Which exposure category applies to urban or suburban environments?

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

Answer: (B)

Wind exposure categories describe how surrounding terrain and obstructions affect the wind pressures a building must resist. In urban or suburban environments, dense development—lots of buildings, trees, and other structures—blocks and slows down wind, creating a sheltered setting compared with open land or coastlines. That shielding effect is what defines the category used for city and suburb sites: it accounts for the presence of frequent obstructions that reduce wind speeds. The other categories represent progressively less obstruction—open terrain with few obstacles, or open water along coasts—where winds act on the structure more freely and pressures are higher. So, for urban or suburban environments, the category that captures this shielding by surrounding buildings and vegetation is the appropriate choice.