Definition from IAI: The storey (IfcBuildingStorey) 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
splitted 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 quantities relating to the building storey are defined by the
IfcElementQuantity and attached by the IfcRelDefinesByProperties.
The following quantities are foreseen, but will be subjected to the local
standard of measurement:
| Name |
Description |
Value
Type |
| TotalHeight |
Calculated
height of this storey, from the bottom surface of the floor, to the bottom
surface of the floor or roof above. |
IfcLengthQuantity
|
| GrossFloorArea |
Calculated
sum of all areas covered by the building storey (as horizontal projections).
The exact definition and calculation rules depend on the method of measurement
used. |
IfcAreaQuantity |
| NetFloorArea |
Calculated
sum of all usable areas covered by the building storey (normally excluding the
area of construction elements). The exact definition and calculation rules
depend on the method of measurement used. |
IfcAreaQuantity |
| GrossVolume |
Calculated
gross volume of all areas enclosed by the building storey. The exact definition
and calculation rules depend on the method of measurement used. |
IfcVolumeQuantity |
HISTORY New entity in IFC
Release 1.0
ISSUE See issue log for changes made in IFC Release 1.5. and
1.5.1. See issue and change log for changes made in IFC Release
2x.
Geometry Use Definitions
The geometric representation of IfcBuildingStorey is given by the
IfcProductDefinitionShape and IfcLocalPlacement, allowing multiple geometric
representation.
Local Placement
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.
Standard Geometric Representation
The standard geometric representation (if the building has an
independent geometric representation) of IfcBuildingStorey is defined using
faceted B-Rep capabilities (with or without voids). The
IfcShapeRepresentation.RepresentationType is therefore 'Brep'.
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.
