A space 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 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
CompositionType attribute of the supertype IfcSpatialStructureElement which is interpreted as
- COMPLEX = space group
- ELEMENT = space
- PARTIAL = partial space
NOTE View definitions and implementation agreements may restrict spaces with CompositionType=ELEMENT to be non-overlapping.
The IfcSpace 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
Figure 148 shows the IfcSpace as part of the spatial structure. It also serves as the spatial container for space related elements.
NOTE Detailed requirements on mandatory element containment and placement structure relationships are given in view definitions and implementer agreements.
Figure 148 — Space composition
The following guidelines should apply for using the Name, Description, LongName and ObjectType attributes.
- Name holds the unique name (or space number) from the plan.
- Description holds any additional information field the
user may have specified, there are no further recommendations.
- LongName holds the full name of the space, it is often
used in addition to the Name, if a number is assigned to the
room, then the descriptive name is exchanged as
- ObjectType holds the space type, i.e. usually the
functional category of the space .
NOTE In cases of inconsistency between the
geometric representation of the IfcSpace and the combined
geometric representations of the surrounding
IfcRelSpaceBoundary, the geometric representation of the
space should take priority over the geometric representation of the
surrounding space boundaries.
HISTORY New entity in IFC1.0
Attribute Use Definition
Figure 149 describes the heights and elevations of the IfcSpace.
- elevation of the space (top of construction slab) equals elevation of storey: provided by IfcBuildingStorey.Elevation relative to IfcBuilding.ElevationOfRefHeight
- elevation of the space flooring (top of flooring on top of slab): provided by IfcSpace.ElevationWithFlooring relative to IfcBuilding.ElevationOfRefHeight
- height of space (top of slab below to bottom of slab above): provided by BaseQuantity with Name="Height"
- floor height of space (top of slab below to top of flooring): provided by BaseQuantity with Name="FinishFloorHeight"
- net height of space (top of flooring to bottom of suspended ceiling): provided by BaseQuantity with Name="FinishCeilingHeight"
Figure 149 — Space elevations
Common Use Definitions
The following concepts are inherited at supertypes:
The Spatial Decomposition concept applies to this entity.
By using the inverse relationship IfcSpace.Decomposes it references IfcSite ||
IfcBuildingStorey || IfcSpace by
IfcRelAggregates.RelatingObject. If it refers to another
instance of IfcSpace, the referenced IfcSpace
needs to have a different and higher CompositionType, i.e.
COMPLEX (if the other IfcSpace has ELEMENT), or ELEMENT (if
the other IfcSpace has PARTIAL).
The Spatial Composition concept applies to this entity.
By using the inverse relationship IfcSpace.IsDecomposedBy it references IfcSpace by IfcRelAggregates.RelatedObjects. If it refers to another
instance of IfcSpace, the referenced IfcSpace needs
to have a different and lower CompositionType, i.e. ELEMENT
(if the other IfcSpace has COMPLEX), or PARTIAL (if the
other IfcSpace has ELEMENT).
The Spatial Container concept applies to this entity.
If there are building elements and/or other elements directly
related to the IfcSpace (like most furniture and
distribution elements), they are associated with the
IfcSpace by using the objectified relationship
IfcRelContainedInSpatialStructure. The IfcSpace
references them by its inverse relationship:
- IfcSpace.ContainsElements -- referencing any subtype of
IfcProduct (with the exception of other spatial structure
Property Sets for Objects
The Property Sets for Objects concept applies to this entity as shown in Table 69.
Table 69 — IfcSpace Property Sets for Objects
The Quantity Sets concept applies to this entity as shown in Table 70.
Table 70 — IfcSpace Quantity Sets
The Space Boundaries concept applies to this entity.
The Product Placement concept applies to this entity.
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
- 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 71.
|FootPrint||Curve2D||IfcBoundedCurve||A single curve defining the outer boundary|
|FootPrint||GeometricCurveSet||IfcGeometricCurveSet||Set of curves (outer and inner) representing the floor projection,|
Table 71 — IfcSpace FootPrint GeomSet Geometry
The following constraints apply to the 2D representation:
EXAMPLE Figure 150 shows a two-dimensional bounded curve representing the
foot print of IfcSpace.
Figure 150 — Space footprint
Body SweptSolid Geometry
The Body SweptSolid Geometry concept applies to this entity.
The following constraints apply to the standard
Figure 151 shows an extrusion of an arbitrary profile definition with voids into the swept area solid of IfcSpace.
Figure 151 — Space body swept solid
Body Clipping Geometry
The Body Clipping Geometry concept applies to this entity.
The following additional constraints apply to the advanced
- 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.
Figure 152 shows an 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.
Figure 152 — Space body clipping
XSD Specification: <xs:element name="IfcSpace" type="ifc:IfcSpace" substitutionGroup="ifc:IfcSpatialStructureElement" nillable="true"/>
<xs:attribute name="PredefinedType" type="ifc:IfcSpaceTypeEnum" use="optional"/>
<xs:attribute name="ElevationWithFlooring" type="ifc:IfcLengthMeasure" use="optional"/>
|CorrectPredefinedType|| : ||NOT(EXISTS(PredefinedType)) OR
(PredefinedType <> IfcSpaceTypeEnum.USERDEFINED) OR
((PredefinedType = IfcSpaceTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));|
|CorrectTypeAssigned|| : ||(SIZEOF(IsTypedBy) = 0) OR
('IFCPRODUCTEXTENSION.IFCSPACETYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy.RelatingType));|
|PredefinedType|| : ||
Predefined generic types for a space that are specified in an enumeration. There might be property sets defined specifically for each predefined type.
NOTE Previous use had been to indicates whether the IfcSpace is an interior space by value INTERNAL, or an exterior space by value EXTERNAL. This use is now deprecated, the property 'IsExternal' at 'Pset_SpaceCommon' should be used instead.
IFC4 CHANGE The attribute has been renamed from ExteriorOrInteriorSpace with upward compatibility for file based exchange.
|ElevationWithFlooring|| : ||Level of flooring of this space; the average shall be taken, if the space ground surface is sloping or if there are level differences within this space. |
|HasCoverings|| : ||
Reference to IfcCovering by virtue of the objectified relationship IfcRelCoversSpaces. It defines the concept of a space having coverings assigned. Those coverings may represent different flooring, or tiling areas.
NOTE Coverings are often managed by the space, and not by the building element, which they cover.
IFC2x Edition3 CHANGE New inverse relationship. Upward compatibility for file based exchange is guaranteed.
|BoundedBy|| : ||
Reference to a set of IfcRelSpaceBoundary's that defines the physical or virtual delimitation of that space against physical or virtual boundaries.
|CorrectPredefinedType|| : ||
Either the PredefinedType attribute is unset (e.g. because an IfcSpaceType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.
|CorrectTypeAssigned|| : ||
Either there is no space type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcSpaceType.
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