IfcBuildingStorey

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 311 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 311 — Building storey composition

Figure 312 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"

Figure 312 — Building storey elevations

HISTORY New entity in IFC1.0

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
10	Elevation	IfcLengthMeasure	?	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

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcRoot
1	GlobalId	IfcGloballyUniqueId		Assignment of a globally unique identifier within the entire software world.	X
2	OwnerHistory	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.	X
3	Name	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.	X
4	Description	IfcText	?	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). IFC4 CHANGE The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.	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). IFC4 CHANGE The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.	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. IFC4 CHANGE The inverse attribute datatype has been added.	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). IFC4 CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.	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). IFC4 CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.	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	?	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. IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange.	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. IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange.	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. 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
	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. IFC4 CHANGE The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.	X
IfcProduct
6	ObjectPlacement	IfcObjectPlacement	?	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	?	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
	PositionedRelativeTo	IfcRelPositions @RelatedProducts	S[0:?]		X
	ReferencedInStructures	IfcRelReferencedInSpatialStructure @RelatedElements	S[0:?]		X
IfcSpatialElement
8	LongName	IfcLabel	?	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. IFC4 CHANGE The inverse attribute has been promoted to the new supertype IfcSpatialElement with upward compatibility for file based exchange.	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. IFC2x3 CHANGE The inverse attribute has been added with upward compatibility for file based exchange. Ø\X	X
	IsInterferedByElements	IfcRelInterferesElements @RelatedElement	S[0:?]	Reference to the interference relationship to indicate the spatial element that is interfered. The relationship, if provided, indicates that this spatial element has an interference with one or many other spatial elements. NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements orientated interference is defined by IfcRelInterferesElements.ImpliedOrder or IfcRelInterferesElements.InterferenceType. IFC4x3 CHANGE New inverse relationship.	X
	InterferesElements	IfcRelInterferesElements @RelatingElement	S[0:?]	Reference to the interference relationship to indicate the spatial element that interferes. The relationship, if provided, indicates that this spatial element has an interference with one or many other spatial elements. NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements. Orientated interference is defined by IfcRelInterferesElements.ImpliedOrder or IfcRelInterferesElements.InterferenceType. IFC4x3 CHANGE New inverse relationship.	X
IfcSpatialStructureElement
9	CompositionType	IfcElementCompositionEnum	?	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
10	Elevation	IfcLengthMeasure	?	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

IfcBuildingStorey

Concept usage

Storey Identity

The Storey Attributes concept applies to this entity.

Spatial Composition

The Spatial Composition concept template applies to this entity as shown in Table 67.

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

Table 67 — 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 68.

RelatedObjects	Description
	Reference to the spaces that are assigned to this storey.

Table 68 — 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 template applies to this entity as shown in Table 69.

PsetName

Properties

Pset_BuildingStoreyCommon

Template	PropertyName	Value
Single Value	Reference	IfcIdentifier
Single Value	EntranceLevel	IfcBoolean
Single Value	AboveGround	IfcLogical
Single Value	SprinklerProtection	IfcBoolean
Single Value	SprinklerProtectionAutomatic	IfcBoolean
Single Value	LoadBearingCapacity	IfcPlanarForceMeasure
Single Value	GrossPlannedArea	IfcAreaMeasure
Single Value	NetPlannedArea	IfcAreaMeasure

Table 69 — IfcBuildingStorey Property Sets for Objects

Quantity Sets

The Quantity Sets concept template applies to this entity as shown in Table 70.

QsetName	Quantities
Qto_BuildingStoreyBaseQuantities

Table 70 — 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.

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 template applies to this entity as shown in Table 71.

Table 71 — 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 72.

Table 72 — 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="3662100e-85bd-49f7-a022-ccd975b62bf7" name="Storey Identity">

   <Template ref="488c9bb2-3102-4b89-bd20-42aa7060ae08" />

  </Concept>

  <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

#	Concept	Template	Model View
IfcRoot
	Identity	Software Identity	General Usage
	Revision Control	Revision Control	General Usage
IfcObjectDefinition
	Classification Association	Classification Association	General Usage
	Assignment to Product	Assignment to Product	General Usage
IfcObject
	Object User Identity	Object User Identity	General Usage
	Object Predefined Type	Object Predefined Type	General Usage
	Object Typing	Object Typing	General Usage
	Property Sets with Override	Property Sets with Override	General Usage
IfcProduct
	Product Placement	Product Placement	General Usage
	Product Geometric Representation	Product Geometric Representation	General Usage
	Relative Position	Product Relative Positioning	General Usage
	Product Span Positioning	Product Span Positioning	General Usage
	Product Geometry Colour	Product Geometry Colour	General Usage
	Product Geometry Layer	Product Geometry Layer	General Usage
	Product Relative Placement	Product Relative Placement	General Usage
IfcSpatialElement
	Group Spatial Connectivity	Group Spatial Connectivity	General Usage
	Spatial Interference	Spatial Interference	General Usage
	Spatial Interference with Zones	Spatial Interference With Zones	General Usage
IfcBuildingStorey
	Storey Identity	Storey Attributes	General Usage
	Spatial Composition	Spatial Composition	General Usage
	Spatial Decomposition	Spatial Decomposition	General Usage
	Spatial Container	Spatial Container	General Usage
	Property Sets for Objects	Property Sets for Objects	General Usage
	Quantity Sets	Quantity Sets	General Usage
	Placement	Product Local Placement	General Usage
	FootPrint GeomSet Geometry	FootPrint GeomSet Geometry	General Usage
	Body Geometry	Body Geometry	General Usage

Item	Change	Description
IFC2x3 to IFC4 4.0.0.0
IfcBuildingStorey
OwnerHistory	MODIFIED	Instantiation changed to OPTIONAL.
CompositionType	MODIFIED	Instantiation changed to OPTIONAL.
IFC4x2 Candidate 4.2.0.0
IfcBuildingStorey
PositionedRelativeTo	ADDED
IFC4x2 to IFC4x3_RC1
IfcBuildingStorey
ReferencedInStructures	ADDED
IFC4x3_RC4 Update
IfcBuildingStorey
IsInterferedByElements	ADDED
InterferesElements	ADDED

	Geschoss
	Building Storey
	Niveau

IfcBuildingStorey

Semantic definitions at the entity

Inherited definitions from supertypes

Definitions applying to General Usage

IfcBuildingStorey

Formal representations