IFC 4.3.x development

6.1.3.56 IfcWindow

Change log

IFC4

additionsattributes PartitioningType
additionsattributes PredefinedType
additionsattributes UserDefinedPartitioningType
additionswhere_rulesCorrectStyleAssigned

IFC4X1

additionswhere_rulesCorrectStyleAssigned
deletionswhere_rulesCorrectStyleAssigned

IFC4X2

additionswhere_rulesCorrectStyleAssigned
deletionswhere_rulesCorrectStyleAssigned

IFC4X3_RC3

additions where_rulesCorrectPredefinedType
additions where_rulesCorrectStyleAssigned
additions where_rulesCorrectTypeAssigned
deletions where_rulesCorrectStyleAssigned
modificationssupertype Changed from IfcBuildingElement to IfcBuiltElement

6.1.3.56.1 Semantic definitions at the entity

The window is a building element that is predominately used to provide natural light and fresh air. It includes vertical opening but also horizontal opening such as skylights or light domes. It includes constructions with swinging, pivoting, sliding, or revolving panels and fixed panels. A window consists of a lining and one or several panels.

NOTE  Definition according to ISO 6707-1
Construction for closing a vertical or near vertical opening in a wall or pitched roof that will admit light and may admit fresh air.

The IfcWindow defines a particular occurrence of a window inserted in the spatial context of a project. A window can:

NOTE  View definitions or implementer agreements may restrict the relationship to only include one window (or door) into one opening.

There are two entities for window occurrences:

  • IfcWindowStandardCase used for all occurrences of windows, that have a 'Profile' shape representation defined to which a set of shape parameters for lining and framing properties apply. Additionally it requires the provision of an IfcWindowType that references one IfcWindowLiningProperties and on to many IfcWindowPanelProperties.
  • IfcWindow used for all other occurrences of windows, particularly for windows having only 'Brep', or 'SurfaceModel' geometry without applying shape parameters.

The actual parameter of the window and/or its shape is defined at the IfcWindow as the occurrence definition (or project instance), or by the IfcWindowType as the specific definition (or project type). The following parameters are given:

  • at the IfcWindow or IfcWindowStandardCase for occurrence specific parameters. The IfcWindow specifies:
    • the window width and height
    • the window opening direction (by the y-axis of the ObjectPlacement)
  • at the IfcWindowType to which the IfcWindow is related by the inverse relationship IsDefinedBy pointing to IfcRelDefinesByType, for type parameters common to all occurrences of the same type.
    • the partitioning type (single panel, double panel, tripel panel, more panels)
    • the operation type (swing, tilt and turn, pivot revolve, fixed case ment, etc.)
    • the window panel hinge side (by using two different styles for right and left opening windows)
    • the construction material type
    • the particular attributes for the lining by the IfcWindowLiningProperties
    • the particular attributes for the panels by the  IfcWindowPanelProperties

HISTORY  New entity in IFC1.0.

IFC4 CHANGE  The attributes PredefinedType and OperationType are added, the applicable type object has been changed to IfcDoorType.

Parameteric Representation using parameters at IfcWindowType

The parameters, which define the shape of the IfcWindow, are given at the IfcWindowType and the property sets, which are included in the IfcWindowType. The IfcWindow only defines the local placement. The overall size of the IfcWindow to be used to apply the lining or panel parameter provided by the IfcWindowType is determined by the IfcShapeRepresentation with the RepresentationIdentifier = 'Profile'. Only in case of an IfcWindow inserted into an IfcOpeningElement using the IfcRelFillsElement relatioship, having a horizontal extrusion (along the y-axis of the IfcDoor), the overall size is determined by the extrusion profile of the IfcOpeningElement.

Figure 1 illustrates the insertion of a window into the IfcOpeningElement by creating an instance of IfcWindow with PartitioningType = DoublePanelHorizontal. The parameters OverallHeight and OverallWidth show the extent of the window in the positive Z and X axis of the local placement of the window. The lining and the transom are created by the given parameters.

