Evolution of BIM
The first generations of CAD represented buildings with geometry—vector based lines, arcs and circles. A CAD drawing was easy to modify and replicate. It also provided greater precision than pencil on paper. But it was dumb: lines drawn with a computer instead of a pencil.
Object CAD: Then “smart” objects with properties were added. Objects like windows, doors, walls, roofs or stairs had properties that governed their behavior. A window could be pulled from a resource file into a drawing and stretched to fit the required opening. As it was stretched, the panes would grow but the jamb section would not. A user could associate information to the object such as the supplier, part numbers, the finish, the warranty and so on. The drawing objects were “smart.” They knew how to behave and what they were.
BIM: From that point, it was a logical step to envision an entire building as a smart object with endless possibilities for algorithms that govern its behavior and and associated information. BIM emerged.