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
- 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
Figure 113 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.
Figure 113 — Building storey composition
HISTORY New entity in IFC1.0
Attribute Use Definition
Figure 114 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 114 — Building storey elevations
Common Use Definitions
The following concepts are inherited at supertypes:
The Spatial Composition concept applies to this entity as shown in Table 32.
|IfcBuilding||Assignment to the building, where the building storey is a part of.|
|IfcBuildingStorey||Assignment 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).
The Spatial Decomposition concept applies to this entity as shown in Table 33.
|IfcSpace||Reference to the spaces that are assigned to this storey. |
|IfcBuildingStorey||Spatial 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.
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
- IfcBuildingStorey.ContainsElements -- referencing any
subtype of IfcProduct (with the exception of other spatial
structure element) by
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
Property Sets for Objects
The Property Sets for Objects concept applies to this entity as shown in Table 34.
Table 34 — IfcBuildingStorey Property Sets for Objects
The Quantity Sets concept applies to this entity as shown in Table 35.
Table 35 — IfcBuildingStorey Quantity Sets
The Product 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.
|FootPrint||GeometricCurveSet||IfcGeometricCurveSet||Set 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
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.
The Body Geometry concept applies to this entity as shown in Table 37.
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
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.
XSD Specification: <xs:element name="IfcBuildingStorey" type="ifc:IfcBuildingStorey" substitutionGroup="ifc:IfcSpatialStructureElement" nillable="true"/>
<xs:attribute name="Elevation" type="ifc:IfcLengthMeasure" use="optional"/>
|Elevation|| : ||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.|
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