Revit 2021 - IFC Mistake

[an.borcheva]

Hello everyone,

I really hope, that I get any help or comments to my problem...

First of all it’s important to say – this topic is not about the IFC export bug that was reported here:

https://forums.autodesk.com/t5/revit-architecture-forum/ifc-export-issue-revit-2021/td-p/9438686

Here is the small prehistory:

In the last two projects in RVT2020 we used the IFC Add-in from Autodesk (IFC 2020) and struggled with errors in the exported PSets (some instance parameters for windows were not exported in a PSet, I reported about this last year). It took me so long to understand that the problem was with the IFC Add-in... A few months ago I finally discovered that and got a clean model in IFC with a full PSet for all of windows in our project just using the native Revit 2020 IFC Export.

Last week we installed Revit 2021. I didnt install the IFC Add-in (IFC 2021), because I knew, that it's already caused problems in the previous version. 

And what I've got? I got the same problems with the PSet or rather with the instance parameters of windows exporting the IFC from the NATIVE Revit 2021 IFC Exporter.

Here are two screenschots with the same PSet file. As you can see, in RVT2020 we had all of the windows parameters under "CG-Attribute". In RVT2021 its not more the same.

Is there anything about 2021 (in spite of bugs reports about the missing PSets from last year?), that I dont know?

We have the last updated version of RVT2021, where all the mentioned bugs should be solved...

Thank you in advance for any, any help!..

[an.borcheva]

Just to mention:

This is the problem, that we had in RVT2020 using the IFC2020 Exporter:

https://knowledge.autodesk.com/de/support/revit-products/troubleshooting/caas/sfdcarticles/sfdcartic...

[syman2000]

Have you try ArchiCAD IFC export from Revit? See if that helps you solved your issue.

https://graphisoft.com/downloads/interoperability

[an.borcheva]

Hello @syman2000

thank you for the answering.

I've just tried it with the Archicad IFC Exporter, bud it didnt solve my problem. Sorry...

[TripleM-Dev.net]

Hi @an.borcheva ,

Could you share a project file with the window and the used pset.

We don't have a issue exporting IFC with multiple parameter of mixed datatype and Type/Instance based in Revit 2020/2021. I have tested a project file, and it exports the IFC almost identical (only a few bytes difference)

- Michel

[an.borcheva]

Hello Michel,

thank you for the help. Ill do it on Monday then.

But I can say already, that the reason probably is, that we divide modell layers (isolation and bearing walls), and then connect them with each other, so we have a window opening in both walls. I wrote about it here: https://forums.autodesk.com/t5/revit-architecture-forum/ifc-export-pset-only-type-parameters-exporti...

As already written, as I uninstalled IFC 2020 in Revit 2020 I didnt have this problem anymore. Its not always possible to avoid or adjust wall connections, especially by a huge amount of windows. 

Thank you and have a good evening,

Anastasia

---

@TripleM-Dev.net wrote:

Hi @an.borcheva ,

Could you share a project file with the window and the used pset.

We don't have a issue exporting IFC with multiple parameter of mixed datatype and Type/Instance based in Revit 2020/2021. I have tested a project file, and it exports the IFC almost identical (only a few bytes difference)

- Michel

---

[an.borcheva]

P.S. The reason is also, when I have e.g. two bearing walls in one line and one isolation wall for both of them. In this case, if these two walls are connected/joined with the isolation layer, it can cause a missing instance parameter. But not always the case, so, everything is pretty random...

[an.borcheva]

Hello again Michel,

so, I've tested today a non-project model, so I modelled in a new file the similar house part to be sure, that the reason is not in the project file. Unfortunately I've got the same result.

I've attached here all the files:

1. The test model in RVT2020;

2. Screenshot: IFC from the model RVT2020 (here I don't have any problems, type and instance parameters "Type" and "Number" are exported with the PSet);

3. The test model in RVT2021 (updated RVT2020);

4. Screenshot: IFC from the model RVT2021 (there're 4 windows with missing instance parameters);

5. PSet for windows;

I would really appreciate, if you have any ideas, what I should do in this situation...

Anastasia. 

P.S. You find the rest of files below.

[an.borcheva]

2. Screenshot: IFC from the model RVT2020 (here I don't have any problems, type and instance parameters "Type" and "Number" are exported with the PSet);

5. PSet for windows;

[TripleM-Dev.net]

Hi @an.borcheva ,

I did a quick inspection;

It seems I'm missing the "Kennzeichen" and "Typenkommentare" parameters in the project files (2020 and 2021).

I do see that "Type Comments" has the value of the Type (= Typenkommentare)

Maybe a Language issue?

I've attached screenshots of the instance properties and the type property "Type Comments"

ps. In the Pset only instance parameters would be exported, so the Type Comments wouldn't be exported...

[TripleM-Dev.net]

Hi @an.borcheva,

Thinking it may be a Language issue (for the builtin parameters) I changed the Pset to use "Mark" and "Type Comments" as these have the values in from the post.

I encountered strange results, the Type Comments shouldn't export (as the pset only sets I(nstance)).

And the Mark, the instance value doesn't get exported. It does behave the same in Revit 2020/2021 with the custom exporter.

I did manage to export the values, I changed IfcWindow to IfcElement, see attachment.

I haven't noticed this because we only use IfcElement in our Psets.

- Michel

[an.borcheva]

Hello Michel,

thank you for the answer!

Yes, it's because of the language, sorry, I should've clarified it earlier. I've used "Mark" (Kennzeichen) as an instance parameter and "Type Comments" (Typenkommentare) as a type parameter. Thank you for the translated screenshots 🙂

As I know, the I and T in Pset make no longer any difference... So I always got both of them only with the mentioned "I". But I've checked it once more with the defined "T" and "I" and got the same. It also doesn't answer the question, why I get by some of windows instance + type parameters, and by others only type parameters. 

P.S. I've attached the english version of PSet with the defined T and I.

Thank you once more,

Anastasia

[an.borcheva]

Hello Michel,

thats amazing, I've got it too just using IfcElement... I could've never thought that's the reason...

I can't wait till I'll try it tomorrow with the project modell 🙂

Thank you so much for your time!..

[TripleM-Dev.net · Accepted solution]

Well actually IfcWindow should have worked, this is a Bug in the Exporter or Revit.

I did some further testing.

Turns out that even in de default Revit template when drawn 2 walls and joined with a window placed the instance parameters don't export to a User Pset, unjoin the Walls and the instance parameters do export with the IfcWindow class in the User Pset.

Exporting all Revit Psets will export the values to their Revit's Pset or when using IfcElement and not IfcWindow.

[an.borcheva]

Hello Michel,

yes, exactly.

Exactly this thing with the joined walls I mentioned last year. Unfortunately I was sure that this was the only and real problem and struggled with that a lot, although there is a better solution, as you already wrote.

Exporting all Revit Psets is also a good way, in our case it's by client required, that we export only necessary Parameters with the help of user(client) defined PSet.

So, I find IfcElement instead of IfcWindow till now as the best solution. Although it would be better, if the bug will be fixed later by Autodesk.

Thank you once more and I gladly accept your help as solution.

[dyildirimM97W3]

WEll I don't understand why we have this many bugs in a software package we pay 10.000$ per year.