Natural language names
 | Öffnung |
 | Opening Element |
 | Ouverture |
| Öffnung |
| Opening Element |
| Ouverture |
| Item | SPF | XML | Change | Description | IFC2x3 to IFC4 |
|---|---|---|---|---|
| IfcOpeningElement | ||||
| OwnerHistory | MODIFIED | Instantiation changed to OPTIONAL. | ||
| PredefinedType | ADDED | IFC4 Addendum 1 | ||
| IfcOpeningElement | ||||
| HasCoverings | ADDED |
The opening element stands for opening, recess or chase, all reflecting voids. It represents a void within any element that has physical manifestation. Openings can be inserted into walls, slabs, beams, columns, or other elements.
The IFC specification provides two entities for opening elements:
NOTE View definitions or implementer agreements may restrict the types of elements which can be voided by an IfcOpeningElement or IfcOpeningStandardCase
There are two different types of opening elements:
The attribute PredefinedType should be used to capture the differences,
An IfcOpeningElement has to be inserted into an IfcElement by using the IfcRelVoidsElement relationship. The relationship implies a Boolean subtraction operation between the volume of the voided element and the volume of the opening. It may be filled by an IfcDoor, IfcWindow, or another filling element by using the relationship IfcRelFillsElements.
The IfcOpeningElement shall not participate in the containment relationship, i.e. it is not linked directly to the spatial structure of the project. It has a mandatory VoidsElements inverse relationship pointing to the IfcElement that is contained in the spatial structure.
NOTE See IfcRelVoidsElement for a diagram on how to apply spatial containment and the voiding relationship.
HISTORY New entity in IFC1.0
IFC2x CHANGE The intermediate ABSTRACT supertypes IfcFeatureElement and IfcFeatureSubtraction have been added.
IFC4 CHANGE The attribute PredefinedType has been added at the end of attribute list. It should be used instead of the inherited attribute ObjectType from now on.
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| 9 | PredefinedType | IfcOpeningElementTypeEnum | [0:1] | Predefined generic type for an opening that is specified in an enumeration. There may be a property set given specificly for the predefined types. | X |
| HasFillings | IfcRelFillsElement @RelatingOpeningElement | S[0:?] | Reference to the Filling Relationship that is used to assign Elements as Fillings for this Opening Element. The Opening Element can be filled with zero-to-many Elements. | X |
| # | 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 | |
| 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.
| X |
| IsDeclaredBy | IfcRelDefinesByObject @RelatedObjects | S[0:1] | Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes. | X | |
| Declares | IfcRelDefinesByObject @RelatingObject | S[0:?] | Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes. | X | |
| IsTypedBy | IfcRelDefinesByType @RelatedObjects | S[0:1] | Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type. | X | |
| IsDefinedBy | IfcRelDefinesByProperties @RelatedObjects | S[0:?] | Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object. | X | |
| 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. | X |
| 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. | 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. | X | |
| IfcElement | |||||
| 8 | Tag | IfcIdentifier | [0:1] | The tag (or label) identifier at the particular instance of a product, e.g. the serial number, or the position number. It is the identifier at the occurrence level. | X |
| FillsVoids | IfcRelFillsElement @RelatedBuildingElement | S[0:1] | Reference to the IfcRelFillsElement Relationship that puts the element as a filling into the opening created within another element. | X | |
| 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. | X | |
| IsInterferedByElements | IfcRelInterferesElements @RelatedElement | S[0:?] | Reference to the interference relationship to indicate the element that is interfered. The relationship, if provided, indicates that this element has an interference with one or many other elements.
NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements. | X | |
| InterferesElements | IfcRelInterferesElements @RelatingElement | S[0:?] | Reference to the interference relationship to indicate the element that interferes. The relationship, if provided, indicates that this element has an interference with one or many other elements.
NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements. | X | |
| HasProjections | IfcRelProjectsElement @RelatingElement | S[0:?] | Projection relationship that adds a feature (using a Boolean union) to the IfcBuildingElement. | X | |
| ReferencedInStructures | IfcRelReferencedInSpatialStructure @RelatedElements | S[0:?] | Reference relationship to the spatial structure element, to which the element is additionally associated. This relationship may not be hierarchical, an element may be referenced by zero, one or many spatial structure elements. | X | |
| HasOpenings | IfcRelVoidsElement @RelatingBuildingElement | S[0:?] | Reference to the IfcRelVoidsElement relationship that creates an opening in an element. An element can incorporate zero-to-many openings. For each opening, that voids the element, a new relationship IfcRelVoidsElement is generated. | X | |
| IsConnectionRealization | IfcRelConnectsWithRealizingElements @RealizingElements | S[0:?] | Reference to the connection relationship with realizing element. The relationship, if provided, assigns this element as the realizing element to the connection, which provides the physical manifestation of the connection relationship. | X | |
| ProvidesBoundaries | IfcRelSpaceBoundary @RelatedBuildingElement | S[0:?] | Reference to space boundaries by virtue of the objectified relationship IfcRelSpaceBoundary. It defines the concept of an element bounding spaces. | X | |
| 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. | X | |
| ContainedInStructure | IfcRelContainedInSpatialStructure @RelatedElements | S[0:1] | Containment relationship to the spatial structure element, to which the element is primarily associated. This containment relationship has to be hierachical, i.e. an element may only be assigned directly to zero or one spatial structure. | X | |
| HasCoverings | IfcRelCoversBldgElements @RelatingBuildingElement | S[0:?] | Reference to IfcCovering by virtue of the objectified relationship IfcRelCoversBldgElement. It defines the concept of an element having coverings associated. | X | |
| IfcFeatureElement | |||||
| IfcFeatureElementSubtraction | |||||
| VoidsElements | IfcRelVoidsElement @RelatedOpeningElement | [1:1] | Reference to the Voids Relationship that uses this Opening Element to create a void within an Element. The Opening Element can only be used to create a single void within a single Element. | X | |
| IfcOpeningElement | |||||
| 9 | PredefinedType | IfcOpeningElementTypeEnum | [0:1] | Predefined generic type for an opening that is specified in an enumeration. There may be a property set given specificly for the predefined types. | X |
| HasFillings | IfcRelFillsElement @RelatingOpeningElement | S[0:?] | Reference to the Filling Relationship that is used to assign Elements as Fillings for this Opening Element. The Opening Element can be filled with zero-to-many Elements. | X | |
Property Sets for Objects
The Property Sets for Objects concept applies to this entity as shown in Table 54.
