IfcWallType

Item	Change	Description
IFC2x3 to IFC4
IfcWallType
OwnerHistory	MODIFIED	Instantiation changed to OPTIONAL.
ApplicableOccurrence	MODIFIED	Type changed from IfcLabel to IfcIdentifier.

Semantic definitions at the entity

Entity definition

The element type IfcWallType defines commonly shared information for occurrences of walls. The set of shared information may include:

common properties within shared property sets
common material information
common material layer definitions
common shape representations

NOTE It is illegal to share shape representations as representation maps for occurrences of IfcWallStandardcase.

It is used to define a wall specification (i.e. the specific product information, that is common to all occurrences of that product type). Wall types may be exchanged without being already assigned to occurrences.

NOTE The product representations are defined as representation maps (at the level of the supertype IfcTypeProduct, which gets assigned by an element occurrence instance through the IfcShapeRepresentation.Item[1] being an IfcMappedItem.

Occurrences of the IfcWallType within building models are represented by instances of IfcWallStandardCase if the IfcWallType has a single associated IfcMaterialLayerSet; otherwise they are represented by instances of IfcWall, or IfcWallElementedCase. Occurrences of the IfcWallType within structural analysis models are represented by instances of IfcStructuralSurfaceMember, or its applicable subtypes.

HISTORY New entity in IFC2x2.

Informal Propositions:

The material assignment, if provided using the IfcRelAssociatesMaterial relationship, shall not reference the IfcMaterialLayerSetUsage.

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
10	PredefinedType	IfcWallTypeEnum	[1:1]	Identifies the predefined types of a wall element from which the type required may be set.	X

Formal Propositions

Rule	Description
CorrectPredefinedType	The inherited attribute ElementType shall be provided, if the PredefinedType is set to USERDEFINED.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcRoot
1	GlobalId	IfcGloballyUniqueId	[1:1]	Assignment of a globally unique identifier within the entire software world.	X
2	OwnerHistory	IfcOwnerHistory	[0:1]	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 - either as addition, deletion or modification.	X
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.	X
4	Description	IfcText	[0:1]	Optional description, provided for exchanging informative comments.	X
IfcObjectDefinition
	HasAssignments	IfcRelAssigns @RelatedObjects	S[0:?]	Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups.	X
	Nests	IfcRelNests @RelatedObjects	S[0:1]	References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only).	X
	IsNestedBy	IfcRelNests @RelatingObject	S[0:?]	References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types).	X
	HasContext	IfcRelDeclares @RelatedDefinitions	S[0:1]	References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object.	X
	IsDecomposedBy	IfcRelAggregates @RelatingObject	S[0:?]	References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts).	X
	Decomposes	IfcRelAggregates @RelatedObjects	S[0:1]	References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only).	X
	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.	X
IfcTypeObject
5	ApplicableOccurrence	IfcIdentifier	[0:1]	The attribute optionally defines the data type of the occurrence object, to which the assigned type object can relate. If not present, no instruction is given to which occurrence object the type object is applicable. The following conventions are used: The IFC entity name of the applicable occurrence using the IFC naming convention, CamelCase with IFC prefix It can be optionally followed by the predefined type after the separator "/" (forward slash), using uppercase If one type object is applicable to many occurrence objects, then those occurrence object names should be separate by comma "," forming a comma separated string. EXAMPLE Refering to a furniture as applicable occurrence entity would be expressed as 'IfcFurnishingElement', refering to a brace as applicable entity would be expressed as 'IfcMember/BRACE', refering to a wall and wall standard case would be expressed as 'IfcWall, IfcWallStandardCase'.	X
6	HasPropertySets	IfcPropertySetDefinition	S[1:?]	Set ~~list~~ of unique property sets, that are associated with the object type and are common to all object occurrences referring to this object type.	X
	Types	IfcRelDefinesByType @RelatingType	S[0:1]	Reference to the relationship IfcRelDefinedByType and thus to those occurrence objects, which are defined by this type.	X
IfcTypeProduct
7	RepresentationMaps	IfcRepresentationMap	~L[1:?]	List of unique representation maps. Each representation map describes a block definition of the shape of the product style. By providing more than one representation map, a multi-view block definition can be given.	X
8	Tag	IfcLabel	[0:1]	The tag (or label) identifier at the particular type of a product, e.g. the article number (like the EAN). It is the identifier at the specific level.	X
	ReferencedBy	IfcRelAssignsToProduct @RelatingProduct	S[0:?]	Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product type.	X
IfcElementType
9	ElementType	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.	X
IfcBuildingElementType
IfcWallType
10	PredefinedType	IfcWallTypeEnum	[1:1]	Identifies the predefined types of a wall element from which the type required may be set.	X

Definitions applying to Common Use Definitions

Instance diagram

Concept usage

Material Layer Set

The Material Layer Set concept applies to this entity.

Figure 252 illustrates wall type material layer set.

Figure 252 — Wall type material layer set

The material of the IfcWallType is defined by the IfcMaterialLayerSet or as fall back by IfcMaterial and attached by the IfcRelAssociatesMaterial.RelatingMaterial. It is accessible by the inverse HasAssociations relationship.

NOTE It is illegal to assign an IfcMaterial to an IfcWallType, if there is at least one occurrences. of IfcWallStandardCase for this type.

The shared material layer set definition is defined by assigning an IfcMaterialLayerSet (see material use definition above). The IfcMaterialLayer refers to one or several of IfcMaterialLayer that is the common for all wall occurrence, if used. It is only applicable if the IfcWallType has only occurrences of type IfcWallStandardCase (see definition of IfcWallStandardCase for further information).

NOTE Since each individual instance of IfcWallStandardCase defines its own IfcMaterialLayerSetUsage including the offset from the wall axis, the same IfcWallType can be used independently of the axis alignment of its occurrences.

Type Body Geometry

The Type Body Geometry concept applies to this entity.

Concept inheritance

#	Concept	Model View
IfcRoot
	Software Identity	Common Use Definitions
	Revision Control	Common Use Definitions
IfcTypeProduct
	Product Type Shape	Common Use Definitions
IfcWallType
	Material Layer Set	Common Use Definitions
	Type Body Geometry	Common Use Definitions

Examples

Formal representations

XSD Specification

 <xs:element name="IfcWallType" type="ifc:IfcWallType" substitutionGroup="ifc:IfcBuildingElementType" nillable="true"/>

 <xs:complexType name="IfcWallType">

  <xs:complexContent>

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

    <xs:attribute name="PredefinedType" type="ifc:IfcWallTypeEnum" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcWallType

 SUBTYPE OF (IfcBuildingElementType);

  PredefinedType : IfcWallTypeEnum;

 WHERE

  CorrectPredefinedType : (PredefinedType <> IfcWallTypeEnum.USERDEFINED) OR
((PredefinedType = IfcWallTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcElementType.ElementType));
END_ENTITY;

 EXPRESS-G diagram

Link to this page

	Wand - Typ
	Wall Type
	Type de mur