#### IfcBuildingElementComponent

Natural language names

##### Semantic definitions at the entity

Entity definition

A building element component represents items included in building elements, which usually are not of interest from the overall building structure viewpoint. Contrary to accessories these components form a significant part of the building elements they belong to and usually have a vital and load carrying function within the structure. Typical examples of IfcBuildingElementComponents include different kinds of reinforcing elements, layers of sandwich wall panels, and plates as parts of structural members.

> HISTORY New entity in IFC Release 2x2

Geometry Use Definitions:

The geometric representation of IfcBuildingElementComponent is given by the IfcProductDefinitionShape, allowing multiple geometric representations. Included are:

Local Placement
The local placement for IfcBuildingElementComponent is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.

- The PlacementRelTo relationship of IfcLocalPlacement shall point (if given) to the local placement of the same IfcBuildingElement or IfcElementAssembly, which is used in the Decomposes inverse attribute, i.e. the local placement is defined relative to the local placement of the building element or element assembly in which the component is contained.
- If the relative placement is not used, the absolute placement is defined within the world coordinate system.

SurfaceModel Representation
Any IfcBuildingElementComponent (if no further constraints are defined at the level of its subtypes) may be represented as a single or multiple surface models, based on either shell or face based models. It is ensured by assigning the value 'SurfaceModel' to the RepresentationType attribute of IfcShapeRepresentation. In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape.

Brep Representation
Any IfcBuildingElementComponent (if no further constraints are defined at the level of its subtypes) may be represented as a single or multiple Boundary Representation elements (which are restricted to faceted Brep with or without voids). The Brep representation allows for the representation of complex element shape. It is ensured by assigning the value 'Brep' to the RepresentationType attribute of IfcShapeRepresentation. In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape.

MappedRepresentation
The mapped item, IfcMappedItem, should be used if appropriate as it allows for reusing the geometry definition of the equipment type at occurrences of the same equipment type. In this case the IfcShapeRepresentation.RepresentationType = 'MappedRepresentation' is used.

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description
--- | --- | --- | --- | ---
IfcRoot
1 | GlobalId | IfcGloballyUniqueId | [1:1] | Assignment of a globally unique identifier within the entire software world.
2 | OwnerHistory | IfcOwnerHistory | [1:1] | 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.
3 | Name | IfcLabel | [0:1] | 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.
4 | Description | - |  | This attribute is out of scope for this model view definition and shall not be set.
IfcObjectDefinition
| IsDecomposedBy | IfcRelDecomposes @RelatingObject | S[0:?] | Reference to the decomposition relationship, that allows this object to be the composition of other objects. An object can be decomposed by several other objects.
| Decomposes | IfcRelDecomposes @RelatedObjects | S[0:1] | References to the decomposition relationship, that allows this object to be a part of the decomposition. An object can only be part of a single decomposition (to allow hierarchical strutures only).
| HasAssociations | IfcRelAssociates @RelatedObjects | S[0:?] | Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification.
IfcObject
5 | ObjectType | IfcLabel | [0:1] | The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED.
| IsDefinedBy | IfcRelDefines @RelatedObjects | S[0:?] | Set of relationships to type or property (statically or dynamically defined) information that further define the object. In case of type information, the associated IfcTypeObject contains the specific information (or type, or style), that is common to all instances of IfcObject referring to the same type.
IfcProduct
6 | ObjectPlacement | IfcObjectPlacement | [0:1] | Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system.
7 | Representation | IfcProductRepresentation | [0:1] | Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement.
IfcElement
8 | Tag | - |  | This attribute is out of scope for this model view definition and shall not be set.
| ConnectedTo | IfcRelConnectsElements @RelatingElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to.
| HasOpenings | IfcRelVoidsElement @RelatingBuildingElement | S[0:?] | Reference to the Voids Relationship that creates an opening in an element. An element can incorporate zero-to-many openings.
| IsConnectionRealization | IfcRelConnectsWithRealizingElements @RealizingElements | S[0:?] | Reference to the connection relationship with realizing element. The relationship then refers to the realizing element which provides the physical manifestation of the connection relationship.
| ConnectedFrom | IfcRelConnectsElements @RelatedElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element.
| ContainedInStructure | IfcRelContainedInSpatialStructure @RelatedElements | S[0:1] | Containment relationship to the spatial structure element, to which the element is primarily associated.
IfcBuildingElement
IfcBuildingElementComponent

##### Definitions applying to AISC Model View

Instance diagram

Concept inheritance

# | Concept | Model View
--- | --- | ---
IfcBuildingElementComponent

##### Formal representations

XSD Specification
`<xs:element name="IfcBuildingElementComponent" type="ifc:IfcBuildingElementComponent" abstract="true" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>
<xs:complexType name="IfcBuildingElementComponent" abstract="true">
<xs:complexContent>
<xs:extension base="ifc:IfcBuildingElement"/>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`*)
ENTITY IfcBuildingElementComponent
SUBTYPE OF (IfcBuildingElement);
END_ENTITY;
(*

EXPRESS-G diagram

`

Inheritance Graph:

ENTITY IfcBuildingElementComponent
ENTITY IfcRoot
GlobalId : IfcGloballyUniqueId;
OwnerHistory : IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcStrippedOptional;
ENTITY IfcObjectDefinition
INVERSE
IsDecomposedBy : SET [0:?] OF IfcRelDecomposes FOR RelatingObject;
Decomposes : SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;
HasAssociations : SET [0:?] OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject
ObjectType : OPTIONAL IfcLabel;
INVERSE
IsDefinedBy : SET [0:?] OF IfcRelDefines FOR RelatedObjects;
ENTITY IfcProduct
ObjectPlacement : OPTIONAL IfcObjectPlacement;
Representation : OPTIONAL IfcProductRepresentation;
INVERSE
ENTITY IfcElement
Tag : OPTIONAL IfcStrippedOptional;
INVERSE
ConnectedTo : SET [0:?] OF IfcRelConnectsElements FOR RelatingElement;
HasOpenings : SET [0:?] OF IfcRelVoidsElement FOR RelatingBuildingElement;
IsConnectionRealization : SET [0:?] OF IfcRelConnectsWithRealizingElements FOR RealizingElements;
ConnectedFrom : SET [0:?] OF IfcRelConnectsElements FOR RelatedElement;
ContainedInStructure : SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements;
ENTITY IfcBuildingElement
ENTITY IfcBuildingElementComponent
END_ENTITY;

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