IfcBuildingStorey

Natural language names
deGeschoss
enBuilding Storey
frNiveau
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcBuildingStorey
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      CompositionTypeMODIFIEDInstantiation changed to OPTIONAL.
Semantic definitions at the entity
Entity definition

The building storey has an elevation and typically represents a (nearly) horizontal aggregation of spaces that are vertically bound.

A storey is (if specified) associated to a building. A storey may span over several connected storeys. Therefore storey complex provides for a collection of storeys included in a building. A storey can also be decomposed in (horizontical) parts, where each part defines a partial storey. This is defined by the composition type attribute of the supertype IfcSpatialStructureElements which is interpreted as follow:

EXAMPLE  In split level houses, a storey is split into two or more partial storeys, each with a different elevation. It can be handled by defining a storey, which includes two or more partial storeys with the individual elevations.

The IfcBuildingStorey is used to build the spatial structure of a building (that serves as the primary project breakdown and is required to be hierarchical). The spatial structure elements are linked together by using the objectified relationship IfcRelAggregates.

Figure 138 shows the IfcBuildingStorey as part of the s patial structure. It also serves as the spatial container for building and other elements.

NOTE  Detailed requirements on mandatory element containment and placement structure relationships are given in view definitions and implementer agreements.
IfcBuildingStorey as part of a spatial structure

Figure 138 — Building storey composition

Figure 139 describes the heights and elevations of the IfcBuildingStorey.

space heights

Figure 139 — Building storey elevations

HISTORY  New entity in IFC1.0
Attribute definitions
#AttributeTypeCardinalityDescription C
10ElevationIfcLengthMeasure[0:1]

Elevation of the base of this storey, relative to the 0,00 internal reference height of the building. The 0.00 level is given by the absolute above sea level height by the ElevationOfRefHeight attribute given at IfcBuilding.

NOTE  If the geometric data is provided (ObjectPlacement is specified), the Elevation value shall either not be included, or be equal to the local placement Z value.
X
Inherited definitions from supertypes
Entity inheritance IfcSpatialStructureElement IfcSpatialElement IfcProduct IfcObject IfcObjectDefinition IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionC
IfcRoot
1GlobalIdIfcGloballyUniqueId[1:1] Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory[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
3NameIfcLabel[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
4DescriptionIfcText[0:1] Optional description, provided for exchanging informative comments.X
IfcObjectDefinition
HasAssignmentsIfcRelAssigns
@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
NestsIfcRelNests
@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
IsNestedByIfcRelNests
@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
HasContextIfcRelDeclares
@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
IsDecomposedByIfcRelAggregates
@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
DecomposesIfcRelAggregates
@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
HasAssociationsIfcRelAssociates
@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
5ObjectTypeIfcLabel[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
IsDeclaredByIfcRelDefinesByObject
@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
DeclaresIfcRelDefinesByObject
@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
IsTypedByIfcRelDefinesByType
@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
IsDefinedByIfcRelDefinesByProperties
@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
6ObjectPlacementIfcObjectPlacement[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
7RepresentationIfcProductRepresentation[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
ReferencedByIfcRelAssignsToProduct
@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
8LongNameIfcLabel[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
ContainsElementsIfcRelContainedInSpatialStructure
@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
ServicedBySystemsIfcRelServicesBuildings
@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
ReferencesElementsIfcRelReferencedInSpatialStructure
@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
IfcSpatialStructureElement
9CompositionTypeIfcElementCompositionEnum[0:1] 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. If no CompositionType is asserted, the dafault value 'ELEMENT' applies. X
IfcBuildingStorey
10ElevationIfcLengthMeasure[0:1]

Elevation of the base of this storey, relative to the 0,00 internal reference height of the building. The 0.00 level is given by the absolute above sea level height by the ElevationOfRefHeight attribute given at IfcBuilding.

