Pre Engineered Buildings (PEB) are steel structures which are prefabricated and build in a very short period of time.PEB has its origin in the 1960s, but these are widely in practice in almost all parts of the world during recent years. Construction of steel buildings and the steel industries are rapidly growing in India as well as other parts of the world. For the construction of the industrial shed, residential buildings and commercial complex, Conventional steel building concept are commonly in practice. PEB concept is also simple and can be easily adopted and used extensively for the construction of Industrial, Residential and Commercial Buildings. The adoptability of PEB in the place of CSB design concept resulted in many advantages, including light weight structures, economical and easier fabrication process. For the construction of CSB, hot rolled sections are used which have uniform cross-section throughout the length, whereas in the construction of PEB steel sections, which are tailored and profiled based on the required loading effects are used. The concept includes the technique of providing the best possible section according to the optimum requirement. Due to lack of awareness and confidence in the design and execution of PEB buildings, still, it is not the first choice of owner and designer in India. The present work involves the comparative study of PEB and CSB Concept for a multi-story building. This is achieved by analyzing and designing G+4, G+2 and G+1 commercial building with length 140m, width 40m, eave height 18m,12m, and 9m respectively R slope 1/10 using STADD PRO and IS 800-2007 Design code, by both concepts.