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ifcXML4 Release summary

The ifcXML4 release is published as an XML Schema Definition, XSD, derived from the IFC EXPRESS model. The language binding, i.e. the method of how to translate the IFC EXPRESS model into the ifcXML XSD model, follows the international standard ISO 10303-28 "XML representation of EXPRESS schemas and data".


Please note that the configuration settings are mainly of interest to ISO 10303 toolbox providers. ifcXML implementers normally use such toolbox or the fixed content of an ifcXML XSD model.

With IFC4 buildingSMART decided to make more extensive use of the configuration capabilities of ISO 10303-28 in order to reduce some of the overhead coming with the default XML schema binding. Accordingly, a new document has been published describing all configuration settings and its meaning for the ifcXML XSD model.

The ifcXML download package includes the following files:

  • ifcXML XSD model - part of the IFC4 (and later) online documentation(s)
  • configuration settings for translating the IFC EXPRESS model to the ifcXML XSD model - part of the IFC4 (and later) online documentation(s)
  • documentation of used configuration settings (ifcXML4_specification_methodology_V1-1.pdf)
  • configuration schema definition¬†being part of the ISO 10303-28 standard (cnf.xsd)
Another change with the new ifcXML schema is that all required definitions are now integrated in the ifcXML XSD model. Thus, it no longer needs a separate schema with common header and general data type definitions.