IFC 4.3.2.20241204 (IFC4X3_ADD2) under development

6.1.3.44 IfcWindow

6.1.3.44.1 Semantic definition

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. A window can:

There are two main representations for window occurrences:

  • IfcWindow entities that have a 3D rectangle 'Profile' shape representation defined. This profile can then be used to parametrically generate the geometry of a window. If not provided, the profile of the IfcOpeningElement can be used if the window fills an opening. The parameters are specified on the relating IfcWindowType that references IfcWindowLiningProperties and IfcWindowPanelProperties for each panel in the window;
  • IfcWindow entities that are not parametrically generated and have only 'Brep', or 'SurfaceModel' geometry.

In addition, an IfcWindow may commonly include a 'FootPrint' representation defining the 2D shape of the window and its swing.

  • the window width and height
  • the window opening direction (by the positive y-axis of the ObjectPlacement)

The IfcWindowType specifies parameters which are common to all of its occurrences of IfcWindow:

  • the partitioning type (single panel, double panel, triple panel, more panels)
  • the operation type (swing, tilt and turn, pivot revolve, fixed casement, etc.)
  • the window panel hinge side (by using two different styles for right and left opening windows)
  • the particular attributes for the lining by the IfcWindowLiningProperties
  • the particular attributes for the panels by the IfcWindowPanelProperties

6.1.3.44.2 Entity inheritance

6.1.3.44.3 Attributes

# Attribute Type Description
IfcRoot (4)
IfcObjectDefinition (7)
IfcObject (5)
IfcProduct (5)
IfcElement (13)
Click to show 34 hidden inherited attributes
IfcWindow (5)
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 IfcOpeningElement in which the window is inserted.

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 IfcOpeningElement in which the window is inserted.

11 PredefinedType OPTIONAL IfcWindowTypeEnum

Predefined generic type for a window that is specified in an enumeration. There may be a property set given specifically for the predefined types.

12 PartitioningType OPTIONAL IfcWindowTypePartitioningEnum

Type defining the general layout of the window in terms of the partitioning of panels.

13 UserDefinedPartitioningType OPTIONAL IfcLabel

Designator for the user defined partitioning type, shall only be provided, if the value of PartitioningType is set to USERDEFINED.

Table 6.1.3.44.L

6.1.3.44.4 Formal propositions

Name Description
CorrectPredefinedType

Either the PredefinedType attribute is unset (e.g. because an IfcWindowType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.

NOT(EXISTS(PredefinedType)) OR
(PredefinedType <> IfcWindowTypeEnum.USERDEFINED) OR
((PredefinedType = IfcWindowTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType))
CorrectTypeAssigned

Either there is no door type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcWindowType.

(SIZEOF(IsTypedBy) = 0) OR
('IFC4X3_DEV_54a9de1b.IFCWINDOWTYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType))
Table 6.1.3.44.M

