There are three methods to figure out wind loads for structure by wind loads
1. Simplified Procedure ( height < 30 ft, Slope < 10 degrees)
2. Analytic Procedure
This includes Main Wind Force Resisting System ( MWFRS) in which the wind loads are applied to structure from more than one direction while on Component & Cladding, wind load is being applied to cladding and then transferred to structural components
3. Wind Tunnel
This method is useful to analyze complex conditions, such as Y, L or T shaped non symmetric structures or where the wind loads are heavy and accurate dynamic analysis is required. The scaled models of structures are applied with wind loads thru wind tunnel and dynamic analysis is performed using test results.
(the above article is based on ASCE-05 code and are interpreted per best of author's knowledge, any suggestions or corrections are greatly appreciated.)
Kaushal Kansara, P.E.