IFC 4.3.x development

5.4.3.47 IfcRelReferencedInSpatialStructure

Change log

5.4.3.47.1 Semantic definitions at the entity

The objectified relationship, IfcRelReferencedInSpatialStructure is used to assign elements in addition to those levels of the project spatial structure, in which they are referenced, but not primarily contained. It is also used to connect a system to the relevant spatial element that it serves.

NOTE  The primary containment relationship between an element and the spatial structure is handled by IfcRelContainedInSpatialStructure.

Any element can be referenced to zero, one or several levels of the spatial structure. Whereas the IfcRelContainedInSpatialStructure relationship is required to be hierarchical (an element can only be contained in exactly one spatial structure element), the IfcRelReferencedInSpatialStructure is not restricted to be hierarchical.

EXAMPLE  A wall might be normally contained within a storey, and since it does not span through several stories, it is not referenced in any additional storey. However a curtain wall might span through several stories, in this case it can be contained within the ground floor, but it would be referenced by all additional stories, it spans.

Predefined spatial structure elements to which elements can be assigned are

• site as IfcSite
• facility as IfcFacility or its subtypes IfcBridge, IfcBuilding, IfcMarineFacility, IfcRailway or IfcRoad
• part of facility as IfcFaciltityPart, or more specifically as IfcBuildingStorey or IfcSpace

Elements can also be references in a spatial zone that is provided as IfcSpatialZone.

Figure 1 shows the use of IfcRelContainedInSpatialStructure and IfcRelReferencedInSpatialStructure to assign an IfcCurtainWall to two different levels within the spatial structure. It is primarily contained within the ground floor, and additionally referenced within the first and second floor.

HISTORY  New entity in IFC2x3.

5.4.3.47.1 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.
IfcRelationship
IfcRelConnects
IfcRelReferencedInSpatialStructure
5	RelatedElements	IfcProduct
6	RelatingStructure	IfcSpatialElement

5.4.3.47.2 Entity inheritance

5.4.3.47.3 Definitions applying to General Usage

5.4.3.47.3.1 Identity

5.4.3.47.3.2 Revision Control

5.4.3.47.4 Formal representations

ENTITY IfcRelReferencedInSpatialStructure
 SUBTYPE OF (IfcRelConnects);
	RelatingStructure : IfcSpatialElement;
	RelatedElements : IfcProduct;
 WHERE
	AllowedRelatedElements : SIZEOF(QUERY(temp <* RelatedElements | ('IFC4X3_RC3.IFCSPATIALSTRUCTUREELEMENT' IN TYPEOF(temp)) AND (NOT ('IFC4X3_RC3.IFCSPACE' IN TYPEOF(temp)))
)) = 0;
END_ENTITY;