IFC 4.3.x development

7.1.3.4 IfcPermeableCoveringProperties

Change log

IFC4

modificationssupertypeChanged from IfcPropertySetDefinition to IfcPreDefinedPropertySet

7.1.3.4.1 Semantic definitions at the entity

This entity is a description of a panel within a door or window (as fillers for opening) which allows for air flow. It is given by its properties (IfcPermeableCoveringProperties). A permeable covering is a casement, such as a component, fixed or opening, consisting essentially of a frame and the infilling. The infilling is normally a grill, a louver or a screen. The way of operation is defined in the operation type.

The IfcPermeableCoveringProperties are included in the list of properties (HasPropertySets) of the IfcWindowStyle or the IfcDoorStyle. More information about the permeable covering can be included in the same list of the window or door style using the IfcPropertySet for dynamic extensions. This particularly applies for additional properties for the various operation types

The IfcPermeableCoveringProperties does not hold a geometric representation. However it defines parameters which can be used to create the shape of the IfcWindowStyle (which is inserted by the IfcWindow into the spatial context of the project), or of the IfcDoorStyle (which is inserted by the IfcDoor).

The parameters at the IfcPermeableCoveringProperties define a standard permeable covering. The outer boundary of the panel is determined by the occurrence parameter assigned to the IfcWindow or IfcDoor. It has to take the lining parameter into account as well. The position of the permeable covering within the overall window or door is determined by the PanelPosition attribute.

Figure 1 illustrates the panel applied to the position within the lining, as defined by the panel position attribute. The following parameters apply to that panel: FrameDepth, FrameThickness.

"covering"

HISTORY  New entity in IFC2.0, it had been renamed from IfcPermeableCovering in IFC2x.

IFC4 CHANGE  Supertype changed to new IfcPreDefinedPropertySet.

7.1.3.4.1 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.
IfcPropertyDefinition
HasContext SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions
HasAssociations SET [0:?] OF IfcRelAssociates FOR RelatedObjects Reference to the relationship IfcRelAssociates and thus to those externally defined concepts, like classifications, documents, or library information, which are associated to the property definition.
IfcPropertySetDefinition
DefinesType SET [0:?] OF IfcTypeObject FOR HasPropertySets The type object to which the property set is assigned. The property set acts as a shared property set to all occurrences of the type object.

> NOTE  The relationship between the IfcPropertySetDefinition and the IfcTypeObject is a direct relationship, not utilizing IfcRelDefinesByProperties, for maintaining compatibility with earlier releases of this standard.

> IFC4 CHANGE  The cardinality has been changed from 0:1 to 0:? with upward compatibility for file based exchange.
IsDefinedBy SET [0:?] OF IfcRelDefinesByTemplate FOR RelatedPropertySets Relation to the property set template, via the objectified relationship IfcRelDefinesByTemplate, that, if given, provides the definition template for the property set or quantity set and its properties.

> IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
DefinesOccurrenceSET [0:?] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinitionReference to the relation to one or many object occurrences that are characterized by the property set definition. A single property set can be assigned to multiple object occurrences using the objectified relationship IfcRefDefinesByProperties.

> IFC4 CHANGE Inverse attribute renamed from PropertyDefinitionOf with upward compatibility for file-based exchange.
IfcPreDefinedPropertySet
IfcPermeableCoveringProperties
5 OperationType IfcPermeableCoveringOperationEnum Types of permeable covering operations. Also used to assign standard symbolic presentations according to national building standards.
6 PanelPosition IfcWindowPanelPositionEnum Position of this permeable covering panel within the overall window or door type.
7 FrameDepth OPTIONAL IfcPositiveLengthMeasure Depth of panel frame (used to include the permeable covering), measured from front face to back face horizontally (i.e. perpendicular to the window or door (elevation) plane.
8 FrameThickness OPTIONAL IfcPositiveLengthMeasure Width of panel frame (used to include the permeable covering), measured from inside of panel (at permeable covering) to outside of panel (at lining), i.e. parallel to the window or door (elevation) plane.
9 ShapeAspectStyle OPTIONAL IfcShapeAspect Optional link to a shape aspect definition, which points to the part of the geometric representation of the window style, which is used to represent the permeable covering.

7.1.3.4.2 Entity inheritance

dot_inheritance IfcPermeableCoveringProperties IfcPermeableCoveringProperties IfcPreDefinedPropertySet IfcPreDefinedPropertySet IfcPermeableCoveringProperties->IfcPreDefinedPropertySet IfcPreDefinedPropertySet_children 5 more... IfcPreDefinedPropertySet_children->IfcPreDefinedPropertySet IfcPropertySetDefinition IfcPropertySetDefinition IfcPreDefinedPropertySet->IfcPropertySetDefinition IfcPropertySet IfcPropertySet IfcPropertySet->IfcPropertySetDefinition IfcPropertyDefinition IfcPropertyDefinition IfcPropertySetDefinition->IfcPropertyDefinition IfcQuantitySet IfcQuantitySet IfcQuantitySet->IfcPropertySetDefinition IfcPropertyTemplateDefinition IfcPropertyTemplateDefinition IfcPropertyTemplateDefinition->IfcPropertyDefinition IfcRoot IfcRoot IfcPropertyDefinition->IfcRoot IfcObjectDefinition IfcObjectDefinition IfcObjectDefinition->IfcRoot IfcRelationship IfcRelationship IfcRelationship->IfcRoot

7.1.3.4.3 Definitions applying to General Usage

7.1.3.4.3.1 Identity

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

7.1.3.4.3.2 Revision Control

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

7.1.3.4.4 Formal representations

ENTITY IfcPermeableCoveringProperties
 SUBTYPE OF (IfcPreDefinedPropertySet);
	OperationType : IfcPermeableCoveringOperationEnum;
	PanelPosition : IfcWindowPanelPositionEnum;
	FrameDepth : OPTIONAL IfcPositiveLengthMeasure;
	FrameThickness : OPTIONAL IfcPositiveLengthMeasure;
	ShapeAspectStyle : OPTIONAL IfcShapeAspect;
END_ENTITY;