6.1.3.44.5 Property sets

  • Pset_Condition
    • AssessmentDate
    • AssessmentCondition
    • AssessmentDescription
    • AssessmentType
    • AssessmentMethod
    • LastAssessmentReport
    • NextAssessmentDate
    • AssessmentFrequency
  • Pset_ConstructionAdministration
    • ProcurementMethod
    • SpecificationSectionNumber
    • SubmittalIdentifer
  • Pset_ConstructionOccurence
    • InstallationDate
    • ModelNumber
    • TagNumber
    • AssetIdentifier
  • Pset_DoorWindowGlazingType
    • GlassLayers
    • GlassThickness1
    • GlassThickness2
    • GlassThickness3
    • FillGas
    • GlassColour
    • IsTempered
    • IsLaminated
    • IsCoated
    • IsWired
    • VisibleLightReflectance
    • VisibleLightTransmittance
    • SolarAbsorption
    • SolarReflectance
    • SolarTransmittance
    • SolarHeatGainTransmittance
    • ShadingCoefficient
    • ThermalTransmittanceSummer
    • ThermalTransmittanceWinter
  • Pset_ElementKinematics
    • CyclicPath
    • CyclicRange
    • LinearPath
    • LinearRange
    • MaximumAngularVelocity
    • MaximumConstantSpeed
    • MinimumTime
  • Pset_EnvironmentalCondition
    • ReferenceAirRelativeHumidity
    • ReferenceEnvironmentTemperature
    • MaximumAtmosphericPressure
    • StorageTemperatureRange
    • MaximumWindSpeed
    • OperationalTemperatureRange
    • MaximumRainIntensity
    • SaltMistLevel
    • SeismicResistance
    • SmokeLevel
    • MaximumSolarRadiation
  • Pset_EnvironmentalImpactIndicators
    • Reference
    • FunctionalUnitReference
    • IndicatorsUnit
    • LifeCyclePhase
    • ExpectedServiceLife
    • TotalPrimaryEnergyConsumptionPerUnit
    • WaterConsumptionPerUnit
    • HazardousWastePerUnit
    • NonHazardousWastePerUnit
    • ClimateChangePerUnit
    • AtmosphericAcidificationPerUnit
    • RenewableEnergyConsumptionPerUnit
    • NonRenewableEnergyConsumptionPerUnit
    • ResourceDepletionPerUnit
    • InertWastePerUnit
    • RadioactiveWastePerUnit
    • StratosphericOzoneLayerDestructionPerUnit
    • PhotochemicalOzoneFormationPerUnit
    • EutrophicationPerUnit
  • Pset_EnvironmentalImpactValues
    • TotalPrimaryEnergyConsumption
    • WaterConsumption
    • HazardousWaste
    • NonHazardousWaste
    • ClimateChange
    • AtmosphericAcidification
    • RenewableEnergyConsumption
    • NonRenewableEnergyConsumption
    • ResourceDepletion
    • InertWaste
    • RadioactiveWaste
    • StratosphericOzoneLayerDestruction
    • PhotochemicalOzoneFormation
    • Eutrophication
    • LeadInTime
    • Duration
    • LeadOutTime
  • Pset_InstallationOccurrence
    • InstallationDate
    • AcceptanceDate
    • PutIntoOperationDate
  • Pset_MaintenanceStrategy
    • AssetCriticality
    • AssetFrailty
    • AssetPriority
    • MonitoringType
    • AccidentResponse
  • Pset_MaintenanceTriggerCondition
    • ConditionTargetPerformance
    • ConditionMaintenanceLevel
    • ConditionReplacementLevel
    • ConditionDisposalLevel
  • Pset_MaintenanceTriggerDuration
    • DurationTargetPerformance
    • DurationMaintenanceLevel
    • DurationReplacementLevel
    • DurationDisposalLevel
  • Pset_MaintenanceTriggerPerformance
    • TargetPerformance
    • PerformanceMaintenanceLevel
    • ReplacementLevel
    • DisposalLevel
  • Pset_ManufacturerOccurrence
    • AcquisitionDate
    • BarCode
    • SerialNumber
    • BatchReference
    • AssemblyPlace
    • ManufacturingDate
  • Pset_ManufacturerTypeInformation
    • GlobalTradeItemNumber
    • ArticleNumber
    • ModelReference
    • ModelLabel
    • Manufacturer
    • ProductionYear
    • AssemblyPlace
    • OperationalDocument
    • SafetyDocument
    • PerformanceCertificate
  • Pset_PermeableCoveringProperties
    • OperationType
    • PanelPosition
    • FrameDepth
    • FrameThickness
  • Pset_RepairOccurrence
    • RepairContent
    • RepairDate
    • MeanTimeToRepair
  • Pset_Risk
    • RiskName
    • RiskType
    • NatureOfRisk
    • RiskAssessmentMethodology
    • UnmitigatedRiskLikelihood
    • UnmitigatedRiskConsequence
    • UnmitigatedRiskSignificance
    • MitigationPlanned
    • MitigatedRiskLikelihood
    • MitigatedRiskConsequence
    • MitigatedRiskSignificance
    • MitigationProposed
    • AssociatedProduct
    • AssociatedActivity
    • AssociatedLocation
  • Pset_ServiceLife
    • ServiceLifeDuration
    • MeanTimeBetweenFailure
  • Pset_Tolerance
    • ToleranceDescription
    • ToleranceBasis
    • OverallTolerance
    • HorizontalTolerance
    • OrthogonalTolerance
    • VerticalTolerance
    • PlanarFlatness
    • HorizontalFlatness
    • ElevationalFlatness
    • SideFlatness
    • OverallOrthogonality
    • HorizontalOrthogonality
    • OrthogonalOrthogonality
    • VerticalOrthogonality
    • OverallStraightness
    • HorizontalStraightness
    • OrthogonalStraightness
    • VerticalStraightness
  • Pset_Uncertainty
    • UncertaintyBasis
    • UncertaintyDescription
    • HorizontalUncertainty
    • LinearUncertainty
    • OrthogonalUncertainty
    • VerticalUncertainty
  • Pset_Warranty
    • WarrantyIdentifier
    • WarrantyStartDate
    • IsExtendedWarranty
    • WarrantyPeriod
    • WarrantyContent
    • PointOfContact
    • Exclusions
  • Pset_WindowCommon
    • Reference
    • Status
    • AcousticRating
    • FireRating
    • SecurityRating
    • IsExternal
    • Infiltration
    • ThermalTransmittance
    • GlazingAreaFraction
    • HasSillExternal
    • HasSillInternal
    • HasDrive
    • SmokeStop
    • FireExit
    • WaterTightnessRating
    • MechanicalLoadRating
    • WindLoadRating
  • Pset_WindowLiningProperties
    • LiningDepth
    • LiningThickness
    • TransomThickness
    • MullionThickness
    • FirstTransomOffset
    • SecondTransomOffset
    • FirstMullionOffset
    • SecondMullionOffset
    • LiningOffset
    • LiningToPanelOffsetX
    • LiningToPanelOffsetY
  • Pset_WindowPanelProperties
    • OperationType
    • PanelPosition
    • FrameDepth
    • FrameThickness
  • Qto_BodyGeometryValidation
    • GrossSurfaceArea
    • NetSurfaceArea
    • GrossVolume
    • NetVolume
    • SurfaceGenusBeforeFeatures
    • SurfaceGenusAfterFeatures
  • Qto_WindowBaseQuantities
    • Width
    • Height
    • Perimeter
    • Area