"window 1"

Figure 2 illustrates the final window (DoublePanelHorizontal) with first panel having PanelPosition = TOP, OperationType = BOTTOMHUNG and second panel having PanelPosition = BOTTOM and OperationType = TILTANDTURNLEFTHAND.

"window 2"

Window opening operation by window type

The parameters that defines the shape of the IfcWindow, are given at the IfcWindowType and the property sets, which are included in the IfcWindowType. The IfcWindow only defines the local placement which determines the opening direction of the window. The overall layout of the IfcWindow is determined by its IfcWindowType.PartitioningType. Each window panel has its own operation type, provided by IfcWindowPanelProperties.OperationType. All window panels are assumed to open into the same direction (if relevant for the particular window panel operation. The hindge side (whether a window opens to the left or to the right) is determined by the IfcWindowPanelProperties.OperationType.

NOTE   There are different conventions in different countries on how to show the symbolic presentation of the window panel operation (the "triangles"). Either as seen from the exterior, or from the interior side. The following figures show the symbolics from the exterior side (the convention as used predominately in Europe).

Figure 3 illustrates window operation types.

fig 1

The window panel (for side hung windows) opens always into the direction of the positive Y axis of the local placement. The determination of whether the window opens to the left or to the right is done at IfcWindowPanelProperties.OperationType. Here it is a left side opening window given by OperationType = SideHungLeftHand.

fig 2

If the window should open to the other side, then the local placement has to be changed. It is still a left hung window, given by IfcWindowPanelProperties.OperationType = SideHungLeftHand.

fig 3

If the window panel (for side hung windows) opens to the right, a separate window panel style needs to be used (here IfcWindowPanelProperties.OperationType = SideHungRightHand) and it always opens into the direction of the positive Y axis of the local placement. 

fig 4

If the window should open to the other side, then the local placement has to be changed. It is still a right hung window, given by IfcWindowPanelProperties.OperationTypeSideHungRightHand.

.

Figure 3 — Window operations

6.1.3.56.1 Attributes

# Attribute Type Description
IfcRoot
1 GlobalId IfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world.
2 OwnerHistory OPTIONAL 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.


3 Name OPTIONAL 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.
4 Description OPTIONAL IfcText Optional description, provided for exchanging informative comments.
IfcObjectDefinition
HasAssignments SET [0:?] OF IfcRelAssigns FOR RelatedObjects 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.
Nests SET [0:1] OF IfcRelNests FOR RelatedObjects 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).

> IFC4 CHANGE  The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
IsNestedBy SET [0:?] OF IfcRelNests FOR RelatingObject 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).

> IFC4 CHANGE  The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
HasContext SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions 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.

> IFC4 CHANGE  The inverse attribute datatype has been added.
IsDecomposedBy SET [0:?] OF IfcRelAggregates FOR RelatingObject 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).

> IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
Decomposes SET [0:1] OF IfcRelAggregates FOR RelatedObjects 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).

> IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
HasAssociations SET [0:?] OF IfcRelAssociates FOR RelatedObjects 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 OPTIONAL IfcLabel 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.
IsDeclaredBy SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects 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.

> IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
Declares SET [0:?] OF IfcRelDefinesByObject FOR RelatingObject 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.

> IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
IsTypedBy SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects 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.

> IFC4 CHANGE  New inverse relationship, the link to IfcRelDefinesByType had previously be included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
IsDefinedBy SET [0:?] OF IfcRelDefinesByProperties FOR RelatedObjects 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.

