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IFC4 Add1 Release

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IFC4 Addendum 1

Official landing page to publish the official IFC4 Addendum 1 release. it is a buildingSMART Final Standard.


Quick link for developer

IFC4 Addendum 1 Final
»access EXPRESS file« »online access to HTML documentation«
»access XSD file« »download of HTML documentation (90MB)«


What is new in IFC4 Addendum 1 ?

The main purposes of the IFC4 Addendum 1 are the improvement of the specification documentation and the necessary enhancements of the schema that resulted from the pilot implementations and the first Model View definitions. All changes made are downward compatible.

  • The documentation format has been further improved for readability. A language independent section to describe the entities and types with their attributes and relationships is now available and separate to the EXPRESS and XSD code;
  • The use of concept templates (chapter 4) and concepts is greatly enhanced, based on the mvdXML specification to enable better MVD developments and validation;
  • Minor schema enhancements reflect the experience from pilot implementations of the IFC4 enhancements;
  • One additional schema enhancement has been added after intensive discussions and considerations, a simplified and far more compact definition of poly lines with arc segments
    • See the following »summary« of the rationale behind adding this additional geometry definition
  • An overview of all changes is provided »here«
  • A detailed listing of all issues resolved for the beta release is shown »here«


IFC4 Add 1 for MVD development

  • the first official Model View Definition for IFC4 will be based on the Addendum 1. Therefore all upcoming buildingSMART International IFC Certification are based on IFC4 Addendum 1.
  • see IFC4 Reference View and IFC4 Design Transfer View as the first two bSI MVD's based on IFC4 Add1.



IFC4 Add 1 under ISO16739

  • it is planned to create a new work item for a first Amendment of ISO16739 under the ISO59/SC13 Joint Working Group 12 (JWG12).
  • the goal would be to approve the same enhancements as ISO16739 Amendment 1