Pre - Engineered building (PEB) is a new concept for the construction of single storey industrial building. The concept is versatile not only due to its quality pre - designing and prefabrication but also due to its time efficiency and light weight. The concept of Pre - Engineered Building includes the technique of providing the best possible section according to the optimum requirements. This concept has many advantages over Conventional Steel Structure (CSB). And Pre - Engineered Building is efficient alternative to Conventional Steel Building. In this paper main frame of Pre - Engineered Structure of 12 m,14m,16m,18m,20m width & 6m Eave height have been analysed and designed by Staadpro to understand behaviour of PEB. The design is done ...