From Moonport: A History of Apollo Launch Facilities and Operations
http://www.hq.nasa.gov/office/pao/History/SP-4204/ch11-4.html<br />"<font color="yellow">One of the biggest design problems involved the high windloads that the building would have to withstand. After consulting authorities on wind velocity, URSAM designed the VAB for winds of 200 kilometers per hour. The design had to minimize the building's sidesway, because the work platforms in the high bays were tied into the structure. If the building swayed in high winds, the resulting movement of the platforms might damage a space vehicle. Although the box shape was not the most effective in shedding wind, it kept the sidesway low. The final design held the building's sway to less than 15 centimeters in winds up to 100 kilometers per hour. In higher winds the platforms would be withdrawn from the vehicle.</font> <br /><br />However, we did see the exterior panel damage during Hurricane Frances. The damage was repairable and the shuttles were not damaged, so I'd think the VAB could weather all but the most severe direct hit. It would probably be hard to make it absolutely bulletproof.<br />KW