6.1.3.44.6 Concept usage

Concept Usage Description
IfcRoot (2)
IfcObjectDefinition (9)
IfcObject (5)
IfcProduct (18)
IfcElement (44)
IfcBuiltElement (3)
Click to show 81 hidden inherited concepts
IfcWindow (10)
Material Set General

This concept can be applied to the following resources:

  • Lining - Indicates that the material constituent applies to the window lining.
  • Framing - Indicates that the material constituent applies to the windows panels(s); if not provided, the 'Lining' material information applies to panel(s) as well.
  • Glazing - Indicates that the material constituent applies to the glazing part.
Material Single General

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

Object Typing General

This concept can be applied to the following resources:

Product Local Placement General
  • 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.
  • 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.
  • If the relative placement is not used, the absolute placement is defined within the world coordinate system.
Profile 3D Geometry General

The window profile is represented by a three-dimensional closed curve lying in the xz plane. The profile is used to apply the parameters of a parametric door representation. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

  • RepresentationIdentifier: 'Profile'
  • RepresentationType: 'Curve3D' or 'GeometricCurveSet'. In case of 'GeometricCurveSet' 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 6.1.3.44.D, 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 6.1.3.44.D — Window profile

Figure 6.1.3.44.E illustrates the insertion of a parametrically generated 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 6.1.3.44.E — Window placement

Figure 6.1.3.44.F illustrates the final window (DoublePanelHorizontal) with first panel having PanelPosition = TOP, OperationType = BOTTOMHUNG and second panel having PanelPosition = BOTTOM and OperationType = TILTANDTURNLEFTHAND.

window 2
Figure 6.1.3.44.F — Window planes
Property Sets for Objects General

This concept can be applied to the following resources:

Quantity Sets General

This concept can be applied to the following resources:

Spatial Containment General

The IfcWindow, as any subtype of IfcBuiltElement, 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 6.1.3.44.G.

Containment
Figure 6.1.3.44.G — Window spatial containment
Window Attributes General

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 and its symbolic presentation of the IfcWindow is determined by its IfcWindowType.PartitioningType. The type determines the number and position of window panels. Depending on the type, the appropriate instances of IfcWindowLiningProperties and IfcWindowPanelProperties are attached in the list of HasPropertySets.

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 hinge side (whether a window opens to the left or to the right) is determined by the IfcWindowPanelProperties.OperationType.

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

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. Table 6.1.3.44.O illustrates window operation symbols from the exterior side (the convention as used predominately in Europe).

Diagram Description
fig 1
Figure 6.1.3.44.H
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
Figure 6.1.3.44.I
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
Figure 6.1.3.44.J
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
Figure 6.1.3.44.K
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.OperationType = SideHungRightHand.
Table 6.1.3.44.O — Window operations
Material Constituent Set General

No description available.

Table 6.1.3.44.N

6.1.3.44.7 Formal representation

ENTITY IfcWindow
SUBTYPE OF (IfcBuiltElement);
OverallHeight : OPTIONAL IfcPositiveLengthMeasure;
OverallWidth : OPTIONAL IfcPositiveLengthMeasure;
PredefinedType : OPTIONAL IfcWindowTypeEnum;
PartitioningType : OPTIONAL IfcWindowTypePartitioningEnum;
UserDefinedPartitioningType : OPTIONAL IfcLabel;
WHERE
CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR
(PredefinedType <> IfcWindowTypeEnum.USERDEFINED) OR
((PredefinedType = IfcWindowTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
CorrectTypeAssigned : (SIZEOF(IsTypedBy) = 0) OR
('IFC4X3_DEV_54a9de1b.IFCWINDOWTYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));
END_ENTITY;

6.1.3.44.8 References

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6.1.3.44.9 Changelog

6.1.3.44.9.1 IFC4

  • attribute, PartitioningType
  • attribute, PredefinedType
  • attribute, UserDefinedPartitioningType
  • where rule, CorrectStyleAssigned

6.1.3.44.9.2 IFC4.3_DEV_54a9de1b

  • where rule, CorrectPredefinedType
  • where rule, CorrectTypeAssigned
  • where rule, CorrectStyleAssigned
  • supertype, Changed from "IfcBuildingElement" to "IfcBuiltElement"