> IFC4 CHANGE  The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.
IfcProduct
6 ObjectPlacement OPTIONAL IfcObjectPlacement 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 IfcProductDefinitionShape 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.
ReferencedBy SET [0:?] OF IfcRelAssignsToProduct FOR RelatingProduct Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product.
PositionedRelativeTo SET [0:1] OF IfcRelPositions FOR RelatedProducts
ReferencedInStructures SET [0:?] OF IfcRelReferencedInSpatialStructure FOR RelatedElements
IfcElement
8 Tag OPTIONAL IfcIdentifier 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.
FillsVoids SET [0:1] OF IfcRelFillsElement FOR RelatedBuildingElement Reference to the IfcRelFillsElement Relationship that puts the element as a filling into the opening created within another element.
ConnectedTo SET [0:?] OF IfcRelConnectsElements FOR RelatingElement Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to.
IsInterferedByElements SET [0:?] OF IfcRelInterferesElements FOR RelatedElement 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.

> IFC4 CHANGE New inverse relationship.
InterferesElements SET [0:?] OF IfcRelInterferesElements FOR RelatingElement 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.

> IFC4 CHANGE New inverse relationship.
HasProjections SET [0:?] OF IfcRelProjectsElement FOR RelatingElement Projection relationship that adds a feature (using a Boolean union) to the IfcBuildingElement.
HasOpenings SET [0:?] OF IfcRelVoidsElement FOR RelatingBuildingElement 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.
IsConnectionRealization SET [0:?] OF IfcRelConnectsWithRealizingElements FOR RealizingElementsReference 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.
ProvidesBoundaries SET [0:?] OF IfcRelSpaceBoundary FOR RelatedBuildingElement Reference to space boundaries by virtue of the objectified relationship IfcRelSpaceBoundary. It defines the concept of an element bounding spaces.
ConnectedFrom SET [0:?] OF IfcRelConnectsElements FOR RelatedElement Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element.
ContainedInStructure SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements 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.
HasCoverings SET [0:?] OF IfcRelCoversBldgElements FOR RelatingBuildingElement Reference to IfcCovering by virtue of the objectified relationship IfcRelCoversBldgElement. It defines the concept of an element having coverings associated.
HasSurfaceFeatures INVALID Reference to the IfcRelAdheresToElement relationship that adheres a IfcSurfaceFeature to an element. An element can incorporate zero-to-many surface features in one relationship.
IfcBuiltElement
IfcWindow
9 OverallHeight OPTIONAL IfcPositiveLengthMeasure Overall measure of the height, it reflects the Z Dimension of a bounding box, enclosing the window opening. If omitted, the OverallHeight should be taken from the geometric representation of the IfcOpening in which the window is inserted.

> NOTE  The body of the window might be taller then the window opening (for example in cases where the window lining includes a casing). In these cases the OverallHeight shall still be given as the window opening height, and not as the total height of the window lining.
10 OverallWidth OPTIONAL IfcPositiveLengthMeasure Overall measure of the width, it reflects the X Dimension of a bounding box, enclosing the window opening. If omitted, the OverallWidth should be taken from the geometric representation of the IfcOpening in which the window is inserted.

> NOTE  The body of the window might be wider then the window opening (for example in cases where the window lining includes a casing). In these cases the OverallWidth shall still be given as the window opening width, and not as the total width of the window lining.
11 PredefinedType OPTIONAL IfcWindowTypeEnum Predefined generic type for a window that is specified in an enumeration. There may be a property set given specificly for the predefined types.

> NOTE  The PredefinedType shall only be used, if no IfcWindowType is assigned, providing its own _IfcWindowType.PredefinedType_.

> IFC4 CHANGE The attribute has been added at the end of the entity definition.
12 PartitioningType OPTIONAL IfcWindowTypePartitioningEnum Type defining the general layout of the window in terms of the partitioning of panels.

> NOTE  The PartitioningType shall only be used, if no type object IfcWindowType is assigned, providing its own _IfcWindowType.PartitioningType_.

> IFC4 CHANGE The attribute has been added at the end of the entity definition.
13 UserDefinedPartitioningTypeOPTIONAL IfcLabel Designator for the user defined partitioning type, shall only be provided, if the value of PartitioningType is set to USERDEFINED.

