St. George, Hurricane, Washington City, Ivins, Santa Clara and LaVerkin: southern Utah's high-desert climate means a much lighter snow load than the Wasatch Front. But the Hurricane Fault runs through the county, so seismic engineering still matters.
St. George's 21 psf snow load is far lighter than Cache Valley's 43 psf or Weber's 37 psf. But Washington County still requires PE-stamped engineering, and the Hurricane Fault (source of the 1992 M5.8 St. George earthquake) means seismic design still applies. Lighter snow doesn't mean lighter code requirements.
| Code criteria (Washington County) | Value | What it means for your build |
|---|---|---|
| Building-permit threshold | 200 sq ft (IRC default) | 200–600 sq ft needs a permit & IRC foundation standards; under 600 sq ft with ≤10 ft eave skips frost protection. |
| Ground snow load | ≈21 psf (St. George, ~2,585 ft) | Lightest in our service area. Higher-elevation areas (Pine Valley, Central) run heavier. |
| Design wind speed | 90 mph | Lighter than the Wasatch Front's canyon-mouth zones, but still engineered per site. |
| Seismic design category | D (confirm per site) | Hurricane Fault, not the Wasatch Fault. Source of the 1992 St. George earthquake (M5.8). |
| Frost / footing depth | ≈12–18″ | Notably shallower than northern Utah's 30″ standard. Confirm exact depth with your city. |
| Adopted codes | 2021 I-codes · 2020 NEC | Statewide since July 1, 2023. |
Figures shown are representative St. George values. Washington County is a Utah Snow Load Study "case study" area. Your engineer determines the exact site value. Verify permit and frost-depth specifics with your city building department.
St. George and most Washington County cities exempt detached accessory buildings up to 200 sq ft from a building permit. Buildings from 200 to 600 sq ft need a permit and must meet IRC foundation standards; buildings up to 600 sq ft with a 10 ft or lower eave height are exempt from frost-protection requirements. A metal garage or shop with a foundation and electrical needs a permit regardless of size.
Washington County's high-desert climate means dramatically lighter snow loads than the rest of Utah. St. George runs about half of Salt Lake County's valley-floor load. But the county sits along the Hurricane Fault, the source of the 1992 magnitude 5.8 St. George earthquake, so seismic design still matters and shouldn't be skipped just because the snow load is light. Frost depth is also notably shallower, roughly 12–18 inches versus 30 inches along the Wasatch Front, which changes your foundation planning.
Over 200 sq ft requires a building permit. Structures from 200–600 sq ft must meet IRC foundation standards; those up to 600 sq ft with a 10 ft or lower eave don't require frost protection.
Yes. St. George runs about 21 psf versus 28–43 psf along the Wasatch Front. Higher-elevation parts of the county still carry a heavier load, so we engineer to your exact address.
Yes. Washington County sits along the Hurricane Fault, which produced the 1992 St. George earthquake. Snow load and seismic design are separate requirements. Light snow doesn't reduce seismic engineering.
Yes. Every building includes PE-stamped engineering prepared for your loads and jurisdiction.
Get instant pricing, then a firm quote with engineering sized to Washington County code.