8 min read · Updated 2026-03-22
Wind & Snow Loads — What They Mean for Your Steel Building
Plain-English explanation of how wind and snow loads drive steel building design, price, and safety.
Key takeaways
- ▸Wind loads are set by ZIP code and typically range 90–170 mph design wind speed.
- ▸Snow loads range from 5 psf (Gulf coast) to 100+ psf (mountain regions).
- ▸Under-engineered buildings fail in the first major storm — always meet code.
- ▸A 15% load upgrade typically adds only 4–6% to shell cost.
How wind loads work
The design wind speed for your ZIP code is set by ASCE 7 and the local building code. A coastal Florida site might see 170 mph design speed while central Kansas sees 115 mph. This drives the gauge of the primary frame and the anchor bolt spec.
How snow loads work
Ground snow load (psf) for your county is set by ASCE 7 and modified for roof slope, exposure, and heat loss. Mountain and northern-tier sites can exceed 100 psf and drive substantially heavier trusses.
Why over-engineering is worth it
Bumping wind load from 120 mph to 140 mph typically adds 4–6% to shell cost and dramatically improves survival in a design-level storm event. On commercial buildings, the insurance savings often pay for it in the first two years.