6.1.3.56.2 Entity inheritance

dot_inheritance IfcWindowStandardCase IfcWindowStandardCase IfcWindow IfcWindow IfcWindowStandardCase->IfcWindow IfcBuiltElement IfcBuiltElement IfcWindow->IfcBuiltElement IfcBuiltElement_children 29 more... IfcBuiltElement_children->IfcBuiltElement IfcElement IfcElement IfcBuiltElement->IfcElement IfcElement_children 10 more... IfcElement_children->IfcElement IfcProduct IfcProduct IfcElement->IfcProduct IfcProduct_children 8 more... IfcProduct_children->IfcProduct IfcObject IfcObject IfcProduct->IfcObject IfcObject_children 5 more... IfcObject_children->IfcObject IfcObjectDefinition IfcObjectDefinition IfcObject->IfcObjectDefinition IfcContext IfcContext IfcContext->IfcObjectDefinition IfcRoot IfcRoot IfcObjectDefinition->IfcRoot IfcTypeObject IfcTypeObject IfcTypeObject->IfcObjectDefinition IfcPropertyDefinition IfcPropertyDefinition IfcPropertyDefinition->IfcRoot IfcRelationship IfcRelationship IfcRelationship->IfcRoot

6.1.3.56.3 Definitions applying to General Usage

6.1.3.56.3.1 Body AdvancedBrep Geometry

An IfcElement (so far no further constraints are defined at the level of its subtypes or by view definitions) may be represented as a single or multiple boundary representation models, which include advanced surfaces, usually refered to as NURBS surfaces. The 'AdvancedBrep' representation allows for the representation of complex free-form element shape.

NOTE  View definitions or implementer agreements may restrict or disallow the use of 'AdvancedBrep' geometry.

6.1.3.56.3.2 Body Brep Geometry

Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented as a single or multiple Boundary Representation models (which are restricted to be faceted Brep's with or without voids). The Brep representation allows for the representation of complex element shape.

 

Brep representation
EXAMPLE  As shown in Figure 150, the Brep representation is given by an IfcShapeRepresentation, which includes one or more items, all of type IfcFacetedBrep. In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape.

Figure 150 — Building element body boundary representation

 

6.1.3.56.3.3 Body CSG Geometry

Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented a CSG primitive or CSG tree. The CSG representation allows for the representation of complex element shape.

NOTE  View definitions or implementer agreements may restrict or disallow the use of 'CSG' geometry.

6.1.3.56.3.4 Body SurfaceModel Geometry

Any IfcElement (so far 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 surface models. It may also include tessellated models.

 

surface model
EXAMPLE  As shown in Figure 149, the surface model representation is given by an IfcShapeRepresentation, which includes a single item which is either an IfcShellBasedSurfaceModel, or an IfcFaceBasedSurfaceModel. In some cases it may also be useful to expose a simple representation as a bounding box representation of the same complex shape.

Figure 149 — Element surface model representation

 

6.1.3.56.3.5 Body SurfaceOrSolidModel Geometry

Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented as a mixed representation, including surface and solid models.

6.1.3.56.3.6 Body Tessellation Geometry

Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented as a single or multiple tessellated surface models, in particular triangulated surface models.

6.1.3.56.3.7 Box Geometry

bounding box
EXAMPLE  Any IfcElement may be represented by a bounding box, which shows the maximum extend of the body within the object coordinate system established by the IfcObjectPlacement. As shown in Figure 148, the bounding box representation is given by an IfcShapeRepresentation that includes a single item, an IfcBoundingBox.

Figure 148 — Building element box representation

 

6.1.3.56.3.8 Classification Association

Any object occurrence or object type can have a reference to a specific classification reference, i.e. to a particular facet within a classification system.

6.1.3.56.3.9 CoG Geometry

The 'CoG', Center of Gravity, shape representation is used as a means to verify the correct import by comparing the CoG of the imported geometry with the explicily provided CoG created during export.

6.1.3.56.3.10 Element Projecting

6.1.3.56.3.11 Element Voiding

6.1.3.56.3.12 FootPrint Geometry

Identifier Type
'FootPrint' 'GeometricCurveSet'
'FootPrint' 'Annotation2D'

6.1.3.56.3.13 Identity

IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.

