From CAD to BIM: Part I - History of CAD

A brief history of CAD to understand the path that led to BIM
Català - Castellano - Deutsch
I mentioned on a previous post my intention to go into BIM and IPD. Unfortunately for now, I have not the luck to be working on a daily basis with either, so my initial approach here will be more theoretical. I am trying to build the basis of what my Master Thesis is going to be, so forgive me if sometimes things sound a bit basic or repetitive.

BIM, as I see it, is still Computer Aided Design, but it allows you to add an “n” number of dimensions (like costs, scheduling, etc), and strongly modifies the work process to design, build and maintain a building. But since it is in my point of view an evolution of CAD, I think it is important to start with brief history of CAD.

In 1957, Dr. Patrick J. Hanratty had developed the first commercial CAM (Computer Aided Machining) program. It was a numerical control (NC) machining software developed in Pronto , the first NC commercial programming language. Hanratty is regarded as the father of CAD / CAM since these two branches became slowly one.

The first CAD software with a graphical interface was Sketchpad, developed in 1963 by Ivan Sutherland. Sketchpad was a Program in which the user could graphically interact with the program through a screen, a light pen used to draft, and a set of buttons that allowed the user to enter parameters and constraints. Although it never became commercially available, the ideas on Sutherland´s PhD dissertation became highly influential for future generation CAD developments.


First-generation CAD software systems were 2D drafting applications developed by a manufacturer's internal IT group and primarily intended to automate repetitive drafting tasks. During the 1960s, Hanratty himself developed DAC, a CAD system, while working for General Motors Research. Other companies like Ford (PDGS - 1967), McDonnell-Douglas (CADD - 1966), and many others followed soon after that.

During the 1970s the transformation from 2D to 3D began. The French Aerospace Company, Avions Marcel Dassault, developed CATIA, after purchasing a source code license from Lockheed Martin. CATIA is still nowadays leading software in the Aerospace, Automotive and Shipbuilding Industries. One of the most important research dissertations of the decade was K. Vesprille's (at Syracuse University) 1975 PhD dissertation "Computer-Aided Design Applications of the B-Spline Approximation Form" on Complex 3D Modeling. It is from the end of this decade that one of the first books marketing CAD for architects appeared. “Computer Aided Architectural Design” by William J. Mitchell from 1977 is a hint that CAD was already being marketed to architects. The widespread adoption by architects would take still years.


During the 1980s the CATIA, Pro/Engineer, Unigraphics and I-DEA became the leading CAD software packages. All of them powerful 3D modeling software systems with their core business on the industrial production (for this reason sometimes referred as CAE systems rather than CAD) and their main hardware platform being UNIX. On the 2D and PC Platform Autodesk, with AutoCAD, was gaining market share.

It was on the 1990s, that the PC explosion happened and with it the raise of a new player. Autodesk had been focusing on the PC platform since its AutoCAD version 1 released in 1982. The licensing of the ACIS 3D Kernel, allowed Autodesk to release in 1993 AutoCAD Release 13. For the first time AutoCAD had 3D Solid Modeling Functions. AutoCAD became widely spread, but other packages like Bentley’s Microstation, soon became strong competitors on the mid-price market. The widespread adoption of CAD by architectural offices was happening slowly and soon would burst into being the dominant trend. We will see more on that on the next post on this series

Sources: CADAZZ, American Machinist

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