IfcWindow

BACnet MVD

#### IfcWindow

Natural language names

| Fenster
| Window
| Fenêtre

Change log

Item | SPF | XML | Change | Description
--- | --- | --- | --- | ---
IFC2x3 to IFC4
IfcWindow |  |  |  |
OwnerHistory |  |  | MODIFIED | Instantiation changed to OPTIONAL.
PredefinedType |  |  | ADDED |
PartitioningType |  |  | ADDED |
UserDefinedPartitioningType |  |  | ADDED |

##### Semantic definitions at the entity

Entity 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.

> 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:

- be inserted into an IfcOpeningElement using the IfcRelFillsElement relationship, then the IfcWindow has an inverse attribute FillsVoids provided,
- be part of an element assembly, often an IfcCurtainWall, using the IfcRelAggregates relationship, then the inverse attribute Decomposes is provided.
- or be a "free standing" window, then the IfcWindow has no inverse attributes FillsVoids or Decomposes provided.

> 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 241 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.

Figure 241 — Window placement

Figure 242 illustrates the final window (DoublePanelHorizontal) with first panel having PanelPosition = TOP, OperationType = BOTTOMHUNG and second panel having PanelPosition = BOTTOM and OperationType = TILTANDTURNLEFTHAND.

Figure 242 — Window planes

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 243 illustrates window operation types.

| 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.
| 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.
| 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.
| 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. .

Figure 243 — Window operations

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---

9

OverallHeight

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.

X

10

OverallWidth

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.

X

11

PredefinedType

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.

X

12

PartitioningType

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.

X

13 | UserDefinedPartitioningType | IfcLabel | ? | Designator for the user defined partitioning type, shall only be provided, if the value of PartitioningType is set to USERDEFINED. |  | X

Formal Propositions

Rule | Description
--- | ---

CorrectStyleAssigned

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 IfcWindowStyle.

> NOTEnbsp; The deprecated type IfcWindowStyle is still included for backward compatibility reasons.

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcRoot
1 | GlobalId | IfcGloballyUniqueId |  | Assignment of a globally unique identifier within the entire software world. | X | X

2

OwnerHistory

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.

X

X

3 | Name | 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. | X | X
4 | Description | IfcText | ? | 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).

> IFC4 CHANGE The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.

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).

> IFC4 CHANGE The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.

X

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.

> IFC4 CHANGE The inverse attribute datatype has been added.

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).

> IFC4 CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.

X

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).

> IFC4 CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.

X

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 | X
IfcObject

5

ObjectType

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.

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.

> IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange.

X

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.

> IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange.

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.

> 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.

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.

> IFC4 CHANGE The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.

X

IfcProduct
6 | ObjectPlacement | 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. | X | X
7 | Representation | IfcProductRepresentation | ? | 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 | 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 | ? | 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 | 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.

> IFC4 CHANGE New inverse relationship.

X

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.

> IFC4 CHANGE New inverse relationship.

X

| HasProjections | IfcRelProjectsElement @RelatingElement | S[0:?] | Projection relationship that adds a feature (using a Boolean union) to the IfcBuildingElement. | X | 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.

> IFC2x3 CHANGE The inverse attribute has been added with upward compatibility for file based exchange.

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 | 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
IfcBuildingElement
IfcWindow

9

OverallHeight

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.

X

10

OverallWidth

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.

X

11

PredefinedType

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.

X

12

PartitioningType

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.

X

13 | UserDefinedPartitioningType | IfcLabel | ? | Designator for the user defined partitioning type, shall only be provided, if the value of PartitioningType is set to USERDEFINED. |  | X

##### Definitions applying to Design Transfer View

Concept inheritance

# | Concept | Template | Model View
--- | --- | --- | ---
IfcRoot
| Revision Control | Revision Control | Design Transfer View
IfcElement
| Product Grid Placement | Product Grid Placement | Design Transfer View
| Body SurfaceModel Geometry | Body SurfaceModel Geometry | Design Transfer View
| Body CSG Geometry | Body CSG Geometry | Design Transfer View
| Body Clipping Geometry | Body Clipping Geometry | Design Transfer View
| Body Brep Geometry | Body Brep Geometry | Design Transfer View
| Body AdvancedBrep Geometry | Body AdvancedBrep Geometry | Design Transfer View
| Element Projecting | Element Projecting | Design Transfer View
| Element Interference | Element Interference | Design Transfer View

##### Definitions applying to BACnet View

Concept inheritance

# | Concept | Template | Model View
--- | --- | --- | ---
IfcRoot
| Revision Control | Revision Control | Design Transfer View
IfcElement
| Product Grid Placement | Product Grid Placement | Design Transfer View
| Body SurfaceModel Geometry | Body SurfaceModel Geometry | Design Transfer View
| Body CSG Geometry | Body CSG Geometry | Design Transfer View
| Body Clipping Geometry | Body Clipping Geometry | Design Transfer View
| Body Brep Geometry | Body Brep Geometry | Design Transfer View
| Body AdvancedBrep Geometry | Body AdvancedBrep Geometry | Design Transfer View
| Element Projecting | Element Projecting | Design Transfer View
| Element Interference | Element Interference | Design Transfer View

##### Examples

- Wall with opening and window

##### Formal representations

XML Specification
`<xs:element name="IfcWindow" type="ifc:IfcWindow" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>
<xs:complexType name="IfcWindow">
<xs:complexContent>
<xs:extension base="ifc:IfcBuildingElement">
<xs:attribute name="OverallHeight" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
<xs:attribute name="OverallWidth" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
<xs:attribute name="PredefinedType" type="ifc:IfcWindowTypeEnum" use="optional"/>
<xs:attribute name="PartitioningType" type="ifc:IfcWindowTypePartitioningEnum" use="optional"/>
<xs:attribute name="UserDefinedPartitioningType" type="ifc:IfcLabel" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcWindow
SUPERTYPE OF(IfcWindowStandardCase)
SUBTYPE OF (IfcBuildingElement);
OverallHeight : OPTIONAL IfcPositiveLengthMeasure;
OverallWidth : OPTIONAL IfcPositiveLengthMeasure;
PredefinedType : OPTIONAL IfcWindowTypeEnum;
PartitioningType : OPTIONAL IfcWindowTypePartitioningEnum;
UserDefinedPartitioningType : OPTIONAL IfcLabel;
WHERE
CorrectStyleAssigned : (SIZEOF(IsTypedBy) = 0)
OR ('IFCSHAREDBLDGELEMENTS.IfcWindowType' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));
END_ENTITY;

EXPRESS-G diagram

`

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