IfcSpatialElement

Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcSpatialElement			ADDED

Semantic definitions at the entity

Entity definition

A spatial element is the generalization of all spatial elements that might be used to define a spatial structure or to define spatial zones.

a hierarchical spatial structure element as IfcSpatialStructureElement
- a spatial structure is a hiearchical decomposition of the project. 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, building, storey, and space
a spatial zone as IfcSpatialZone
- a spatial zone is a non-hierarchical and potentially overlapping decomposition of the project under some functional consideration.
- a spatial zone might be used to represent a thermal zone, a lighting zone, a usable area zone.
- a spatial zone might be used to represent a horizontal spatial structure as used in civil works.
- a spatial zone might have its independent placement and shape representation.

HISTORY New entity in IFC4.

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
8	LongName	IfcLabel	[0:1]	Long name for a spatial structure element, used for informal purposes. It should be used, if available, in conjunction with the inherited Name attribute. NOTE In many scenarios the Name attribute refers to the short name or number of a spacial element, and the LongName refers to the full descriptive name.	X
	ContainsElements	IfcRelContainedInSpatialStructure @RelatingStructure	S[0:?]	Set of spatial containment relationships, that holds those elements, which are contained within this element of the project spatial structure. NOTE The spatial containment relationship, established by IfcRelContainedInSpatialStructure, is required to be an hierarchical relationship, where each element can only be assigned to 0 or 1 spatial structure element.	X
	ServicedBySystems	IfcRelServicesBuildings @RelatedBuildings	S[0:?]	Set of relationships to systems, that provides a certain service to the spatial element for which it is defined. The relationship is handled by the objectified relationship IfcRelServicesBuildings.	X
	ReferencesElements	IfcRelReferencedInSpatialStructure @RelatingStructure	S[0:?]	Set of spatial reference relationships, that holds those elements, which are referenced, but not contained, within this element of the project spatial structure. NOTE The spatial reference relationship, established by IfcRelReferencedInSpatialStructure, is not required to be an hierarchical relationship, i.e. each element can be assigned to 0, 1 or many spatial structure elements. EXAMPLE A curtain wall maybe contained in the ground floor, but maybe referenced in all floors, it reaches. Ø\X	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcRoot
1	GlobalId	IfcGloballyUniqueId	[1:1]	Assignment of a globally unique identifier within the entire software world.	X
2	OwnerHistory	IfcOwnerHistory	[0:1]	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.	X
3	Name	IfcLabel	[0:1]	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
4	Description	IfcText	[0:1]	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).	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).	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.	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).	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).	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
IfcObject
5	ObjectType	IfcLabel	[0:1]	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.	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.	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.	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.	X
IfcProduct
6	ObjectPlacement	IfcObjectPlacement	[0:1]	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
7	Representation	IfcProductRepresentation	[0:1]	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
	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
IfcSpatialElement
8	LongName	IfcLabel	[0:1]	Long name for a spatial structure element, used for informal purposes. It should be used, if available, in conjunction with the inherited Name attribute. NOTE In many scenarios the Name attribute refers to the short name or number of a spacial element, and the LongName refers to the full descriptive name.	X
	ContainsElements	IfcRelContainedInSpatialStructure @RelatingStructure	S[0:?]	Set of spatial containment relationships, that holds those elements, which are contained within this element of the project spatial structure. NOTE The spatial containment relationship, established by IfcRelContainedInSpatialStructure, is required to be an hierarchical relationship, where each element can only be assigned to 0 or 1 spatial structure element.	X
	ServicedBySystems	IfcRelServicesBuildings @RelatedBuildings	S[0:?]	Set of relationships to systems, that provides a certain service to the spatial element for which it is defined. The relationship is handled by the objectified relationship IfcRelServicesBuildings.	X
	ReferencesElements	IfcRelReferencedInSpatialStructure @RelatingStructure	S[0:?]	Set of spatial reference relationships, that holds those elements, which are referenced, but not contained, within this element of the project spatial structure. NOTE The spatial reference relationship, established by IfcRelReferencedInSpatialStructure, is not required to be an hierarchical relationship, i.e. each element can be assigned to 0, 1 or many spatial structure elements. EXAMPLE A curtain wall maybe contained in the ground floor, but maybe referenced in all floors, it reaches. Ø\X	X

Definitions applying to Common Use Definitions

Instance diagram

Concept usage

Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 72.

PredefinedType

Name

Properties

Pset_ThermalLoadAggregate

Single Value

Name	Value
TotalCoolingLoad	IfcPowerMeasure
TotalHeatingLoad	IfcPowerMeasure
LightingDiversity	IfcPositiveRatioMeasure
InfiltrationDiversitySummer	IfcPositiveRatioMeasure
InfiltrationDiversityWinter	IfcPositiveRatioMeasure
ApplianceDiversity	IfcPositiveRatioMeasure
LoadSafetyFactor	IfcPositiveRatioMeasure

Pset_ThermalLoadDesignCriteria

Single Value

Name	Value
OccupancyDiversity	IfcPositiveRatioMeasure
OutsideAirPerPerson	IfcVolumetricFlowRateMeasure
ReceptacleLoadIntensity	IfcReal
AppliancePercentLoadToRadiant	IfcPositiveRatioMeasure
LightingLoadIntensity	IfcReal
LightingPercentLoadToReturnAir	IfcPositiveRatioMeasure

Table 72 — IfcSpatialElement Property Sets for Objects

FootPrint GeomSet Geometry

The FootPrint GeomSet Geometry concept applies to this entity as shown in Table 73.

Identifier	Type	Items	Description
FootPrint	GeometricCurveSet	IfcGeometricCurveSet	Set of curves (outer and inner) representing the floor projection,

Table 73 — IfcSpatialElement FootPrint GeomSet Geometry

Concept inheritance

#	Concept	Model View
IfcRoot
	Software Identity	Common Use Definitions
	Revision Control	Common Use Definitions
IfcObject
	Object Occurrence Predefined Type	Common Use Definitions
IfcSpatialElement
	Property Sets for Objects	Common Use Definitions
	FootPrint GeomSet Geometry	Common Use Definitions

Formal representations

XSD Specification

 <xs:element name="IfcSpatialElement" type="ifc:IfcSpatialElement" abstract="true" substitutionGroup="ifc:IfcProduct" nillable="true"/>

 <xs:complexType name="IfcSpatialElement" abstract="true">

  <xs:complexContent>

   <xs:extension base="ifc:IfcProduct">

    <xs:sequence>

     <xs:element name="ContainsElements" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:sequence>

        <xs:element ref="ifc:IfcRelContainedInSpatialStructure" minOccurs="0" maxOccurs="unbounded"/>

       </xs:sequence>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcRelContainedInSpatialStructure"/>

       <xs:attribute ref="ifc:cType" fixed="set"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

    </xs:sequence>

    <xs:attribute name="LongName" type="ifc:IfcLabel" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcSpatialElement

 ABSTRACT SUPERTYPE OF(ONEOF(IfcExternalSpatialStructureElement, IfcSpatialStructureElement, IfcSpatialZone))

 SUBTYPE OF (IfcProduct);

  LongName : OPTIONAL IfcLabel;

 INVERSE

  ContainsElements : SET OF IfcRelContainedInSpatialStructure FOR RelatingStructure;

  ServicedBySystems : SET OF IfcRelServicesBuildings FOR RelatedBuildings;

  ReferencesElements : SET OF IfcRelReferencedInSpatialStructure FOR RelatingStructure;

END_ENTITY;

 EXPRESS-G diagram

Link to this page

	Räumliches Element
	Spatial Element
	Element spatial