BIM – Worthy of clearer definitions

Building information modelling (BIM) is the latest term to be elevated to a certain level of importance in geospatial information, urban planning and architectural design.

BIM has nearly reached the status of “GIS.” Consequently it’s attained a level of confusion among users about its true definition and application. I heard one practitioner this week at Bentley’s Year in Infrastructure conference question whether BIM has been around forever except we just used to call it “3D”.

From the same practitioner came the question of why the construction industry has also been so reluctant to change to a BIM/3D workflow? Some, he said, believed it was somewhat generational; others just a “high tech workflow focused on facility management.” Still others’ questioned the need for such precision: “If construction of buildings is imprecise do we really need BIM?”


Greg Bentley, CEO of Bentley Systems, began his address to users who attended the conference with his own definition:

  • “B” he said was for  “better decisions from a depth of information modelling (via simulation + visualisation)
  • “IM” he said stood for “information mobility for better performing projects”. That is, how well users can obtain better collaboration through mobile platforms and apps 


In this video, between time marks 37:00 and 39:00, you can hear Mr. Bentley’s more thorough definition of BIM. So, you can see that even companies promoting BIM want to reach a higher level of understanding among its users so that they can better proselytise the concept.


Now, whether you take Mr. Bentley’s definition or a more rigid definition of BIM as per the National Building Information Model Standard Project Committee which uses the following definition (Wikipedia):


Building Information Modelling (BIM) is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition.


I also happen to like this further refinement from Wikipedia:


BIM covers more than just geometry. It also covers spatial relationships, light analysis, geographic information, and quantities and properties of building components (for example manufacturers’ details).


But the practitioner I listened to gave a more direct reason for adoption of BIM for design and analysis:


“Precise 3D analysis gives huge time savings that 2D does not”. He was referring to workflows that need constant checking of alignment and design that would require the architect or planner to constantly refresh different views of the same area. A BIM approach allows you to work directly in the 3D space from the outset. While there is upfront time in constructing a 3D model, it will pay time dividends in the future.

By Joe Francica, Editor-in-Chief & Vice Publisher, Contributing Blogger to APB.

Original article can be found at:


Editor’s Note: Bentley Systems provided support for travel expenses to the Year in Infrastructure event.