Light-Weight Structures (LWS), could be defined as prefabricated and flexible structures with minimum assemblage time in the determined project site. “Room no-3” is a single product designed and engineered with steel frames structure, sandwich panel exterior finishing and dry wall in the interior, which could be used as single unit or rather combination of several pieces. “Room no-3” is a flexible structure in terms of its program and function, instantiating; it could function as a classroom, gym, office, residential space and so on.