Chimneys are typically vertical, or as near as vertical, parts of the construction of a building and part of the building fabric. Often constructed by pre-cast or insitu concrete, today seldom by bricks.

NOTE  Definition according to ISO 6707-1: construction containing one or more flues.
Flue: Duct designed to convey the products of combustion to the open air.
Chimney stack: Part of the chimney that projects above a roof.
HISTORY  New entity in IFC4.

Common Use Definitions

The following concepts are inherited at supertypes:

 Instance diagram

Object Typing

The Object Typing concept applies to this entity as shown in Table 96.

Table 96 — IfcChimney Object Typing

Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 97.

Table 97 — IfcChimney Property Sets for Objects

Quantity Sets

The Quantity Sets concept applies to this entity as shown in Table 98.

Table 98 — IfcChimney Quantity Sets

Spatial Containment

The Spatial Containment concept applies to this entity as shown in Table 99.
IfcBuildingStoreyDefault spatial container (in most cases the storey where the base of the chimney is placed)
IfcBuildingSpatial container for the element if it cannot be assigned to a building storey
IfcSiteSpatial container for the element in case that it is placed on site (outside of building)

Table 99 — IfcChimney Spatial Containment

The IfcChimney, as any subtype of IfcBuildingElement, may participate alternatively in one of the two different containment relationships:

XSD Specification:

 <xs:element name="IfcChimney" type="ifc:IfcChimney" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>
 <xs:complexType name="IfcChimney">
   <xs:extension base="ifc:IfcBuildingElement">
    <xs:attribute name="PredefinedType" type="ifc:IfcChimneyTypeEnum" use="optional"/>

EXPRESS Specification:

ENTITY IfcChimney
SUBTYPE OF IfcBuildingElement;
PredefinedType : OPTIONAL IfcChimneyTypeEnum;
CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcChimneyTypeEnum.USERDEFINED) OR ((PredefinedType = IfcChimneyTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
CorrectTypeAssigned : (SIZEOF(IsTypedBy) = 0) OR ('IFCSHAREDBLDGELEMENTS.IFCCHIMNEYTYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));

Link to EXPRESS-G diagram EXPRESS-G diagram

Attribute Definitions:

PredefinedType : Predefined generic type for a chimney that is specified in an enumeration. There may be a property set given specificly for the predefined types.
NOTE  The PredefinedType shall only be used, if no IfcChimneyType is assigned, providing its own IfcChimneyType.PredefinedType.

Formal Propositions:

CorrectPredefinedType : Either the PredefinedType attribute is unset (e.g. because an IfcChimneyType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.
CorrectTypeAssigned : Either there is no chimney type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcChimneyType.

Inheritance Graph:

ENTITY IfcChimney
GlobalId : IfcGloballyUniqueId;
OwnerHistory : OPTIONAL IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcText;
ENTITY IfcObjectDefinition
HasAssignments : SET OF IfcRelAssigns FOR RelatedObjects;
Nests : SET [0:1] OF IfcRelNests FOR RelatedObjects;
IsNestedBy : SET OF IfcRelNests FOR RelatingObject;
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 IfcLabel;
IsDeclaredBy : SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects;
Declares : SET OF IfcRelDefinesByObject FOR RelatingObject;
IsTypedBy : SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects;
IsDefinedBy : SET OF IfcRelDefinesByProperties FOR RelatedObjects;
ENTITY IfcProduct
ObjectPlacement : OPTIONAL IfcObjectPlacement;
Representation : OPTIONAL IfcProductRepresentation;
ReferencedBy : SET OF IfcRelAssignsToProduct FOR RelatingProduct;
ENTITY IfcElement
Tag : OPTIONAL IfcIdentifier;
FillsVoids : SET [0:1] OF IfcRelFillsElement FOR RelatedBuildingElement;
ConnectedTo : SET OF IfcRelConnectsElements FOR RelatingElement;
IsInterferedByElements : SET OF IfcRelInterferesElements FOR RelatedElement;
InterferesElements : SET OF IfcRelInterferesElements FOR RelatingElement;
HasProjections : SET OF IfcRelProjectsElement FOR RelatingElement;
ReferencedInStructures : SET OF IfcRelReferencedInSpatialStructure FOR RelatedElements;
HasOpenings : SET OF IfcRelVoidsElement FOR RelatingBuildingElement;
IsConnectionRealization : SET OF IfcRelConnectsWithRealizingElements FOR RealizingElements;
ProvidesBoundaries : SET OF IfcRelSpaceBoundary FOR RelatedBuildingElement;
ConnectedFrom : SET OF IfcRelConnectsElements FOR RelatedElement;
ContainedInStructure : SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements;
ENTITY IfcBuildingElement
HasCoverings : SET OF IfcRelCoversBldgElements FOR RelatingBuildingElement;
ENTITY IfcChimney
PredefinedType : OPTIONAL IfcChimneyTypeEnum;

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