Carroll County Times Articles
CAD vs. BIM in Architectural Design
by Dean R. Camlin – October 30, 2005
Computers have been used in the building design professions for over twenty years, since the introduction of the PC by IBM made personal computers practical for small business applications. Now, when most people think of computers as they relate to architectural design they think of CAD or CADD, which variously stand for Computer-Aided Drafting or Computer-Aided Design. In usage, when many people say “CAD,” they are referring to the most widely accepted general computer drafting program, AutoCAD®.
Building Information Modeling
However, in the last five years, as design software has been marketed to take advantage of the more powerful and capable small computers now available, a new acronym has emerged. “BIM” stands for Building Information Modeling. This term more accurately reflects the way computers are now used in the building profession, as tools which allow architects and other building-related designers and builders to work in three dimensions from the beginning of the design, to work out the relationships between building components virtually before the heavy equipment touches the earth.
Increased Flexibility
One of the main activities of an architect has always been the need to communicate his or her design-to the client, to the builder, to reviewing authorities. No longer are we limited to the old, static, orthogonal views of plans, elevations, and cross sections. BIM allows architects and their clients to look at their design from many viewpoints, to spin and flip and slice the model, to explore different arrangements of spaces and finishes as the design is developed. This process can even be animated, allowing the viewer to follow a path through and around the building. Because the design is based on a single virtual model, changes made in one view of the model instantly appear in every view, so the time previously devoted to coordinating one view with all the others may now be spent instead on making the design itself better.
Additional Benefits
Moreover, the pieces used to assemble the building model-the floors, walls, roofs, doors, windows, and other components-have been programmed to “know” what they are. This means, for example, that the computer tells the designer when he has placed a wall in the middle of a window. And when the final design is achieved, BIM can be used to quantify the building materials and their costs.
Another exciting aspect of BIM is that it can go beyond 3D and into the fourth dimension, time. This is used when we are designing an addition to an existing building, and must identify which parts are existing, which are to be demolished, and which are new work.
Now, when talking to your architect, don't mention CAD. Ask instead whether he or she designs using BIM.
About the Author
Dean Camlin is Owner of Dean Robert Camlin & Associates, Inc., and an Advisor for the Carroll Technology Council, a non-profit organization dedicated to educating businesses, government and residents about technology issues. Questions are welcomed and may be addressed in future articles. Email advisors@carrolltechcouncil.org or go to www.carrolltechcouncil.org for a list of Advisor categories.