6.1.3.56.3.14 Mapped Geometry

Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented using the 'MappedRepresentation'. This shall be supported as it allows for reusing the geometry definition of a type at all occurrences of the same type. The results are more compact data sets.

The same constraints, as given for 'SurfaceOrSolidModel', 'SurfaceModel', 'Tessellation', 'Brep', and 'AdvancedBrep' geometric representation, shall apply to the IfcRepresentationMap.

6.1.3.56.3.15 Material Constituent Set

The material of the IfcWindow is defined by the IfcMaterialConstituentSet or as fall back by IfcMaterial and attached by the IfcRelAssociatesMaterial. It is accessible by the inverse HasAssociations relationship. The following keywords for IfcMaterialConstituentSet.MaterialConstituents[n].Name shall be used:

  • 'Lining' - to indicate that the material constituent applies to to the window lining
  • 'Framing' - to indicate that the material constituent applies to to the window panels, if not provided, the 'Lining' material information applied to panels as well
  • 'Glazing' - to indicate that the material constituent applies to to the glazing part

If the fall back single IfcMaterial is referenced, it applies to the lining and framing of the window.

6.1.3.56.3.16 Object Predefined Type

6.1.3.56.3.17 Object Typing

RelatingType
'IfcWindowType'

6.1.3.56.3.18 Object User Identity

An attribute Name and optionally Description can be used for all subypes of IfcObject. For those subtypes, that have an object type definition, such as ifcBeam - IfcBeamType, the common Name and optionally Description is associated with the object type.

6.1.3.56.3.19 Product Geometric Representation

The geometric representation of any IfcProduct is provided by the IfcProductDefinitionShape allowing multiple geometric representations. It uses the Product Placement concept utilizing IfcLocalPlacement to establish an object coordinate system, within all geometric representations are founded.

NOTE  A detailed specification of how to apply the local placement and which shape representaions are applicable is provided at the level of subtypes of IfcProduct and is further determined by the model view definition and implementer agreements.

6.1.3.56.3.20 Product Local Placement

The following restriction is imposed:

  1. The PlacementRelTo relationship of IfcLocalPlacement shall point to the local placement of the same element (if given), in which the IfcWindow is used as a filling (normally an IfcOpeningElement), as provided by the IfcRelFillsElement relationship.
  2. If the IfcWindow is not inserted into an IfcOpeningElement, then the PlacementRelTo relationship of IfcLocalPlacement shall point (if given) to the local placement of the same IfcSpatialStructureElement that is used in the ContainedInStructure inverse attribute or to a referenced spatial structure element at a higher level.
  3. If the relative placement is not used, the absolute placement is defined within the world coordinate system.
NOTE  The product placement is used to determine the opening direction of the window.
HasPlacement
'IfcLocalPlacement'
'IfcLocalPlacement'

6.1.3.56.3.21 Product Placement

The Product Placement establishes the object coordinate system and is required, if a geometric shape representation is provided for this product.

6.1.3.56.3.22 Profile 3D Geometry

The window profile is represented by a three-dimensional closed curve within a particular shape representation. The profile is used to apply the parameter of the parametric window representation. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

  • RepresentationIdentifier : 'Profile'
  • RepresentationType : 'Curve3D', only a single closed curve shall be contained in the set of IfcShapeRepresentation.Items.

A 'Profile' representation has to be provided if:

  • a parametric representation shall be applied to the window AND
    • the window is 'free standing', or
    • the opening into which the window is inserted is not extruded horizontally (i.e. where the opening profile does not match the window profile)

The following additional constraints apply to the 'Profile' representation type:

  • Curve: being an IfcPolyline defining a rectangle.
  • Position: The curve shall lie in the xz plane of the object placement coordinate (the y coordinate values of the IfcCartesianPoint's shall be 0.).

