Defining BIM, CAD, & VDC

Defining BIM, CAD, & VDC

The world of construction is full of abbreviations and acronyms. In this industry, we speak our own language. How many times, while telling a story about work to family or friends, do you stop to define an abbreviation or acronym your co-workers would know instantly? 

If you’re in the industry, you accept that few outside of the industry can converse in our language. Or even understand it, at times. And that’s okay. We don’t mind. We get it. It’s all part of this fast-paced, short on time, heavy in detail industry. 

However, the rub can come when you’re in a conversation with others in the industry and you’re the one not fully understanding the abbreviations and acronyms. This is your world. You have to speak it. But, with the onslaught of technological shifts, there may be a few terms that you understand…only to a degree…or aren’t comfortable with conversing on at all. Three, in particular, represent the change agents in our industry. That’s CAD, BIM, and VCD. They represent the influx of computer technology into the construction industry. You may even know what they stand for but not fully understand what they mean or all they encompass. When conversations shift in that direction, you may find yourself at a loss to fully comprehend what is being referenced. 

So, to keep our communication strong and easily understood, I wanted to take you through these three terms and give some background on what they are, whey they’re important, and how they affect our industry now and in the future. 


First up, CAD. 

CAD: Computer Aided Drafting

If you had to pick the founding father for the integration of computer technology into construction, it’d be CAD. It’s the original, the starting point. It came on the scene in the late 70s, early 80s to streamline the drafting process. 

Before CAD, drafting guys almost needed an artist’s skill. They needed to create exactness in their drawings, right down to the letter “r”s on their blueprints having the same height. They needed an almost robotically steady hand to simply create those crucial straight lines. The problem? Not everyone is Walt Disney. Many had to rely on letter templates, for example, to get that uniformity. Then, if they messed up to a point that couldn’t be erased or spilled coffee on their drawings, they had to start all over from the beginning. 

It was a time-consuming, patience-requiring skillset that not everyone had. 

Enter the computer. 

My dad, who was the draftsman who taught me drafting, got started in CAD early on. His firm spent $30,000 for a CAD station, while the majority of the workers at the time considered to be a gimmick. But Dad jumped on early, realizing he could do the design and drawings himself without needing to hire a draftsman or fund a drafting department. With computers, if you made a mistake, you hit the undo button. This little button, which was added in 1996 to the main computer-aided drafting software, Auto Cad, was the greatest invention to drafting since the pencil. 

After that, CAD changed everything. Now, people without good penmanship or by-hand drafting abilities could work in drafting. By the 2000s, 3D versions of CAD started coming on the scene. By the mid-2000s, we started seeing our second term, BIM, emerge.

CAD model
cad blueprint rendering

Next up, BIM

BIM: Building Information Modeling

With the invention of BIM, drafting shifted from 2D lines, which represented plumbing or ductwork, to actual 3D modeling. Instead of lines, I can model actual walls. All with the exact properties. Need a 4-inch stud wall with 5-inch sheetwork? I can show you what that will look like…exactly. Through BIM, I can model that all with the intelligent properties. 

Since I mentioned Walt Disney earlier, let me give you an example of what I mean. Do you remember Julius (the Cat)? He was the first animated series created by Walt Disney. He moved around, getting himself into all these funny situations. But, he was flat. There was no depth to the drawings. Not, yet. 

Then, in 1937, along came Walt Disney’s first full-length animated film, “Snow White and the Seven Dwarfs.” By taking hundreds of flat drawings and filming them from different angles with different equipment, Disney gave his animated movie’s depth. Characters and activity could be happening in the background, while Snow White moved about the forest. It was another huge shift in the technology used for animated films, which ultimately led to Pixar, which is computer generated modeling in 3D. 

bim modeling
bim model for plumbing

That’s the difference between CAD and BIM. Instead of putting lines on paper, we’re putting real 3D content into the drawings with real information behind it. This also allows us to auto-generate schedules and pull information from that exact content. It also opens the world to 3D coordination, 3D building, and implementing virtual reality into construction.

And that takes us to VDC.

VDC: Virtual Design Construction

Look at VDC more as an all-encompassing term than a specific program or tool. VDC is a process of pulling together all the tools, possibilities, and services that are included in virtual design construction. For example, VDC could include any tool that falls under the digital construction umbrella, such as the use of drones to fly over the site and take measurements, the use of software for job scheduling and man hours, the use of robotic layout to map out areas to mark for plumbing installation, the use of Microsoft HoloLens to walk the site using virtual reality, the use of 3D scanning to take precise measurements and map out installation needs, and, eventually, even the use of 3D printing. 

VDC is the term that encompasses the use and management of all these tools, as well as so many more already invented and those yet to come. 

Thanks to technology, the world of construction continues to enjoy more time saving, cost saving services, all while also offering greater accuracy. Hopefully, this walk through the development and definitions of that technology will help answer your questions. If not, ask me directly! Leave a comment or a question at the end of this blog and I’ll get back to you as soon as possible. 

Talk to you later,


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