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IFC4 Add2 Release

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IFC4 Addendum 2

Official landing page to publish the official IFC4 Addendum 2 release. The IFC4 Add2 is published on 15th July 2016 as a buildingSMART Final Standard.


Quick link for developer

IFC4 Addendum 2 Final
»access EXPRESS file« »online access to HTML documentation«
»access XSD file« »download of HTML documentation (101MB)«


What is new in IFC4 Addendum 2 ?

The main purposes of the IFC4 Addendum 2 are the improvement of the IFC4 Add 1specification documentation and the necessary enhancements of the schema and property sets that resulted from the ongoing pilot implementations of the first two Model View Definitions, the Reference View and the Design Transfer View. The main change related to improvements to the tessellated geometry for the Reference View, and the advanced boundary representation geometry for the Design Transfer View. All changes made are downward compatible.

  • Two additional schema enhancements have been added after intensive discussions and considerations:
  1. new subtype of tessellated geometry enabling planar and polygonal boundaries with inner loops
  2. new elementary surfaces and intersection curves for more stable definitions of advanced b-rep's (NURBS)
  • The documentation format has been further improved for readability. More interlinked definitions, now including property and quantity sets, ifcXML files for all examples, in addition to IFC files, etc.;
  • The use of concept templates (chapter 4) improved, updated to Version 1.1 of the mvdXML specification and including the snippet of the mvdXML for each template;
  • The use of concepts at relevant IFC Entities, including the snippets of the mvdXML specification for each concept root, optimized for documentation of the requested functionalities;
    • NOTE This part is currently still experimental and focuses on documentation of concepts, it requires further improvements before being used for automatic IFC file validation purposes;
  • An overview of all changes is provided »here«
  • A detailed listing of all issues resolved for the beta release is shown »here«


Anticipated use of IFC4 Addendum 2

IFC4 Add 2 for MVD development

  • the official Model View Definitions used in the IFC4 certification will be based on the Addendum 2. They will have the version number 1.1.
    • IFC4 Design Transfer View V1.1
    • IFC4 Reference View V1.1
  • both MVD's are updated now to use the Add 2


IFC4 Add 2 under ISO16739

  • a new work item for a first Addition of ISO16739 under the ISO59/SC13 Joint Working Group 12 (JWG12) has been approved.
  • the goal is to use IFC4 Add2 as the source of ISO16739 Addition 1