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IFC Development Monthly Call - 18 June 2020

Greeting buildingSMART Technical Community,

The next meeting will be 18 June 2020, 13.00 UTC/GMT

The topic for this meeting: Late Binding Solutions
Please refer to

Topic summary:
In the technical roadmap the modularization of IFC is discussed in detail. Modularization of the schema makes it easier to separate responsibilities, distribute the maintenance of the entities, and possibly even have separate release cycles per module. The specialization structure of IFC makes it possible to have dynamic (‘late binding’) modules that extend the base layer.

When the shared base layer is implemented in full, no matter what module the software supports, interoperability between domains will be guaranteed. Furthermore, modules could include extensions to define additional classification and properties on top of the shared layer.

The split could be done on all specializations from IfcBuiltElement, or possibly on IfcProduct when the implications are not too drastic. Other class branches, like IfcControl and IfcProcess, need to be reconsidered as well.

We would like to use the IFC Development call of June to gather ideas, concerns and contributions to this new architecture of IFC. This includes, but is not limited to, ideas such as:

  • Where should the base and extensions be cut?
  • What does this mean for the class hierarchy?
  • Can relationships also be part of the ‘late binding’ extensions?
  • Can higher order object types be used?
  • How to deal with ‘virtual objects’ like space boundaries?

All these topics are connected and need a holistic approach. A small team has been working on these issues for 2 months and will share some first ideas. Other contributions are also very welcome!

Send your slides (maximum 5) to at lease 24 hours before the meeting.

The meeting will be held via GoToMeeting (Note that there is a limit of 150 attendees) and recorded for others to review and comment. Interaction for this one will be limited, but use of the Chat function will enable us to capture questions and answer them later, if we don’t get to them in the meeting.

IFC_Dev_Mtg-June2020.ics (4.8 KB)

IFC Development Monthly Call

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If there are any questions, please let me know.

@berlotti has worked out an agenda and presenters. Please note that this will like be a two-hour meeting.

IFC5 modernization presentation Agenda

  1. Introduction / objectives (@berlotti )
  2. late-binding on BuiltElements, Property Names and Relationships (@pasi.paasiala )
  3. Class breakdown structure / hierarchy redesign (@TLiebich )
  4. How to represent this as IFC - modelling restrictions on entities (@aothms )
  5. How it all comes together (@Arie_van_Kranenburg )
  6. Q&A (All)

From @berlotti

The meeting recording about IFC5 Modernization is now available on the buildingSMART Vimeo portal.

We will send an update later for the parts of Arie’s presentation that didn’t show correctly.