IfcBuildingStorey

Natural language names
Geschoss
Building Storey
Niveau
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4 4.0.0.0
    IfcBuildingStorey
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      CompositionTypeMODIFIEDInstantiation changed to OPTIONAL.
IFC4.2 Candidate 4.2.0.0
    IfcBuildingStorey
      PositionedRelativeToADDED
IFC4.2 to IFC4.3 RC1
    IfcBuildingStorey
      ReferencedInStructuresADDED
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:

* **COMPLEX**: building storey complex
* **ELEMENT**: building storey
* **PARTIAL**: partial building storey

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 149 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 149 — Building storey composition

Figure 150 describes the heights and elevations of the IfcBuildingStorey.

* elevation of storey provided by: IfcBuildingStorey.Elevation as a local height value relative to IfcBuilding.ElevationOfRefHeight, it is usually the top of construction slab
* net height of storey, also referred to as total height or system height (top of construction slab to top of construction slab above): provided by BaseQuantity with Name="GrossHeight"
* net height of storey (top of construction slab to bottom of construction slab above): provided by BaseQuantity with Name="NetHeight"

"space heights"

Figure 150 — Building storey elevations

HISTORY  New entity in IFC1.0

Attribute definitions
#AttributeTypeCardinalityDescription G
10ElevationIfcLengthMeasure? 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.\X\0D \X\0D
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
#AttributeTypeCardinalityDescriptionG
IfcRoot
1GlobalIdIfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory? 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.
X
3NameIfcLabel? 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? 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).
IFC4 CHANGE  The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
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).
IFC4 CHANGE  The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
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.
IFC4 CHANGE  The inverse attribute datatype has been added.
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).
IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
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).
IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
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? 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.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
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.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
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.
IFC4 CHANGE  New inverse relationship, the link to IfcRelDefinesByType had previously be included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
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.
IFC4 CHANGE  The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.
X
IfcProduct
6ObjectPlacementIfcObjectPlacement? 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? 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
PositionedRelativeToIfcRelPositions
@RelatedProducts
S[0:1]X
ReferencedInStructuresIfcRelReferencedInSpatialStructure
@RelatedElements
S[0:?]X
IfcSpatialElement
8LongNameIfcLabel? 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.
IFC4 CHANGE  The inverse attribute has been promoted to the new supertype IfcSpatialElement with upward compatibility for file based exchange.
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.
IFC2x3 CHANGE  The inverse attribute has been added with upward compatibility for file based exchange.
Ø\X
X
IfcSpatialStructureElement
9CompositionTypeIfcElementCompositionEnum? 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\0D \X\0D
IFC4 CHANGE  Attribute made optional.
X
IfcBuildingStorey
10ElevationIfcLengthMeasure? 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.\X\0D \X\0D
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 General Usage

 Instance diagram


Concept usage

Spatial Composition

The Spatial Composition concept template applies to this entity as shown in Table 39.

RelatingObjectDescription
Assignment to the building, where the building storey is a part of.

Table 39 — IfcBuildingStorey Spatial Composition

NOTE  By using the inverse relationship IfcBuildingStorey.Decomposes it references (IfcBuilding || IfcBuildingStorey) through IfcRelAggregates.RelatingObject_IfcBuildingStorey, 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 template applies to this entity as shown in Table 40.

RelatedObjectsDescription
Reference to the spaces that are assigned to this storey.

Table 40 — 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:

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 template applies to this entity as shown in Table 41.

PsetNameProperties
Pset_BuildingStoreyCommon
TemplatePropertyNameValue
Single ValueReferenceIfcIdentifier
Single ValueEntranceLevelIfcBoolean
Single ValueAboveGroundIfcLogical
Single ValueSprinklerProtectionIfcBoolean
Single ValueSprinklerProtectionAutomaticIfcBoolean
Single ValueLoadBearingCapacityIfcPlanarForceMeasure
Single ValueGrossPlannedAreaIfcAreaMeasure
Single ValueNetPlannedAreaIfcAreaMeasure

Table 41 — IfcBuildingStorey Property Sets for Objects



Quantity Sets

The Quantity Sets concept template applies to this entity as shown in Table 42.

QsetNameQuantities
Qto_BuildingStoreyBaseQuantities

Table 42 — IfcBuildingStorey Quantity Sets



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.



FootPrint GeomSet Geometry

The FootPrint GeomSet Geometry concept template applies to this entity as shown in Table 43.

Table 43 — 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 template applies to this entity as shown in Table 44.

