Handling the IfcProject in a big project

[agroni]

Hi everyone,

i have a very specific question about IFC exchange in a bigger project. It is a case that chases me in my career and so far, did not seem to find the right answer.

The project has different levels for the ground floor (aprox. +1,5m) and we might need to model these two structures separately and connect them with modules. This is the easy part and can be done well in archicad by hotlink. My question concerns more the IFC Structure, since in this case we would be exporting two separate IFC Files, meaning two IfcProjects. These separate IFC Files have a defined IfcBuildingStorey and its appropriate heights, the IfcBuilding with the correct altitude level and the IfcSite (look @ IfcBuilding) . These Enteties can be repetitive in a single IFC Structure, as seen in the IfcBuilding (with Building[1] and Building[2]. But the IfcProject on the other hand must be a single unique entity in the structure which is defined by IfcSingleProjectInstance (look @ IfcProject). The above mentioned cases are based on IFC4. In IFC2x3 the description is not so ritch but I would assume it applies as to IFC4.x

So, when federating these two IFC Models in a CDE, I would get two IfcProjects that have different GUIDs, meaning they are not the same. Or is the Name attribute of IfcProject more important to define the common project here?
As far as I know, in Archicad it is not possible to have one single project and export a part of it in IfcBuilding[1] and another part in IfcBuilding[2].
Or would you simply try to model the whole project in one file, ignoring the height difference and export a single IFC?

[Laszlo Nagy · Accepted solution]

Please watch this short clip, it may have the answer to what you are looking for:

[agroni]

Thanx Laszlo for your reply. You have hit the spot with your answer
Actually I am a bit ashamed, that this this was already made possible in AC19. Nonetheless, I need to check our office template if we did not loose these parameters on the way up to 22

[agroni]

Hi Laszlo.....again

sorry to bother you again with this case, but for some reason I am not able to get the models into one structure as it is shown in the video. In the video it is clear how it is done, but when exporting an IFC from AC22, the GUIDs are the same for IfcProject and IfcSite, whereas the IfcBuilding differs, but Solibri does not check this thing. Also tried it in BIMcollabZoom and same results.

Is something going wrong with the export?

[Laszlo Nagy]

I have not checked it myself, but if you fill out all those field as shown in the clip, it should work. If it does not work, then there may be a bug somewhere.

[agroni]

I have information from my sources
Apparently there are some seconds missing in this video. In those missing sequences the user merges all IFCs in Archicad and then does an IFC Export.
This would make then sense in Solibri, why there is only one IfcProject and the structure develops.

I have tried many ways to see in Solibri just one structure. On the other hand, I believe that Solibri is not design to simulate a CDE where you would probably see this single structure of the project.

So, the case is half closed

[Laszlo Nagy]

The video at around the 3 minute mark says that you export an IFC file from all three ARCHICAD project files separately, and then you use an application that is capable of merging multiple IFC files into a single IFC File. Then you can open the resulting single IFC file in Solibri or other IFC viewer application.

[Karol Argasinski]

Hi Guys,

And what about GUIDs in each of the model, after importing them into Center File? If they will change, it is hard to actually do clash detection.

Cheers,
Karol

[Laszlo Nagy]

Did you see a change in GUID?
You can also use the IFC GUID, which I think will stay the same even after the IFC files are merged (federated) into a single IFC file.

So, just to clarify: you do not merge the ARCHICAD files into a single ARCHICAD file and then export as IFC.
You Export as IFC from each individual ARCHICAD Project, then you use a 3rd party software to merge the 3 resulting IFC files into a single IFC file (you federate the models). There are various applications on the market that can do that.