IfcZone

Natural language names
Zone
Zone
Zone
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcZone
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      LongNameADDED
Semantic definitions at the entity
Entity definition

A zone is a group of spaces, partial spaces or other zones. Zone structures may not be hierarchical (in contrary to the spatial structure of a project - see IfcSpatialStructureElement), i.e. one individual IfcSpace may be associated with zero, one, or several IfcZone's. IfcSpace's are grouped into an IfcZone by using the objectified relationship IfcRelAssignsToGroup as specified at the supertype IfcGroup.

NOTE  Certain use cases may restrict the freedom of non hierarchical relationships. In some building service use cases the zone denotes a view based delimited volume for the purpose of analysis and calculation. This type of zone cannot overlap with respect to that analysis, but may overlap otherwise.
HISTORY  New entity in IFC1.0
IFC4 CHANGE  The entity is now subtyped from IfcSystem (not its supertype IfcGroup) with upward compatibility for file based exchange.
Attribute definitions
#AttributeTypeCardinalityDescription G
6LongNameIfcLabel? Long name for a zone, used for informal purposes. It should be used, if available, in conjunction with the inherited Name attribute.
NOTE  In many scenarios the Name attribute refers to the short name or number of a zone, and the LongName refers to the full name.

IFC4 CHANGE The attribute has been added at the end of the entity definition.
X
Formal Propositions
RuleDescription
WR1An IfcZone is grouped by the objectified relationship IfcRelAssignsToGroup. Only objects of type IfcSpace, IfcZone and IfcSpatialZone are allowed as RelatedObjects.
Inherited definitions from supertypes
Entity inheritance IfcSystem IfcGroup IfcObject IfcObjectDefinition IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcRoot
1GlobalIdIfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory? Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object,
NOTE  only the last modification in stored - either as addition, deletion or modification.
IFC4 CHANGE  The attribute has been changed to be OPTIONAL.
X
3NameIfcLabel? Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule. X
4DescriptionIfcText? Optional description, provided for exchanging informative comments.X
IfcObjectDefinition
HasAssignmentsIfcRelAssigns
@RelatedObjects
S[0:?]Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups.X
NestsIfcRelNests
@RelatedObjects
S[0:1]References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only).
IFC4 CHANGE  The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
X
IsNestedByIfcRelNests
@RelatingObject
S[0:?]References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types).
IFC4 CHANGE  The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
X
HasContextIfcRelDeclares
@RelatedDefinitions
S[0:1]References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object.
IFC4 CHANGE  The inverse attribute datatype has been added.
X
IsDecomposedByIfcRelAggregates
@RelatingObject
S[0:?]References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts).
IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
X
DecomposesIfcRelAggregates
@RelatedObjects
S[0:1]References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only).
IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
X
HasAssociationsIfcRelAssociates
@RelatedObjects
S[0:?]Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification.X
IfcObject
5ObjectTypeIfcLabel? The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED.
X
IsDeclaredByIfcRelDefinesByObject
@RelatedObjects
S[0:1]Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
X
DeclaresIfcRelDefinesByObject
@RelatingObject
S[0:?]Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
X
IsTypedByIfcRelDefinesByType
@RelatedObjects
S[0:1]Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type.
IFC4 CHANGE  New inverse relationship, the link to IfcRelDefinesByType had previously be included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
X
IsDefinedByIfcRelDefinesByProperties
@RelatedObjects
S[0:?]Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object.
IFC4 CHANGE  The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.
X
IfcGroup
IsGroupedByIfcRelAssignsToGroup
@RelatingGroup
S[0:?]Reference to the relationship IfcRelAssignsToGroup that assigns the one to many group members to the IfcGroup object.
IFC4 CHANGE  The cardinality has been changed from 1..1 to 0..? in order to allow the exchange of a group concept without having already group members assigned. It now also allows the use of many instances of IfcRelAssignsToGroup to assign the group members. The change has been done with upward compatibility for file based exchange.
X
IfcSystem
ServicesBuildingsIfcRelServicesBuildings
@RelatingSystem
S[0:1]Reference to the building spatial structure via the objectified relationship IfcRelServicesBuildings, which is serviced by the system. X
IfcZone
6LongNameIfcLabel? Long name for a zone, used for informal purposes. It should be used, if available, in conjunction with the inherited Name attribute.
NOTE  In many scenarios the Name attribute refers to the short name or number of a zone, and the LongName refers to the full name.

IFC4 CHANGE The attribute has been added at the end of the entity definition.
X
Definitions applying to General Usage

 Instance diagram


Concept usage

Property Sets for Objects

The Property Sets for Objects concept template applies to this entity as shown in Table 91.