As shown in Figure 298, the profile defines the outer boundary to which the window lining parameters relate as:

  • IfcWindowLiningProperties.LiningDepth starting at distance defined by LiningOffset going into the positive y direction.
  • IfcWindowLiningProperties.LiningThickness offset into the inner side of the rectangle.
  • IfcWindowLiningProperties.LiningOffset distance along the positive y direction to where the LiningDepth applies.
  • IfcWindowLiningProperties.FirstTransomOffset starting at the bottom edge of the rectangle (along local x axis) into the inner side of the rectangle, distance provided as percentage of overall height. Distance to the centre line of the transom. SecondTransomOffset defined accordingly.
  • IfcWindowLiningProperties.FirstMullionOffset starting at the left edge of the rectangle (along local z-axis) into the inner side of the rectangle, distance provided as percentage of overall width. Distance to the centre line of the mullion. SecondMullionOffset defined accordingly.
standard window

Figure 298 — Window profile

6.1.3.56.3.23 Property Sets for Objects

PsetName
'Pset_WindowCommon'
'Pset_EnvironmentalImpactIndicators'
'Pset_EnvironmentalImpactValues'
'Pset_Condition'
'Pset_ManufacturerOccurrence'
'Pset_ManufacturerTypeInformation'
'Pset_ServiceLife'
'Pset_Warranty'

6.1.3.56.3.24 Property Sets with Override

Any object occurrence can hold property sets, either directly at the object occurrence as element specific property sets, or at the object type, as type property sets. In this case, the properties that are provided to the object occurrence are the combinations of element specific and type properties. In case, that the same property (within the same property set, is defined both, in occurrence and type properties, the property value of the occurrence property overrides the property value of the type property.

6.1.3.56.3.25 Quantity Sets

QsetName
'Qto_WindowBaseQuantities'

6.1.3.56.3.26 Revision Control

Ownership, history, and merge state is captured using IfcOwnerHistory.

6.1.3.56.3.27 Spatial Containment

The IfcWindow, as any subtype of IfcBuildingElement, may participate alternatively in one of the two different containment relationships:

  • the Spatial Containment (defined here), or
  • the Element Composition.

The IfcWindow may also be connected to the IfcOpeningElement in which it is placed as a filler. In this case, the spatial containment relationship shall be provided, see Figure 297.

Containment
NOTE  The containment shall be defined independently of the filling relationship, that is, even if the IfcWindow is a filling of an opening established by IfcRelFillsElement, it is also contained in the spatial structure by an IfcRelContainedInSpatialStructure.

Figure 297 — Window spatial containment

 
RelatingStructure
'IfcBuildingStorey'

6.1.3.56.3.28 Window Attributes

The IfcWindowTypePartitioningEnum defines the general layout of the window type and its symbolic presentation. Depending on the enumerator, the appropriate instances of IfcWindowLiningProperties and IfcWindowPanelProperties are attached in the list of HasPropertySets. The IfcWindowTypePartitioningEnum mainly determines the way of partitioning the window into individual window panels and thereby number and position of window panels.

See IfcWindowTypePartitioningEnum for the correct usage of panel partitioning and IfcWindowPanelProperties for the opening symbols for different panel operation types.

6.1.3.56.4 Formal representations

ENTITY IfcWindow
 SUPERTYPE OF (ONEOF
	(IfcWindowStandardCase))
 SUBTYPE OF (IfcBuiltElement);
	OverallHeight : OPTIONAL IfcPositiveLengthMeasure;
	OverallWidth : OPTIONAL IfcPositiveLengthMeasure;
	PredefinedType : OPTIONAL IfcWindowTypeEnum;
	PartitioningType : OPTIONAL IfcWindowTypePartitioningEnum;
	UserDefinedPartitioningType : OPTIONAL IfcLabel;
 WHERE
	CorrectStyleAssigned : (SIZEOF(IsTypedBy) = 0) 
OR ('IFC4X3_DEV.IFCWINDOWTYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));
END_ENTITY;