IfcRelVoidsElement

Item	XML	Change	Description
IFC2x3 to IFC4
IfcRelVoidsElement
OwnerHistory		MODIFIED	Instantiation changed to OPTIONAL.
IFC4 Addendum 2
IfcRelVoidsElement
RelatingBuildingElement	X	MODIFIED	Xsdformat changed from Attribute to Hidden.

Semantic definitions at the entity

Entity definition

IfcRelVoidsElement is an objectified relationship between a building element and one opening element that creates a void in the element. It is a one-to-one relationship. This relationship implies a Boolean operation of subtraction between the geometric bodies of the element and the opening.

As shown in Figure 177, the insertion of a void into a wall is represented by the relationship IfcRelVoidsElement. The opening is created within the wall by IfcWall(StandardCase) o-- IfcRelVoidsElement --o IfcOpeningElement.

Figure 177 — Relationship for element voiding

HISTORY New entity in IFC1.0

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
5	RelatingBuildingElement	IfcElement		Reference to element in which a void is created by associated feature subtraction element. IFC2x CHANGE The data type has been changed from IfcBuildingElement to IfcElement with upward compatibility for file based exchange.	X
6	RelatedOpeningElement	IfcFeatureElementSubtraction		Reference to the feature subtraction element which defines a void in the associated element. IFC2x CHANGE The data type has been changed from IfcOpeningElement to IfcFeatureElementSubtraction with upward compatibility for file based exchange.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcRoot
1	GlobalId	IfcGloballyUniqueId		Assignment of a globally unique identifier within the entire software world.	X
2	OwnerHistory	IfcOwnerHistory	?	Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object, NOTE only the last modification in stored - either as addition, deletion or modification. IFC4 CHANGE The attribute has been changed to be OPTIONAL.	X
3	Name	IfcLabel	?	Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule.	X
4	Description	IfcText	?	Optional description, provided for exchanging informative comments.	X
IfcRelationship
IfcRelDecomposes
IfcRelVoidsElement
5	RelatingBuildingElement	IfcElement		Reference to element in which a void is created by associated feature subtraction element. IFC2x CHANGE The data type has been changed from IfcBuildingElement to IfcElement with upward compatibility for file based exchange.	X
6	RelatedOpeningElement	IfcFeatureElementSubtraction		Reference to the feature subtraction element which defines a void in the associated element. IFC2x CHANGE The data type has been changed from IfcOpeningElement to IfcFeatureElementSubtraction with upward compatibility for file based exchange.	X

#	Concept	Template	Model View
IfcRoot
	Identity	Software Identity	General Usage
	Revision Control	Revision Control	General Usage

Formal representations

XML Specification

 <xs:element name="IfcRelVoidsElement" type="ifc:IfcRelVoidsElement" substitutionGroup="ifc:IfcRelDecomposes" nillable="true"/>

 <xs:complexType name="IfcRelVoidsElement">

  <xs:complexContent>

   <xs:extension base="ifc:IfcRelDecomposes">

    <xs:sequence>

     <xs:element name="RelatedOpeningElement" type="ifc:IfcFeatureElementSubtraction" nillable="true"/>

    </xs:sequence>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcRelVoidsElement

 SUBTYPE OF (IfcRelDecomposes);

  RelatingBuildingElement : IfcElement;

  RelatedOpeningElement : IfcFeatureElementSubtraction;

END_ENTITY;

 EXPRESS-G diagram

IfcRelVoidsElement

Semantic definitions at the entity

Inherited definitions from supertypes

Definitions applying to General Usage

Examples

Formal representations

	Abzug / Subtraktion von Teil aus Element - Relation
	Rel Voids Element
	Relation de percement