PsetNameProperties
Pset_ZoneCommon
TemplatePropertyNameValue
Single ValueReferenceIfcIdentifier
Single ValueIsExternalIfcBoolean
Single ValueGrossPlannedAreaIfcAreaMeasure
Single ValueNetPlannedAreaIfcAreaMeasure
Single ValuePubliclyAccessibleIfcBoolean
Single ValueHandicapAccessibleIfcBoolean
Pset_AirSideSystemInformation
TemplatePropertyNameValueReference
Single ValueNameIfcLabel
Single ValueDescriptionIfcLabel
Single ValueTotalAirflowIfcVolumetricFlowRateMeasure
Single ValueEnergyGainTotalIfcPowerMeasure
Single ValueAirflowSensibleIfcVolumetricFlowRateMeasure
Single ValueEnergyGainSensibleIfcPowerMeasure
Single ValueEnergyLossIfcPowerMeasure
Single ValueLightingDiversityIfcPositiveRatioMeasure
Single ValueInfiltrationDiversitySummerIfcPositiveRatioMeasure
Single ValueInfiltrationDiversityWinterIfcPositiveRatioMeasure
Single ValueApplianceDiversityIfcPositiveRatioMeasure
Single ValueLoadSafetyFactorIfcPositiveRatioMeasure
Single ValueHeatingTemperatureDeltaIfcThermodynamicTemperatureMeasure
Single ValueCoolingTemperatureDeltaIfcThermodynamicTemperatureMeasure
Single ValueVentilationIfcVolumetricFlowRateMeasure
Single ValueFanPowerIfcPowerMeasure
Enumerated ValueAirSideSystemTypeIfcLabel
Enumerated ValueAirSideSystemDistributionTypeIfcLabel

Table 91 — IfcZone Property Sets for Objects



Group Assignment

The Group Assignment concept template applies to this entity as shown in Table 92.

IsGroupedRelatedObjects

Table 92 — IfcZone Group Assignment

An IfcZone is a spatial system under which individual IfcSpace's (and other IfcZone's) are grouped. In contrary to the IfcSpatialZone entity, IfcZone is a mere grouping, it can not define an own geometric representation and placement. Therefore it cannot be used for spatial zones having a different shape and size compared to the shape and size of aggregated spaces.

NOTE  The IfcZone is regarded as the spatial system (as compared to the building service, electrical, or analytical system), the name remains IfcZone for compatibility reasons, instead of using a proper naming convention, like IfcSpatialSystem.
NOTE  One of the purposes of a zone is to define a fire compartmentation. In this case it defines the geometric information about the fire compartment (through the contained spaces) and information, whether this compartment is ventilated or sprinkler protected. In addition the fire risk code and the hazard type can be added, the coding is normally defined within a national fire regulation. All that information is available within the relevant property sets. Again, if an independent shape has to be provided to the fire compartment, then the entity IfcSpatialZone shall be used.

In case of a zone denoting a (fire) compartment, the following types should be used, if applicable, as values of the ObjectType attribute:



mvdXML Specification
<?xml version="1.0"?>
<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" uuid="d40ff8d5-1a6b-4136-9896-ce77d527148b" name="IfcZone" status="sample" applicableRootEntity="IfcZone">
  <Applicability uuid="00000000-0000-0000-0000-000000000000" status="sample">
    <Template ref="e2b91f1e-dd4b-459a-b17a-9689d20b46b0" />
    <TemplateRules operator="and" />
  </Applicability>
  <Concepts>
    <Concept uuid="f43eec38-fced-4f78-af1d-fadfe7e37719" name="Property Sets for Objects" status="sample" override="false">
      <Template ref="f74255a6-0c0e-4f31-84ad-24981db62461" />
      <TemplateRules operator="and">
        <TemplateRule Parameters="PsetName[Value]='Pset_ZoneCommon'" />
        <TemplateRule Parameters="PsetName[Value]='Pset_AirSideSystemInformation'" />
      </TemplateRules>
    </Concept>
    <Concept uuid="10921e37-76da-4d53-9bf6-a11a04ac9432" name="Group Assignment" status="sample" override="false">
      <Template ref="f567967f-5493-44d9-ac51-937c09ac2583" />
      <TemplateRules operator="and">
        <TemplateRule Parameters="" />
      </TemplateRules>
    </Concept>
  </Concepts>
</ConceptRoot>
Concept inheritance

#ConceptTemplateModel View
IfcRoot
IdentitySoftware IdentityGeneral Usage
Revision ControlRevision ControlGeneral Usage
IfcObjectDefinition
Classification AssociationClassification AssociationGeneral Usage
IfcObject
Object User IdentityObject User IdentityGeneral Usage
Object Predefined TypeObject Predefined TypeGeneral Usage
Object TypingObject TypingGeneral Usage
Property Sets with OverrideProperty Sets with OverrideGeneral Usage
IfcZone
Property Sets for ObjectsProperty Sets for ObjectsGeneral Usage
Group AssignmentGroup AssignmentGeneral Usage
Formal representations
XML Specification
 <xs:element name="IfcZone" type="ifc:IfcZone" substitutionGroup="ifc:IfcSystem" nillable="true"/>
 <xs:complexType name="IfcZone">
  <xs:complexContent>
   <xs:extension base="ifc:IfcSystem">
    <xs:attribute name="LongName" type="ifc:IfcLabel" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcZone
 SUBTYPE OF (IfcSystem);
  LongName : OPTIONAL IfcLabel;
 WHERE
  WR1 : (SIZEOF(SELF\IfcGroup.IsGroupedBy) = 0) OR
 (SIZEOF (QUERY (temp <* SELF\IfcGroup.IsGroupedBy[1].RelatedObjects |
  NOT(('IFCPRODUCTEXTENSION.IfcZone' IN TYPEOF(temp)) OR
  ('IFCPRODUCTEXTENSION.IfcSpace' IN TYPEOF(temp)) OR
  ('IFCPRODUCTEXTENSION.IfcSpatialZone' IN TYPEOF(temp))
 ))) = 0);
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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