# IFCBUILDINGELEMENTPROXY - 6th parameter to be default

**URL:** <https://forums.buildingsmart.org/t/ifcbuildingelementproxy-6th-parameter-to-be-default/5260>\
**Category:** Uncategorized\
**Created:** [March 25, 2024, 3:22pm UTC](https://forums.buildingsmart.org/t/ifcbuildingelementproxy-6th-parameter-to-be-default/5260 "2024-03-25T15:22:41Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![LPr](https://avatars.discourse-cdn.com/v4/letter/l/9dc877/32.png) [@LPr](https://forums.buildingsmart.org/u/LPr)\
**Post date:** [March 25, 2024, 3:22pm UTC](https://forums.buildingsmart.org/t/ifcbuildingelementproxy-6th-parameter-to-be-default/5260/1 "2024-03-25T15:22:41Z")

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Hello,  
I have a sample which uses

```auto
  /* #1000= IFCBUILDINGELEMENTPROXY('1kTvXnbbzCWw8lcMd1dR4o',$,'P-1','sample proxy',$,#1001,#1010,$,$); */ /* <<<< This was OK */
     #1000= IFCBUILDINGELEMENTPROXY('1kTvXnbbzCWw8lcMd1dR4o',$,'P-1','sample proxy',$,$ ,#1010,$,$);

```

I don’t want to specify the 6th parameter to IFCBUILDINGELEMENTPROXY - the global coordinate system is to be used.  
The [Standard](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcBuildingElementProxy.htm) states that 6th parameter is optional - but how do I write it? Itried ‘$’ etc., but the IFC validator always complains ([Validator](https://validate.buildingsmart.org/report_syntax_schema/KnThDdsADBaknhAeQBbSNykUfTEJpZWc)).  
TIA.

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<div class="post-metadata">

**Author:** ![aothms](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@aothms](https://forums.buildingsmart.org/u/aothms)\
**Post date:** [March 31, 2024, 1:35pm UTC](https://forums.buildingsmart.org/t/ifcbuildingelementproxy-6th-parameter-to-be-default/5260/2 "2024-03-31T13:35:58Z")

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True. There is a formal rule in the schema defining that “If a Representation is given being an IfcProductDefinitionShape, then also an ObjectPlacement has to be given”.

[https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcProduct.htm#5.1.3.10.4-Formal-propositions](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcProduct.htm#5.1.3.10.4-Formal-propositions)

But the placements in IFC are typically hierarchical following the containment+decomposition structure of the building. So what you can do is relate to the placement of the IfcBuilding (for example) with an “identity” relative placement (Location=0,0,0; Axis&RefDirection=$)

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**Author:** ![nn1](https://avatars.discourse-cdn.com/v4/letter/n/ebca7d/32.png) [@nn1](https://forums.buildingsmart.org/u/nn1)\
**Post date:** [April 1, 2024, 7:49am UTC](https://forums.buildingsmart.org/t/ifcbuildingelementproxy-6th-parameter-to-be-default/5260/3 "2024-04-01T07:49:20Z")

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I wonder if you are trying to describe a library object? This have representations but no location. So you need IfcBuildingELementProxyType.

You should also review the subtypes of IfcElement(Type) to find out something better than IfcBuildingElementProxy(Type).