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Table 54 — IfcOpeningElement Property Sets for Objects |
Quantity Sets
The Quantity Sets concept applies to this entity as shown in Table 55.
| ||
Table 55 — IfcOpeningElement Quantity Sets |
Element Filling
The Element Filling concept applies to this entity.
Product Local Placement
The Product Local Placement concept applies to this entity as shown in Table 56.
| ||||||||||||
Table 56 — IfcOpeningElement Product Local Placement |
The local placement for IfcOpeningElement 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.
Body Geometry
The Body Geometry concept applies to this entity as shown in Table 57.
| ||||
Table 57 — IfcOpeningElement Body Geometry |
Currently, the 'Body', and 'Box' representations are supported. The 'Box' representation includes the representation type 'BoundingBox' and is explained at IfcFeatureElement.
The 'Body' representation of IfcOpeningElement can be represented using the representation types 'SweptSolid', and 'Brep'. The representation type 'Brep' is explained at IfcFeatureElement
Swept Solid Representation Type with Horizontal Extrusion
The 'SweptSolid' geometric representation of IfcOpeningElement, using horizontal extrusion direction (for walls), is defined using the swept area solid geometry. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:
The following additional constraints apply to the swept solid representation:
NOTE In case of non-parallel jambs, the shape representation shall be a 'SweptSolid' representation with vertical extrusion.
Figure 151 illustrates an opening with horizontal extrusion.
NOTE The local placement directions for the IfcOpeningElement are only given as an example, other directions are valid as well.
 |
|
Figure 151 — Opening with full extrusion |
Figure 152 illustrates an opening for a recess.
NOTE The local placement directions for the IfcOpeningElement are only given as an example, other directions are valid as well.
NOTE Rectangles are now defined centric, the placement location has to be set:
 |
|
Figure 152 — Opening with recess extrusion |
Swept Solid Representation with Vertical Extrusion
The 'SweptSolid' geometric representation of IfcOpeningElement, using vertical extrusion direction (for walls), is defined using the swept area solid geometry, however the extrusion direction may be vertical, i.e. in case of a wall opening, the extrusion would be in the direction of the wall height. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:
The following additional constraints apply to the swept solid representation:
Vertical extrusions shall be used when an opening or recess has a non rectangular foot print geometry that does not change along the height of the opening or recess.
Figure 153 shows a vertical extrusion with multiple extrusion bodies for the opening. Each extrusion body has a different extrusion lenght.
NOTE The local placement directions for the IfcOpeningElement are only given as an example, other directions are valid as well.
 |
Figure 153 — Opening with multiple extrusions |
| # | Concept | Model View |
|---|---|---|
| IfcRoot | ||
| Software Identity | Common Use Definitions | |
| Revision Control | Common Use Definitions | |
| IfcObject | ||
| Object Occurrence Predefined Type | Common Use Definitions | |
| IfcElement | ||
| Box Geometry | Common Use Definitions | |
| FootPrint Geometry | Common Use Definitions | |
| Body SurfaceOrSolidModel Geometry | Common Use Definitions | |
| Body SurfaceModel Geometry | Common Use Definitions | |
| Body Tessellation Geometry | Common Use Definitions | |
| Body Brep Geometry | Common Use Definitions | |
| Body AdvancedBrep Geometry | Common Use Definitions | |
| Body CSG Geometry | Common Use Definitions | |
| Mapped Geometry | Common Use Definitions | |
| Mesh Geometry | Common Use Definitions | |
| IfcFeatureElement | ||
| Spatial Containment | Common Use Definitions | |
| IfcOpeningElement | ||
| Property Sets for Objects | Common Use Definitions | |
| Quantity Sets | Common Use Definitions | |
| Element Filling | Common Use Definitions | |
| Product Local Placement | Common Use Definitions | |
| Body Geometry | Common Use Definitions | |
Instance diagram <xs:element name="IfcOpeningElement" type="ifc:IfcOpeningElement" substitutionGroup="ifc:IfcFeatureElementSubtraction" nillable="true"/>
<xs:complexType name="IfcOpeningElement">
<xs:complexContent>
<xs:extension base="ifc:IfcFeatureElementSubtraction">
<xs:attribute name="PredefinedType" type="ifc:IfcOpeningElementTypeEnum" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
ENTITY IfcOpeningElement
SUPERTYPE OF(IfcOpeningStandardCase)
SUBTYPE OF (IfcFeatureElementSubtraction);
PredefinedType : OPTIONAL IfcOpeningElementTypeEnum;
INVERSE
HasFillings : SET OF IfcRelFillsElement FOR RelatingOpeningElement;
END_ENTITY;
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