In our article Prediction of BIM Being Used on More Projects is Wrong, we shared results of a survey question that asked about how many projects included 3D collision detection in them. One objection to the survey is that 3D collision detection is not the same thing as BIM.

We agree. BIM and 3D collision detection are not the same thing. BIM includes a lot more than just 3D collision detection. It is possible to do BIM without 3D collision detection. Also, it is possible to do 3D collision detection without using BIM.

The ven diagram below represents what we think the projects that use BIM and 3D collision detection look like. The red circle represents projects done using BIM. The blue circle represents the projects done using 3D collision detection.

The little sliver of red represents the projects done using BIM without using 3D collision detection. In theory you could do it, but that’s not what anyone in the industry means when they talk about BIM.

The blue area represents projects that include 3D collision detection that do not include BIM. Those projects exist. However, including them in our survey results means we overestimate how often BIM is currently being used.

The reason we asked about 3D collision detection rather than use of BIM is because BIM is a very vague term. Finding a consistent definition that everyone taking the survey understands is nearly impossible. 3D collision detection, on the other hand, is a very distinct concept. Some details will vary between firms implementing it, but it is consistent within the industry.

Asking about 3D collision detection allows us to receive answers that can be compared between respondents without having to wonder about definitions.