# Provision for Void

The use of proxy objects has largely been established in the preliminary design and coordination of cut openings in an integrated design process. In IFC those objects are called “provision for void” objects and are exchanged between domain models together with alphanumeric information and dimensions.

Proxy elements originate either from native Revit opening elements or are simple families with a void.

To export a provision for void object, the IfcExportAs needs to be set to *IFCElementProxy* and IfcObjectType to *PROVISIONFORVOID.*

<figure><img src="/files/J8DnAHTqrVPIowFlsWUX" alt=""><figcaption><p>IfcExportAs mapping in Revit 2024 and newer</p></figcaption></figure>

<figure><img src="/files/xXDFsYsIK7RPZScNZA2g" alt=""><figcaption><p>IfcExportAs mapping before Revit 2024 and result in IFC</p></figcaption></figure>


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