Table 44 — 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.



mvdXML Specification
<?xml version="1.0" encoding="utf-8"?>
<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" uuid="cf8aa30c-8be2-4d8c-8cc8-290219cafe7b" name="IfcBuildingStorey" applicableRootEntity="IfcBuildingStorey">
 <Applicability>
  <Template ref="fbfb3429-6f5d-464b-915c-67ce25348ba0" />
  <TemplateRules operator="and">
  </TemplateRules>
 </Applicability>
 <Concepts>
  <Concept uuid="dee418f3-e5ea-4ade-914e-69e111bb4147" name="Spatial Composition">
   <Template ref="8c0fd2f7-71bb-4e6e-8fdb-0c02b352f14a" />
   <TemplateRules operator="and">
    <TemplateRule Description="Assignment to the building, where the building storey is a part of." />
    <TemplateRule Description="Assignment to another building storey, e.g. if this building storey is a partial storey that refer to another storey." />
   </TemplateRules>
  </Concept>
  <Concept uuid="d352d29a-b93d-4a25-a256-0846b34c133b" name="Spatial Decomposition">
   <Template ref="667f8443-ecce-4a8d-a63f-931fab0453e0" />
   <TemplateRules operator="and">
    <TemplateRule Description="Reference to the spaces that are assigned to this storey." />
    <TemplateRule Description="Spatial decomposition into partial stories, if this storey is a main storey having subdivisions." />
   </TemplateRules>
  </Concept>
  <Concept uuid="43072948-3a70-47ef-9885-23638400251e" name="Spatial Container">
   <Template ref="61dd08ed-fd01-4955-9337-8afd284a0e6f" />
  </Concept>
  <Concept uuid="a2ea2205-2632-4657-9377-101062e727fd" name="Property Sets for Objects">
   <Template ref="f74255a6-0c0e-4f31-84ad-24981db62461" />
   <TemplateRules operator="and">
    <TemplateRule Parameters="PsetName[Value]=&apos;Pset_BuildingStoreyCommon&apos;" />
   </TemplateRules>
  </Concept>
  <Concept uuid="2c028e8f-b8ad-4b5f-99a2-e9af8fbd481b" name="Quantity Sets">
   <Template ref="6652398e-6579-4460-8cb4-26295acfacc7" />
   <TemplateRules operator="and">
    <TemplateRule Parameters="QsetName[Value]=&apos;Qto_BuildingStoreyBaseQuantities&apos;" />
   </TemplateRules>
  </Concept>
  <Concept uuid="884de485-15e6-4c1b-81a5-52b49534cd53" name="Placement">
   <Template ref="cbe85b5f-7912-4a43-8bb7-1e63bf40b26d" />
  </Concept>
  <Concept uuid="3a7d8b5a-2c60-41a2-9b5f-2d47186b577b" name="FootPrint GeomSet Geometry">
   <Template ref="9456d6d6-a62a-48b4-baff-be2e38baac9c" />
  </Concept>
  <Concept uuid="3a23c0fb-c1e3-4d1f-bceb-9e0ffbb3e915" name="Body Geometry">
   <Template ref="c446bd16-2de3-4b97-b34f-4446ac0badc2" />
   <TemplateRules operator="and">
    <TemplateRule />
   </TemplateRules>
  </Concept>
 </Concepts>
</ConceptRoot>
Concept inheritance

#ConceptTemplateModel View
IfcRoot
IdentitySoftware IdentityGeneral Usage
Revision ControlRevision ControlGeneral Usage
IfcObjectDefinition
Classification AssociationClassification AssociationGeneral Usage
IfcObject
Object User IdentityObject User IdentityGeneral Usage
Object Predefined TypeObject Predefined TypeGeneral Usage
Object TypingObject TypingGeneral Usage
Property Sets with OverrideProperty Sets with OverrideGeneral Usage
IfcProduct
Product PlacementProduct PlacementGeneral Usage
Product Geometric RepresentationProduct Geometric RepresentationGeneral Usage
IfcBuildingStorey
Spatial CompositionSpatial CompositionGeneral Usage
Spatial DecompositionSpatial DecompositionGeneral Usage
Spatial ContainerSpatial ContainerGeneral Usage
Property Sets for ObjectsProperty Sets for ObjectsGeneral Usage
Quantity SetsQuantity SetsGeneral Usage
PlacementProduct Local PlacementGeneral Usage
FootPrint GeomSet GeometryFootPrint GeomSet GeometryGeneral Usage
Body GeometryBody GeometryGeneral Usage
Formal representations
XML 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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