Which exposure category applies to open terrain with no significant obstructions?

• A. Exposure C
• B. Exposure B
• C. Exposure D
• D. Exposure A

Answer: (A)

Wind loads are influenced by the surrounding terrain. When there are no significant obstructions, the wind field at the building site is less disturbed and can apply higher pressures to the structure. In this context, the exposure category defined for open terrain with essentially no obstructions is Exposure A. The idea is to capture the least-shielded conditions, which produce the corresponding wind effects the design must resist. The other exposures represent environments with some degree of shielding or special conditions (urban/suburban clutter, open terrain with some obstructions, or coastal/open-water areas), so they do not describe truly open, unobstructed terrain.