Metrics on the Elasstic project

The EU supported researchproject Elasstic has been using BIMserver to create a new BIM concept in the security domain. During the project BIMserver was used to store IFC data and trigger remote services (now called ‘BIM Bots’). We will go into detail later about the Elasstic BIM concept (that also involved Multi Criteria Analyses for evaluation of simulations based on BIM data). This blogpost is about the metrics of the model and the used BIMserver and GUI plugins.

The BIM in Elasstic was split into 5 different sections. The 5 sections together formed the whole building. They are named ‘ Ribbon 0’ to ‘Ribbon 4’. Within the 5 sections discipline models where created for the disciplines Architecture, Construction and MEP. There was no need for fusion/merging of the models so these plugins where not used.


In the revision that was checked in the latest, the total number of BIM objects that were created was almost 20 million (19.188.069). To give a small indication of the type of objects:

  • 1151 beams were modelled;
  • 1222 columns;
  • 2041 doors;
  • 764 slabs;
  • 1170 spaces;
  • 332 stairs;
  • 2526 windows;

This resulted in:

  • 3.285.133 cartisian points;
  • 5.019.418 ifc faces;
  • The most used IFC object was IfcPolyLoop with 5.019.433 occurrences.

The IfcClassification object was only used 15 times.



The geometry of this latest revision is quite detailed. The metrics about the geometric triangles:


These numbers are after the boolean operations performed by IfcOpenShell.


In total 35 revisions are checked in by 7 different users.

The process of BIMserver use was evaluated by using process mining technology on the event log of BIMserver. This resulted in the following diagram (credits to Stijn van Schaijk):


The project started with a BIMserver 1.2, but during the course of the project was migrated to version 1.3. The GUI plugin was, the IfcOpenShell plugin was used to generate geometry.

The setup runs on a dedicated server with 56Gb RAM memory, 4 CPUs and quite a slow disk.

All objects were able to show in On some operations (selecting) the performance was not user friendly, but the most common usage has acceptable performance.

We had multiple suggestions for optimization of BIMserver which will be evaluated in the 1.4 development.

An impression of the latest revisions of the models:


Release 1.4 final: support for both IFC 2×3 and IFC4

We’ve made the 1.4 release final today. Biggest improvement is the support for both IFC4 and 2×3 in one project (each sub-project can have a different version). Furthermore there are some improvements on memory use and performance.

When you build something on top of BIMserver you have to notice that most of the API calls have changed. Because of the use of multiple IFC schemas it is now necessary to add the schema in most of the API calls.

The IFC4 features have been tested as good as possible. We are used to more intensive testing, but don’t have enough valid IFC4 data to make any guarantees. Any help/data is welcome. The stability of the whole platform, and the usual stability of the IFC2x3 parts are obviously still in there.

We are very happy to announce that this release is in conjunction with and IfcOpenShell. This means the plugins are already updated to the new version of BIMserver, which creates a very low threshold for users.