Log in   Registration

We are +23 BIM professionals!

Join us>
Do you have any questions?

Need technical support, advice or advice?

  Thursday June 10 2021
  2 Replies
  76 Visits
  Subscribe now

We are currently working on a project that we are managing in BIM management with Revit software.

However, the architect (like most architectural firms) works with ArchiCAD.

This last tried several IFC exports but we have a problem which persists: By opening the IFC on Revit, we obtain several types of elements, having exactly the same properties, on the tree structure of the project as you can see it on the image attached.

Is there a specific export setting on ArchiCAD that will allow identical occurrences to be grouped into a single type of family?

I want to clarify that we tried to open the IFC on Revit using the Improved IFC Import plug-in corresponding to the exchange with Archicad but that did not solve the problem.

I thank you in advance.


I am at your disposal for the analysis of this ifc from Archicad.

BIM management induces a summary work that the agent will carry out in all cases. The agent is also responsible for all deliverables of the group. Managing BIM therefore induces an intimate relationship between the BIM management unit and the agent. Whatever your favorite software is IFC, BCF, XLSX, DXF, etc. are the only formats dedicated to BIM Management.

In the absence of IFC we will speak more of Allplan project management or Archicad project management or Vectorworks project management or in your case of Revit project management.

Why this type of remark? Because exchanging native formats does not or little structuring of openBIM normative aspects, to the detriment of deliverables by phase as well as BIM DOEs. The very principle of a common format was born to overcome this type of mistake.

L'ODA is the support of this quality of IFC export / import. If the European solutions are affiliated to it since the first hour, Autodesk improves its openBIM interoperability via ODA only since September 2020.

"The tool does not make use"
If the agent does not consider itself a strict classification and has not duly configured its IFC export and import translators. There is no doubt that exchanges via this format will be doomed to failure.
Fortunately Archicad is a good student in this area: I plead in favor of a lack of mastery of BIM aspects on the part of the agent.

At your disposal for precise and gracious analysis of course.

Christophe FORTINEAU
Consultant, trainer and AMO BIM
there 2 days
The problem comes in part from the setting and / or the choice of the IFC translator under Archicad, when saving in IFC as well as the complexity of the geometry of the walls of the project.

First of all, ask the architect to produce an export of his model in "Parametric extruded geometry" and not in "BREP". There are two possibilities for this:

Either modify the properties of the IFC translator used, in Archicad
- File -> Interoperability -> IFC -> IFC Translators ...
- Choose the desired translator according to your needs -> set the digital conversion method to "Parametric extruded geometry (if possible)"
- Save the file in IFC by choosing this translator

Either choose a basic translator, already ready, if there is no other criterion for the IFC export:
- Save the file in IFC by choosing the translator "02 - Exact geometry (IFC2x3)"Or"04 - Exact geometry (IFC4)"according to the requested IFC version

A little explanation:
To put it more simply, when you export a wall in "BREP" mode, you create an exact representation of your native model wall, with its cutouts, fits, corner fittings, slab connections, etc. .
But suddenly, each wall becomes totally unique, because no two have exactly the same overall geometry, even if, for you human user, they are of the same nature.
- In this case, Revit has created as many in-situ walls as there are walls in the Archicad model. They are therefore all different types within the meaning of Revit.

Conversely, when you produce an IFC while trying as much as possible to convert the native model into parametric IFC objects, nothing related to the automatic connection, driven by the native modeling software, is exported: the sections , adjustments, connections to slabs, etc. are not generated in the IFC representation. So you end up with linear walls without any attachment.
- In this case, Revit can "read" walls whose compositions are identical (same type), but with constraints of length / height / attachment different from each other. It is therefore Revit which will take care of redoing these connections, if it can / if there is a need.

From this, we deduce that the "Extruded Parametric Geometry" conversion method may not always work, depending on the complexity of the wall, in the native model.
- for example, if a wall has been created with the "Trapezoidal" or "Polygonal" geometry option in Archicad, then this wall, exported to IFC then imported into Revit, will be converted into an in-place wall. It will therefore respond to its own type, unique, and will be identified among other things by its name AND its GUID (that's it, the series of numbers you see at the end of the name of each type of wall in your screenshot. ).
There is no response to this discussion yet.
Be the first to answer it!
Do you have any questions?

Need technical support, advice or advice?

Discover Hexabim services


Your career at N&Co

Find out more



Find out more



Find out more


Log in

The Cron starts