A stair flight is an assembly of
building components in a single "run" of stair steps (not
interrupted by a landing). The stair steps and any stringers are
included in the stair flight. A winder is also regarded a part of
a stair flight.
An IfcStairFlight is normally aggregated by an
IfcStair through the IfcRelAggregates relationship,
the stair flight is then included in the set of
IfcRelAggregates.RelatedObjects. An IfcStairFlight
normally connects the floor slab of zero to two different storeys
(or partial storeys, or landings) within a building. The
connection relationship between the IfcStairFlight and the
IfcSlab is expressed using the
HISTORY New entity in IFC2.0.
Currently, the 'Axis', 'FootPrint', 'Body', and 'Box'
representations are supported. The 'Box' representation includes
the representation type 'BoundingBox' and is explained at
- Axis: A two-dimensional open curve
IfcBoundedCurve defining the walking line for the stair
- FootPrint: A geometric curve set defining the footing
print, including the boundary of the stair flight.
- Body: A solid representation defining the 3D shape of
the stair flight
Common Use Definitions
The following concepts are inherited at supertypes:
- IfcRoot: Identity, Revision Control
- IfcElement: Product Placement, Box Geometry, Body SurfaceOrSolidModel Geometry, Body SurfaceModel Geometry, Body Tessellation Geometry, Body Brep Geometry, Body AdvancedBrep Geometry, Body CSG Geometry, Mapped Geometry
- IfcBuildingElement: Product Assignment, Surface 3D Geometry
The Object Typing concept applies to this entity as shown in Table 178.
Table 178 — IfcStairFlight Object Typing
Property Sets for Objects
The Property Sets for Objects concept applies to this entity as shown in Table 179.
Table 179 — IfcStairFlight Property Sets for Objects
The Quantity Sets concept applies to this entity as shown in Table 180.
Table 180 — IfcStairFlight Quantity Sets
The Material Single concept applies to this entity.
The material of the IfcStairFlight is defined by the
IfcMaterial and attached by the
IfcRelAssociatesMaterial.RelatingMaterial. It is
accessible by the inverse HasAssociations
The Spatial Containment concept applies to this entity as shown in Table 181.
|IfcBuildingStorey||Default spatial container, if the stair flight is not used (by default) as a part within a stair container.|
|IfcBuilding||Spatial container for the element if it cannot be assigned to a building storey.|
|IfcSite||Spatial container for the element in case that it is placed on site (outside of building)|
Table 181 — IfcStairFlight Spatial Containment
The IfcStairFlight, as any subtype of IfcBuildingElement,
may participate alternatively in one of the two different containment relationships:
- the Spatial Containment (defined here), or
- the Element Composition.
NOTE Model view definitions or implementer agreements may force an IfcStairFlight to be solely used as a part within an IfcStair container. In this case, no Spatial containment shall be used.
Axis 2D Geometry
The Axis 2D Geometry concept applies to this entity.
The walking line is represented by a two-dimensional open
curve as the axis. The curve is directed into the upward
direction (direction has to be interpreted as specified at the
subtypes of IfcCurve).
Figure 216 illustrates the axis representation which has the following constraints:
- In case of straight flights the curve shall be a single item of type IfcPolyline.
- In case of winding flights the curve shall be a single item of type IfcCompositeCurve.
- In case of a curved flight or a spiral flight the curve shall be a single item of type IfcTrimmedCurve.
Figure 216 — Stair flight axis
The FootPrint Geometry concept applies to this entity as shown in Table 182.
|FootPrint||GeometricCurveSet|| ||Any collection of points and curves representing the floor plan projection.|
|FootPrint||Annotation2D|| ||Any collection of points and curves, and additional hatching and text representing the floor plan projection.|
Table 182 — IfcStairFlight FootPrint Geometry
The flight foot print, including the flight boundary is
represented by a two-dimensional geometric curve set.
Figure 217 illustrates the footprint representation which has the following constraints:
- In case of straight flights the curve set shall consists of a single item of type IfcPolyline.
- In case of winding flights or curved flights the curve set shall consists of a single item of type IfcCompositeCurve.
- In case of a spiral flight the curve set shall consists of a single item of type IfcConic or IfcPolyline.
Figure 217 — Stair flight footprint
Body SweptSolid Geometry
The Body SweptSolid Geometry concept applies to this entity.
Figure 218 illustrates the 'Body' geometric representation using a 'SweptSolid' representation type.
Figure 218 — Stair flight body
XSD Specification: <xs:element name="IfcStairFlight" type="ifc:IfcStairFlight" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>
<xs:attribute name="NumberOfRiser" type="xs:long" use="optional"/>
<xs:attribute name="NumberOfTreads" type="xs:long" use="optional"/>
<xs:attribute name="RiserHeight" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
<xs:attribute name="TreadLength" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
<xs:attribute name="PredefinedType" type="ifc:IfcStairFlightTypeEnum" use="optional"/>
|CorrectPredefinedType|| : ||NOT(EXISTS(PredefinedType)) OR
(PredefinedType <> IfcStairFlightTypeEnum.USERDEFINED) OR
((PredefinedType = IfcStairFlightTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));|
|CorrectTypeAssigned|| : ||(SIZEOF(IsTypedBy) = 0) OR
('IFCSHAREDBLDGELEMENTS.IFCSTAIRFLIGHTTYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy.RelatingType));|
|NumberOfRiser|| : ||
Number of the risers included in the stair flight
IFC4 CHANGE The attribute has been deprecated it shall only be exposed with a NIL value. Use Pset_StairFlightCommon.NumberOfRisers instead.
|NumberOfTreads|| : ||
Number of treads included in the stair flight.
IFC4 CHANGE The attribute has been deprecated it shall only be exposed with a NIL value. Use Pset_StairFlightCommon.NumberOfTreads instead.
|RiserHeight|| : ||
Vertical distance from tread to tread. The riser height is supposed to be equal for all stairs in a stair flight.
IFC4 CHANGE The attribute has been deprecated it shall only be exposed with a NIL value. Use Pset_StairFlightCommon.RiserHeight instead.
|TreadLength|| : ||
Horizontal distance from the front to the back of the tread. The tread length is supposed to be equal for all steps of the stair flight.
IFC4 CHANGE The attribute has been deprecated it shall only be exposed with a NIL value. Use Pset_StairFlightCommon.TreadLength instead.
|PredefinedType|| : ||
Predefined generic type for a stair flight that is specified in an enumeration. There may be a property set given specificly for the predefined types.
NOTE The PredefinedType shall only be used, if no IfcStairFlightType is assigned, providing its own IfcStairFlightType.PredefinedType.
IFC4 CHANGE The attribute has been added at the end of the entity definition.
|CorrectPredefinedType|| : ||
Either the PredefinedType attribute is unset (e.g. because an IfcStairFlightType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.
|CorrectTypeAssigned|| : ||
Either there is no stair flight type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcStairFlightType.
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