IfcBuildingSystem

Natural language names
Bauliches System
Building System
Système
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcBuildingSystemADDED
IFC4 Addendum 1
    IfcBuildingSystem
      LongNameADDED
Semantic definitions at the entity
Entity definition

A building system is a group by which building elements are grouped according to a common function within the building.

The group IfcBuildingSystem defines the occurrence of a specialized system for use within the context of a building and finishing fabric. Important functionalities for the description of a building system are derived from supertypes:

HISTORY  New entity in IFC4.
Attribute definitions
#AttributeTypeCardinalityDescription G
6PredefinedTypeIfcBuildingSystemTypeEnum? Predefined types of distribution systems.X
7LongNameIfcLabel? Long name for a building system, 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 building system, and the LongName refers to a descriptive name.
X
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
IfcBuildingSystem
6PredefinedTypeIfcBuildingSystemTypeEnum? Predefined types of distribution systems.X
7LongNameIfcLabel? Long name for a building system, 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 building system, and the LongName refers to a descriptive name.
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 92.

PsetNameProperties
Pset_BuildingSystemCommon
TemplatePropertyNameValue
Single ValueReferenceIfcIdentifier
Pset_ServiceLifeFactors
TemplatePropertyNameUpperValueLowerValueSetValue
Bounded ValueQualityOfComponentsIfcPositiveRatioMeasure
Bounded ValueDesignLevelIfcPositiveRatioMeasure
Bounded ValueWorkExecutionLevelIfcPositiveRatioMeasure
Bounded ValueIndoorEnvironmentIfcPositiveRatioMeasure
Bounded ValueOutdoorEnvironmentIfcPositiveRatioMeasure
Bounded ValueInUseConditionsIfcPositiveRatioMeasure
Bounded ValueMaintenanceLevelIfcPositiveRatioMeasure

Table 92 — IfcBuildingSystem Property Sets for Objects



Aggregation

The Aggregation concept template applies to this entity as shown in Table 93.

Table 93 — IfcBuildingSystem Aggregation



Group Assignment

The Group Assignment concept template applies to this entity as shown in Table 94.

IsGroupedRelatedObjectsDescription
Building elements participating in the building system.

Table 94 — IfcBuildingSystem Group Assignment



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="751a08d2-7822-4fce-9a0c-0f5135e4f1a8" name="IfcBuildingSystem" status="sample" applicableRootEntity="IfcBuildingSystem">
  <Applicability uuid="00000000-0000-0000-0000-000000000000" status="sample">
    <Template ref="1dfe9929-d448-40d7-98a6-9a535bf238cc" />
    <TemplateRules operator="and" />
  </Applicability>
  <Concepts>
    <Concept uuid="ba7f03c2-21c3-45d6-b863-571d9e6b7923" name="Property Sets for Objects" status="sample" override="false">
      <Template ref="f74255a6-0c0e-4f31-84ad-24981db62461" />
      <TemplateRules operator="and">
        <TemplateRule Parameters="PsetName[Value]='Pset_BuildingSystemCommon'" />
      </TemplateRules>
    </Concept>
    <Concept uuid="8ff8be1d-483a-4a5b-ab2f-89f29c67ad67" name="Aggregation" status="sample" override="false">
      <Template ref="02eefcc6-b26c-4f20-9c7c-c30ae74eb9a9" />
      <TemplateRules operator="and">
        <TemplateRule Description=" Building systems may be aggregated into subsystems." Parameters="" />
      </TemplateRules>
    </Concept>
    <Concept uuid="0a2edab8-d715-4d71-aa78-a5c61a916f27" name="Group Assignment" status="sample" override="false">
      <Template ref="f567967f-5493-44d9-ac51-937c09ac2583" />
      <TemplateRules operator="and">
        <TemplateRule Description="Building elements participating in the building system." 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
IfcBuildingSystem
Property Sets for ObjectsProperty Sets for ObjectsGeneral Usage
AggregationAggregationGeneral Usage
Group AssignmentGroup AssignmentGeneral Usage
Formal representations
XML Specification
 <xs:element name="IfcBuildingSystem" type="ifc:IfcBuildingSystem" substitutionGroup="ifc:IfcSystem" nillable="true"/>
 <xs:complexType name="IfcBuildingSystem">
  <xs:complexContent>
   <xs:extension base="ifc:IfcSystem">
    <xs:attribute name="PredefinedType" type="ifc:IfcBuildingSystemTypeEnum" use="optional"/>
    <xs:attribute name="LongName" type="ifc:IfcLabel" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcBuildingSystem
 SUBTYPE OF (IfcSystem);
  PredefinedType : OPTIONAL IfcBuildingSystemTypeEnum;
  LongName : OPTIONAL IfcLabel;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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