#### 5.2.3.8 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 22 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 22 — 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 23 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 23 — Space elevations

## Mechanical System Design

Instance diagram

Classification

The Classification concept applies to this entity.

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

Identity

The Identity concept applies to this entity.

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

XSD Specification:

<xs:element name="IfcSpace" type="ifc:IfcSpace" substitutionGroup="ifc:IfcSpatialStructureElement" nillable="true"/>
<xs:complexType name="IfcSpace">
<xs:complexContent>
<xs:extension base="ifc:IfcSpatialStructureElement"/>
</xs:complexContent>
</xs:complexType>

EXPRESS Specification:

ENTITY IfcSpace

| SUBTYPE OF (IfcSpatialStructureElement);

PredefinedType | : | OPTIONAL IfcStrippedOptional;
ElevationWithFlooring | : | OPTIONAL IfcStrippedOptional;

| INVERSE

| WHERE

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[1].RelatingType));

END_ENTITY;

Attribute Definitions:

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.

Formal Propositions:

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.

Inheritance Graph:

ENTITY IfcSpace

| ENTITY IfcRoot

GlobalId | : | IfcGloballyUniqueId;
OwnerHistory | : | OPTIONAL IfcOwnerHistory;
Name | : | OPTIONAL IfcLabel;
Description | : | OPTIONAL IfcText;

| ENTITY IfcObjectDefinition

| INVERSE

HasAssignments | : | SET OF IfcRelAssigns FOR RelatedObjects;
HasContext | : | SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions;
IsDecomposedBy | : | SET OF IfcRelAggregates FOR RelatingObject;
Decomposes | : | SET [0:1] OF IfcRelAggregates FOR RelatedObjects;
HasAssociations | : | SET OF IfcRelAssociates FOR RelatedObjects;

| ENTITY IfcObject

ObjectType | : | OPTIONAL IfcStrippedOptional;

| INVERSE

IsTypedBy | : | SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects;

| ENTITY IfcProduct

ObjectPlacement | : | OPTIONAL IfcStrippedOptional;
Representation | : | OPTIONAL IfcStrippedOptional;

| INVERSE

| ENTITY IfcSpatialElement

LongName | : | OPTIONAL IfcStrippedOptional;

| INVERSE

| ENTITY IfcSpatialStructureElement

CompositionType | : | OPTIONAL IfcStrippedOptional;

| ENTITY IfcSpace

PredefinedType | : | OPTIONAL IfcStrippedOptional;
ElevationWithFlooring | : | OPTIONAL IfcStrippedOptional;

| INVERSE

END_ENTITY;

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