NOTE  If the geometric data is provided (ObjectPlacement is specified), the Elevation value shall either not be included, or be equal to the local placement Z value.
X
Definitions applying to Common Use Definitions

 Instance diagram


Concept usage

Spatial Composition

The Spatial Composition concept applies to this entity as shown in Table 32.

Spatial CompositeDescription
IfcBuildingAssignment to the building, where the building storey is a part of.
IfcBuildingStoreyAssignment to another building storey, e.g. if this building storey is a partial storey that refer to another storey.

Table 32 — IfcBuildingStorey Spatial Composition

NOTE  By using the inverse relationship IfcBuildingStorey.Decomposes it references (IfcBuilding || IfcBuildingStorey) through IfcRelAggregates.RelatingObjectIfcBuildingStorey, the referenced IfcBuildingStorey needs to have a different and higher CompositionType, i.e. COMPLEX (if the other IfcBuildingStorey has ELEMENT), or ELEMENT (if the other IfcBuildingStorey has PARTIAL).


Spatial Decomposition

The Spatial Decomposition concept applies to this entity as shown in Table 33.

Spatial PartsDescription
IfcSpaceReference to the spaces that are assigned to this storey.
IfcBuildingStoreySpatial decomposition into partial stories, if this storey is a main storey having subdivisions.

Table 33 — IfcBuildingStorey Spatial Decomposition

NOTE  By using the inverse relationship IfcBuildingStorey.IsDecomposedBy it references IfcBuildingStorey || IfcSpace through IfcRelAggregates.RelatedObjects. If it refers to another instance of IfcBuildingStorey, the referenced IfcBuildingStorey needs to have a different and lower CompositionType, i.e. ELEMENT (if the other IfcBuildingStorey has COMPLEX), or PARTIAL (if the other IfcBuildingStorey has ELEMENT).
NOTE  Multi storey spaces shall be spatially contained by only a single building storey, usually it is the building storey where the base of the space lies.


Spatial Container

The Spatial Container concept applies to this entity.

If there are building elements and/or other elements directly related to the IfcBuildingStorey (like most building elements, such as walls, columns, etc.), they are associated with the IfcBuildingStorey by using the objectified relationship IfcRelContainedInSpatialStructure. The IfcBuildingStorey references them by its inverse relationship:

  • IfcBuildingStorey.ContainsElements -- referencing any subtype of IfcProduct (with the exception of other spatial structure element) by IfcRelContainedInSpatialStructure.RelatedElements.

Elements can also be referenced in an IfcBuildingStorey, for example, if they span through several storeys. This is expressed by using the objectified relationship IfcRelReferencedInSpatialStructure. Systems, such as building service or electrical distribution systems, zonal systems, or structural analysis systems, relate to IfcBuildingStorey by using the objectified relationship IfcRelServicesBuildings.



Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 34.

PredefinedTypeNameProperties
 Pset_BuildingStoreyCommonSingle Value
NameValue
ReferenceIfcIdentifier
EntranceLevelIfcBoolean
AboveGroundIfcLogical
SprinklerProtectionIfcBoolean
SprinklerProtectionAutomaticIfcBoolean
LoadBearingCapacityIfcPlanarForceMeasure
GrossPlannedAreaIfcAreaMeasure
NetPlannedAreaIfcAreaMeasure
 Pset_PropertyAgreementSingle Value
NameValue
IdentifierIfcIdentifier
VersionIfcLabel
VersionDateIfcDate
PropertyNameIfcLabel
CommencementDateIfcDate
TerminationDateIfcDate
DurationIfcDuration
OptionsIfcText
ConditionCommencementIfcText
RestrictionsIfcText
ConditionTerminationIfcText
Enumerated Value
NameValueValue
AgreementTypeIfcLabelIfcLabel
 Pset_ThermalLoadAggregateSingle Value
NameValue
TotalCoolingLoadIfcPowerMeasure
TotalHeatingLoadIfcPowerMeasure
LightingDiversityIfcPositiveRatioMeasure
InfiltrationDiversitySummerIfcPositiveRatioMeasure
InfiltrationDiversityWinterIfcPositiveRatioMeasure
ApplianceDiversityIfcPositiveRatioMeasure
LoadSafetyFactorIfcPositiveRatioMeasure
 Pset_ThermalLoadDesignCriteriaSingle Value
NameValue
OccupancyDiversityIfcPositiveRatioMeasure
OutsideAirPerPersonIfcVolumetricFlowRateMeasure
ReceptacleLoadIntensityIfcReal
AppliancePercentLoadToRadiantIfcPositiveRatioMeasure
LightingLoadIntensityIfcReal
LightingPercentLoadToReturnAirIfcPositiveRatioMeasure

