IfcSpatialStructureElement

IfcSpatialStructureElement

Definition from IAI: A spatial structure element (IfcSpatialStructureElement) is the generalization of all spatial elements that might be used to define a spatial structure. That spatial structure is often used to provide a project structure to organize a building project.

A spatial project structure might define as many levels of decomposition as necessary for the building project. Elements within the spatial project structure are:

site as IfcSite
building as IfcBuilding
storey as IfcBuildingStorey
space as IfcSpace

or aggregations or parts thereof. The composition type declares an element to be either an element itself, or an aggregation (complex) or a decomposition (part). The interpretation of these types is given at each subtype of IfcSpatialStructureElement.

The IfcRelAggregates is defined as an 1-to-many relationship and used to establish the relationship between exactly two levels within the spatial project structure. Finally the highest level of the spatial structure is assigned to IfcProject using the IfcRelAggregates.

Informal proposition:

The spatial project structure, established by the IfcRelAggregates, shall be acyclic.
A site should not be (directly or indirectly) associated to a building, storey or space.
A building should not be (directly or indirectly) associated to a storey or space.
A storey should not be (directly or indirectly) associated to a space.

HISTORY New entity in IFC Release 2x

Use case:

The figure shows the use of IfcRelAggregates to establish a spatial structure including site, building, building section and storey.

EXPRESS specification:

ENTITY IfcSpatialStructureElement

ABSTRACT SUPERTYPE OF

(ONEOF(IfcBuilding, IfcBuildingStorey, IfcSpace, IfcSite))

SUBTYPE OF (

IfcProduct);

LongName

OPTIONAL IfcLabel;

CompositionType

IfcElementCompositionEnum;

INVERSE

ServicedBySystems

SET OF IfcRelServicesBuildings FOR RelatedBuildings;

ContainsElements

SET OF IfcRelContainedInSpatialStructure FOR RelatingStructure;

WHERE

WR41

(HIINDEX(SELF\IfcObject.Decomposes) = 1) AND ('IFCKERNEL.IFCRELAGGREGATES' IN TYPEOF(SELF\IfcObject.Decomposes[1])) AND (('IFCKERNEL.IFCPROJECT' IN TYPEOF (SELF\IfcObject.Decomposes[1].RelatingObject)) OR ('IFCPRODUCTEXTENSION.IFCSPATIALSTRUCTUREELEMENT' IN TYPEOF (SELF\IfcObject.Decomposes[1].RelatingObject)) );

END_ENTITY;

Attribute definitions:

LongName	:	Long name for a spatial structure element, used for informal purposes. Maybe used in conjunction with the inherited Name attribute.
CompositionType	:	Denotes, whether the predefined spatial structure element represents itself, or an aggregate (complex) or a part (part). The interpretation is given separately for each subtype of spatial structure element.
ServicedBySystems	:	Set of relationships to Systems, that provides a certain service to the Building. The relationship is handled by the objectified relationship IfcRelServicesBuildings.
ContainsElements	:	Set of relationships, that holds those elements, which are associated with this element of the spatial project structure.

Formal Propositions:

WR41

All spatial structure elements shall be associated (using the IfcRelAggregates relationship) with another spatial structure element, or with IfcProject.

Inheritance graph

ENTITY IfcSpatialStructureElement;

ENTITY IfcRoot;

GlobalId

IfcGloballyUniqueId;

OwnerHistory

IfcOwnerHistory;

Name

OPTIONAL IfcLabel;

Description

OPTIONAL IfcText;

ENTITY IfcObject;

ObjectType

OPTIONAL IfcLabel;

INVERSE

IsDefinedBy

SET OF IfcRelDefines FOR RelatedObjects;

HasAssociations

SET OF IfcRelAssociates FOR RelatedObjects;

HasAssignments

SET OF IfcRelAssigns FOR RelatedObjects;

Decomposes

SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;

IsDecomposedBy

SET OF IfcRelDecomposes FOR RelatingObject;

ENTITY IfcProduct;

ObjectPlacement

OPTIONAL IfcObjectPlacement;

Representation

OPTIONAL IfcProductRepresentation;

INVERSE

ReferencedBy

SET OF IfcRelAssignsToProduct FOR RelatingProduct;

ENTITY IfcSpatialStructureElement;

LongName

OPTIONAL IfcLabel;

CompositionType

IfcElementCompositionEnum;

INVERSE

ServicedBySystems

SET OF IfcRelServicesBuildings FOR RelatedBuildings;

ContainsElements

SET OF IfcRelContainedInSpatialStructure FOR RelatingStructure;

END_ENTITY;