BIM and CAD
Once upon a time, the earliest architects used sticks to draw diagrams in the sand that represented what they wished their workers to build. Over time, stick lines in the sand begot painted lines on stones, which in turn begot inked lines on paper. This turned out to be the dominant form of design communication for centuries. As computers became smaller and more affordable to businesses, their inherent accuracy and data portability was leveraged to develop the earliest Computer Aided Drafting (CAD) programs. These programs were mere automations of the traditional two-dimensional drafting methods: lines and arcs and patterns were drawn on a flat medium to symbolically represent building components.
Despite existing almost from the beginning of CAD, it is only recently — since the turn of the millennium — that three-dimensional Building Information Modelling (BIM) programs have risen in prominence. Unlike the conceptual 2D representations in CAD, or even the conceputal 3D representations in early modelling and rendering programs, the 3D representations in BIM are not conceptual but as realistic as possible. While the work may still appear to be two parallel lines on the computer screen, in BIM those lines are “known” to be a wall with specific construction properties (layers of materials, fire-resistance ratings, height limitations, and so forth). For the first time in history, architects have the chance to (virtually) build a building before it is physically constructed. The data contained in a BIM file can be shared with contractors, schedulers, building operators, and even maintenance staff.
BIM is the future of the architecture and construction industry. Those who “get it” will survive and prosper; those who don‘t will fade away and be forgotten. BIM is not like CAD. A cogent argument exists debating the merit of drafting on a computer versus drafting by hand. The only analog to the digital BIM file is the building itself.
I am a BIM believer.