5.4.3.26 IfcSpace

	Local
	Raum

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 follow:

• 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 IfcRelAggregates.

Figure 96 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 96 — 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 LongName.
• 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 97 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 97 — Space elevations

Plumbing System Design

 Instance diagram

The Identity concept applies to this entity.

Exchange
Import			R	R	R	R	R	R	-		R	R	R
Export			R	R	R	R	R	R	-		R	R	R

The Object Typing concept applies to this entity as shown in Table 22.

Type IfcSpaceType

Table 22 — IfcSpace Object Typing

Exchange
Import									-
Export				O	O	O	O	O	-		O	O	O

Classification

The Classification concept applies to this entity as shown in Table 23.

Source Name Tokens Description CSI OmniClass 13-00 00 00 Spaces By Function

Table 23 — IfcSpace Classification

Exchange
Import	-	-	-	R	R	R	R	R	-		R	R	R
Export				R	R	R	R	R	-		R	R	R

Properties for Occurrences

The Properties for Occurrences concept applies to this entity as shown in Table 24.

PredefinedType Name   Pset_SpaceOccupancyRequirements   Pset_SpaceCommon

Table 24 — IfcSpace Properties for Occurrences

Exchange
Import									-
Export				O	O	O	O	O	-		O	O	O

Quantity Sets

The Quantity Sets concept applies to this entity as shown in Table 25.

Exchange
Import
Export											O	O	O

Space Boundaries

The Space Boundaries concept applies to this entity.

The Placement concept applies to this entity as shown in Table 26.

Type IfcLocalPlacement

Table 26 — IfcSpace Placement

Exchange
Import
Export											R	R	R

Footprint Geometry

The Footprint Geometry concept applies to this entity as shown in Table 27.

RepresentationType Geometry GeometricCurveSet IfcGeometricCurveSet

Table 27 — IfcSpace Footprint Geometry

The 2D geometric representation of IfcSpace is defined using the 'Curve2D' or 'GeometricCurveSet' geometry. The following attribute values should be inserted

• IfcShapeRepresentation.RepresentationIdentifier = 'FootPrint'.
• IfcShapeRepresentation.RepresentationType = 'Curve2D' or 'GeometricCurveSet' .

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. For spaces with inner boundaries, a set of IfcBoundedCurve's is used, that should be grouped into an IfcGeometricCurveSet.

Figure 98 shows a two-dimensional bounded curve representing the foot print of IfcSpace.

Figure 98 — Space footprint

Exchange
Import
Export											R	R	R

The Body Geometry concept applies to this entity as shown in Table 28.

RepresentationType Geometry SweptSolid IfcExtrudedAreaSolid Clipping IfcBooleanClippingResult Brep IfcFacetedBrep

Table 28 — IfcSpace Body Geometry

The standard geometric representation of IfcSpace is defined using the swept area solid geometry. The following attribute values should be inserted

• IfcShapeRepresentation.RepresentationIdentifier = 'Body'.
• IfcShapeRepresentation.RepresentationType = 'SweptSolid'.

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.

Figure 99 shows an extrusion of an arbitrary profile definition with voids into the swept area solid of IfcSpace.

Figure 99 — Space body swept solid

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.RepresentationIdentifier = 'Body'.
• IfcShapeRepresentation.RepresentationType = 'Clipping'.

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.

Figure 100 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 100 — Space body clipping

The fallback advanced geometric representation of IfcSpace is defined using the Brep solid geometry. It may be represented as a single or multiple instances of IfcFacetedBrep or IfcFacetedBrepWithVoids. The Brep representation allows for the representation of complex element shape. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

• IfcShapeRepresentation.RepresentationIdentifier : 'Body'
• IfcShapeRepresentation.RepresentationType : 'Brep'

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.

Exchange
Import
Export											R	R	R

XSD Specification:

EXPRESS Specification:

Attribute Definitions:

Formal Propositions:

Inheritance Graph:

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