I talk with a lot of people about ArchiCAD and BIM. One of the common themes that comes up is project size. Comments range from “BIM is only good for large projects” to “program ‘X’ is great for commercial work while ArchiCAD is good for residential projects.” I would love it if I never again have to hear someone say “ArchiCAD is great for small projects, but not giant ones.” Hopefully this post will help with that. ArchiCAD is of course great for residential projects. And it is true that in the USA, ArchiCAD has its biggest presence in small scale firms and small scale projects. But ArchiCAD is great for all scales of projects. And for firms of all sizes as well. Now it’s best to steer clear of directly comparing BIM software and avoid making statements about superiority. BUT if I may digress for a moment and do the opposite of what I just warned… Teamwork 2 is the best out there for working with large, complex teams. Instant messaging built into the program, an easy request/release/reserve element reservation system, model syncing so light and fast that it can be done with a laptop connected to a smartphone. It just can’t be beat by anything else out there right now.

It’s not about Scale, it’s about Complexity

In discussions of BIM and the capabilities of a particular software, scale is a bad determinant of value. Instead we need to distinguish between large and numerous. Our concepts of big are not the same as the computer’s perception of big. Imagine two beams modeled in ArchiCAD. One is a mile long and the other just an inch long. If they are simple rectangular beams, they are essentially the same thing to ArchiCAD. The scale is inconsequential and both are just elements consisting of 6 polygons. If there are 30 holes in each beam, still no real difference. If one beam has 300 holes and the other has zero holes, it’s the beam with more holes that will carry more weight in the project (file size, rendering speed, element management, polygons, etc.), not the one that is physically bigger. It’s not too hard to imagine a basic urban planning model that is made up of 50 objects that represent buildings. Likewise, an average kitchen in a residential project could have 50 objects in it (and each of those objects could have way more polygons and materials than the 50 dimensionally larger buildings). So instead of discussing big or small scale projects, we need to think about Complexity. Can ArchiCAD handle a wide range of complexity, from low to high? Most definitely. Here’s a flashy example of a larger scale complexity. And here’s something most smaller firms deal with:
ArchiCAD for big projects
Just like I talked about in this post, it’s Order vs. Chaos and Simplicity vs. Complexity as a matrix that is interesting. It is not Big vs. Small that matters (scale of size). Scale and Complexity are related though.  At this point it is time to introduce one more term, and that’s Grain. Grain is the description of how refined a model is. Is the project coarse, blocky and abstract or is it highly detailed?

Grain x Size = Total Complexity

Skyway OpenHow a BIM program handles fine grain, regardless of size is what really matters (as grain of detail in the above equation is going to drive the Total Complexity more than size). For example the size of a project probably goes from 1 (piece of furniture) to 10 (building) to 100 (city), but really we’re typically working in the 1 to 10 range. With Grain (Complexity of Detail) we have a similar scale of 1 (masses) to 10 (1/4″ geometry/data) to 100 (complete information). With Grain, we might do early design below 10, but most of the time we’re living in that 10 to 100 range, and striving for as high as we can go. The scale is fixed, more or less. And often the smaller the scale, the finer the grain. When I was designing mini-golf holes for the US Bank Skyway Open in Minneapolis, my scale was small (7′ x 14′ max), but my Grain was high extremely high; I modeled every screw.

Using BIM is about knowing what to add and where to stop

When I’m working on custom residential, I model every piece of trim in every room. All the baseboards, crown modelings, cabinet pulls, etc. It’s all there in high detail. My guess is that if you’re doing documentation for a 1,000,000 sq ft. project, you wouldn’t necessarily do the same for every room. There is probably a smarter way to abstract that data down in a manner that doesn’t involve modeling each piece yet still gets the information in the drawing set (perhaps by just scheduling typical base, crown, and window trim in a room schedule linked to Zones). It needs to be stated though that extremely high Grain can be the undoing of any project. If Grain gets out of control, then the Total Complexity can explode. And if your template and discipline (Order) can’t handle it, you will lose control of your model and your project. And it’s worth noting that you’ll probably be overwhelmed by the complexity of a model before ArchiCAD is. The biggest danger is that the design process will shut down as all your energies go toward maintenance of the model. This of course isn’t inevitable. You just need to manage and balance Grain, Scale, and Order to keep Complexity in check.

An Ounce of Prevention…

If you’re in early schematics, instead of modeling everything, it might be best to work with just Zones. Or just Morphs. Or simple walls and only ever look at the floor plan. Or include dumbed-down placeholders. In other words, early in the project you need to abstract and focus on what is important, just like you did with a pencil on trace paper. Whether the early design is about space requirements (Zones), geometric requirements and forms (Morphs), energy data (integrated Energy Evaluation), or some other core functionality, ArchiCAD can handle the basics at the beginning of the design. And then those can all evolve as the project gets more complex. For more advice on managing complexity during early design, check out this post by Stefan Boeykens. I’d list my favorite of his ten tips but they are all so darn good.