The primary objective of this work is to assess the condition of an existed structural steel frame building that is already occupied by users, and to investigate the load bearing capacity of the major structural members (beams, columns) of the steel frames, so that to find out the possibility of added additional new story that can help to increase the capacity of the building. It was decided by the authorities and the building officials to add another story to accommodate an expansion to increase the occupancy capacity of the building. Structural analysis of the building frames due to original loads would be implemented and then additional story would be added, on the other hand a structural analysis would be performed due to additional story (additional loads). Linear static analysis in both cases was done and responses was evaluated by Demand to Capacity Ratios (DCR), And by a comparison the DCR for columns in both cases, it was found that the bearing capacity of columns allow to add new story safely. Furthermore, redesign of the new building would be carried out using commercial software sap2000. The building façade, such as veneers and curtain walls are not considered as structural elements therefore, not covered in this work. (The connections of joints and foundation analysis would be covered in farther considerations using another finite element program).