One of the first terms you come into contact with when dealing with BIM is certainly IFC - Industry Foundation Classes.
The format is developed by buildingSMART, the independent association for open standards and specifications. IFC is described as follows on the German-language website of buildingSMART:
The buildingSMART data model, also known as Industry Foundation Classes (IFC), is a general data schema that enables the exchange of data between different proprietary software applications.
Source: http://www.buildingsmart.de/bim-know-how/standards
Sounds promising at first! Until the moment a planning partner calls you and says: "I have imported your IFC from software X into my software Y and some of my windows / walls / etc. are just stupid objects! That can't be right - IFC must provide me with an error-free and perfect model in every software!"
Is that really the case?
The truth is: maybe it will one day really be that far. Today, however, we must bear in mind that IFC is a very young format and the BIM modeling tools (Revit, ArchiCAD, Allplan....) create building data models with a high degree of intelligence that simply cannot always be covered by the IFC format. In addition, each of these programs naturally uses its own form of intelligence.
This diagram from buildingSMART illustrates the problem quite well: IFC 2×3 is the currently valid standard, IFC4 is still relatively new and is still being implemented by most manufacturers - so we are still pretty much at the beginning of development:
Source: https://www.buildingsmartcanada.ca/open-standards/
The conclusion: it's generally not down to the software or the interface, but simply the discrepancy between highly parametric BIM systems and a format that still has a lot to learn. So it remains exciting 😉