Definition from IAI: A space (IfcSpace) represents an area or volume bounded actually or theoretically. Spaces are areas or volumes that provide for certain functions within a building.
A space is (if specified) associated to a building storey (or in case of exterior spaces to a site). A space may span over several connected spaces. Therefore a space group provides for a collection of spaces included in a storey. A space can also be decomposed in parts, where each part defines a partial space. This is defined by the composition type attribute of the supertype IfcSpatialStructureElement which is interpreted as follow:
- COMPLEX = space group
- ELEMENT = space
- PARTIAL = partial space
The quantities relating to the space 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 |
| AverageHeight | Floor Height (without flooring) to Ceiling height (without suspended ceiling) for this space (measured from top of slab of this space to the bottom of slab of space above); the average shall be taken if room shape is not prismatic. | IfcLengthQuantity |
| AverageGrossHeight | Floor Height to Floor Height for this space (measured from top of slab of this space to top of slab of space above); the average shall be taken if room shape is not prismatic. | IfcLengthQuantity |
| AverageClearHeight | Clear Height between floor level (including finish) and ceiling level (including finish and sub construction) of this space; the average shall be taken if room shape is not prismatic. | IfcLengthQuantity |
| Perimeter | Perimeter at the floor level of this Space. The exact definition and calculation rules depend on the method of measurement used. | IfcLengthQuantity |
| Area | Area at the floor level of this space. The exact definition and calculation rules depend on the method of measurement used. | IfcAreaQuantity |
| Volume | Volume of this space. 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. See issue and change log for changes made in IFC Release 2x.
Use case:
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The following figure describes the heights and elevations of the IfcSpace. |
Geometry Use Definitions:
The geometric representation of IfcSpace is given by the IfcProductDefinitionShape and IfcLocalPlacement allowing multiple geometric representations.
NOTE1 If the surrounding instances of IfcRelSpaceBoundary define a complete geometric representation of a particular representation view for that space, than this view shall be omitted from the multiple representations of IfcSpace.
NOTE2 In cases of inconsistency between the geometric representation of the IfcSpace and its surrounding IfcRelSpaceBoundary, the geometric representation of the space should take priority over the geometric representation of the surrounding space boundaries.
Local Placement
The local placement for IfcSpace 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 to the local placement of the IfcSpatialStructureElement of type "IfcBuildingStorey", if relative placement is used, or of type "IfcSpace" (e.g. to position a space relative to a space group, or a partial space to a space).
- If the relative placement is not used, the absolute placement is defined within the world coordinate system.
Two-dimensional Representation using Curve2D representation
The 2D geometric representation of IfcSpace is defined using the Curve2D geometry. The following attribute values should be inserted
- IfcShapeRepresentation.RepresentationType = 'Curve2D'.
- IfcShapeRepresentation.RepresentationIdentifier = 'FootPrint'.
The following constraints apply to the 2D representation:
- Profile: IfcBoundedCurve is required, using IfcPolyline for faceted space contours or IfcCompositeCurve for space contours with arc segments.
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Two-dimensional bounded curve representing the foot print of IfcSpace. |
Standard Geometric Representation using Swept Solid representation
The standard geometric representation of IfcSpace is defined using the swept area solid geometry. The following attribute values should be inserted
- IfcShapeRepresentation.RepresentationType = 'SweptSolid'.
- IfcShapeRepresentation.RepresentationIdentifier = 'Body'.
The following constraints apply to the standard representation:
- Solid: IfcExtrudedAreaSolid is required,
- Profile: IfcArbitraryClosedProfileDef is required, IfcArbitraryProfileDefWithVoids shall be supported.
- Extrusion: The extrusion direction shall be vertically, i.e., along the positive Z Axis of the co-ordinate system of the containing spatial structure element.
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Extrusion of an arbitrary profile definition with voids into the swept area solid of IfcSpace. |
Advanced Geometric Representation using Clipping representation
The advanced geometric representation of IfcSpace is defined using the swept area solid geometry that can be subjected to a Boolean expression. The following attribute values should be inserted.
- IfcShapeRepresentation.RepresentationType = 'Clipping'.
- IfcShapeRepresentation.RepresentationIdentifier = 'Body'.
The following additional constraints apply to the advanced representation:
- Solid: see standard geometric representation,
- Profile: see standard geometric representation,
- Extrusion: see standard geometric representation,
- Boolean result: The difference operation with the second operand being of type IfcHalfSpaceSolid (or one of its subtypes) shall be supported.
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Extrusion of an arbitrary profile definition into the swept area solid. The solid and an half space solid are operands of the Boolean result of IfcSpace. |