Which statement best describes wind effects around a building?

• A. Pressure is the same on windward and leeward sides
• B. The windward side has lower pressure than the leeward
• C. The windward side has higher pressure and the leeward side lower pressure
• D. The pressure is negligible for design

Answer: (C)

When wind meets a building, it can’t pass through, so it slows to a stop at the windward surface, creating a stagnation pressure that is higher than the surrounding air. As the flow tries to move around and over the building, it tends to separate and accelerate on the leeward side, pulling the pressure down below ambient. This creates a high-pressure region on the windward face and a lower-pressure (suction) region on the leeward side. These pressure differences are what drive the wind loads on the structure. So the best description is that the windward side has higher pressure and the leeward side lower pressure. The other statements ignore, reverse, or deny these pressure differences, which isn’t how wind interacts with buildings.