and Spa Code, whose Section 305 governs residential barriers. A barrier is "A permanent fence, wall, building wall, or combination thereof that completely surrounds the pool or spa and obstructs the access to the pool or spa." The top of the barrier must be at least 48 inches above grade measured on the side facing away from the pool. Openings must not allow passage of a 4-inch sphere, and mesh fencing must sit no more than 1 inch above grade. Pedestrian gates must open outward, be self-closing and self-latching with the latch placed to prevent a child reaching it.
Violations & Fines
An unbarriered or non-compliant pool fails inspection and cannot pass final; existing unenclosed pools are treated as an imminent drowning hazard subject to enforcement.
Frequently Asked Questions
How tall must my pool fence be?
Can my house wall count as the barrier?
Sources & Official References
Other rules in Boulder County
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