Table 34 — IfcBuildingStorey Property Sets for Objects



Quantity Sets

The Quantity Sets concept applies to this entity as shown in Table 35.

Name
Qto_BuildingStoreyBaseQuantities

Table 35 — IfcBuildingStorey Quantity Sets



Product Local Placement

The Product Local Placement concept applies to this entity.

The local placement for IfcBuildingStorey is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.

  • The PlacementRelTo relationship of IfcLocalPlacement shall point (if relative placement is used) to the IfcSpatialStructureElement of type IfcBuilding, or of type IfcBuildingStorey (e.g. to position a building storey relative to a building storey complex, or a partial building storey to a building storey).
  • If the relative placement is not used, the absolute placement is defined within the world coordinate system.


FootPrint GeomSet Geometry

The FootPrint GeomSet Geometry concept applies to this entity as shown in Table 36.

IdentifierTypeItemsDescription
FootPrintGeometricCurveSetIfcGeometricCurveSetSet of curves (outer and inner) representing the floor projection,

Table 36 — IfcBuildingStorey FootPrint GeomSet Geometry

The foot print representation of IfcBuildingStorey is given by either a single 2D curve (such as IfcPolyline or IfcCompositeCurve), or by a list of 2D curves (in case of inner boundaries), if the building storey has an independent geometric representation.

NOTE  The independent geometric representation of IfcBuildingStorey may not be allowed in certain model view definitions. In those cases only the contained elements and spaces have an independent geometric representation.


Body Geometry

The Body Geometry concept applies to this entity as shown in Table 37.

IdentifierType
  

Table 37 — IfcBuildingStorey Body Geometry

The body (or solid model) geometric representation (if the building storey has an independent geometric representation) of IfcBuildingStorey is defined using faceted B-Rep capabilities (with or without voids), based on the IfcFacetedBrep or on the IfcFacetedBrepWithVoids.

NOTE  Since the building storey shape is usually described by the exterior building elements, an independent shape representation shall only be given, if the building storey is exposed independently from its constituting elements and such independent geometric representation may be prohibited in model view definitions.


Concept inheritance

#ConceptModel View
IfcRoot
Software IdentityCommon Use Definitions
Revision ControlCommon Use Definitions
IfcObject
Object Occurrence Predefined TypeCommon Use Definitions
IfcSpatialElement
IfcSpatialStructureElement
IfcBuildingStorey
Spatial CompositionCommon Use Definitions
Spatial DecompositionCommon Use Definitions
Spatial ContainerCommon Use Definitions
Property Sets for ObjectsCommon Use Definitions
Quantity SetsCommon Use Definitions
Product Local PlacementCommon Use Definitions
FootPrint GeomSet GeometryCommon Use Definitions
Body GeometryCommon Use Definitions
Formal representations
XSD Specification
 <xs:element name="IfcBuildingStorey" type="ifc:IfcBuildingStorey" substitutionGroup="ifc:IfcSpatialStructureElement" nillable="true"/>
 <xs:complexType name="IfcBuildingStorey">
  <xs:complexContent>
   <xs:extension base="ifc:IfcSpatialStructureElement">
    <xs:attribute name="Elevation" type="ifc:IfcLengthMeasure" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcBuildingStorey
 SUBTYPE OF (IfcSpatialStructureElement);
  Elevation : OPTIONAL IfcLengthMeasure;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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