IfcBuilding

Item	Change	Description
IFC2x3 to IFC4
IfcBuilding
OwnerHistory	MODIFIED	Instantiation changed to OPTIONAL.
CompositionType	MODIFIED	Instantiation changed to OPTIONAL.

#	Attribute	Type	Cardinality	Description	C
10	ElevationOfRefHeight	IfcLengthMeasure	[0:1]	Elevation above sea level of the reference height used for all storey elevation measures, equals to height 0.0. It is usually the ground floor level.	X
11	ElevationOfTerrain	IfcLengthMeasure	[0:1]	Elevation above the minimal terrain level around the foot print of the building, given in elevation above sea level.	X
12	BuildingAddress	IfcPostalAddress	[0:1]	Address given to the building for postal purposes.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcRoot
1	GlobalId	IfcGloballyUniqueId	[1:1]	Assignment of a globally unique identifier within the entire software world.	X
2	OwnerHistory	IfcOwnerHistory	[0:1]	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.	X
3	Name	IfcLabel	[0:1]	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
4	Description	IfcText	[0:1]	Optional description, provided for exchanging informative comments.	X
IfcObjectDefinition
	HasAssignments	IfcRelAssigns @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
	Nests	IfcRelNests @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).	X
	IsNestedBy	IfcRelNests @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).	X
	HasContext	IfcRelDeclares @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.	X
	IsDecomposedBy	IfcRelAggregates @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).	X
	Decomposes	IfcRelAggregates @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).	X
	HasAssociations	IfcRelAssociates @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
5	ObjectType	IfcLabel	[0:1]	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
	IsDeclaredBy	IfcRelDefinesByObject @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.	X
	Declares	IfcRelDefinesByObject @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.	X
	IsTypedBy	IfcRelDefinesByType @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.	X
	IsDefinedBy	IfcRelDefinesByProperties @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.	X
IfcProduct
6	ObjectPlacement	IfcObjectPlacement	[0:1]	Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system.	X
7	Representation	IfcProductRepresentation	[0:1]	Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement.	X
	ReferencedBy	IfcRelAssignsToProduct @RelatingProduct	S[0:?]	Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product.	X
IfcSpatialElement
8	LongName	IfcLabel	[0:1]	Long name for a spatial structure element, 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 spacial element, and the LongName refers to the full descriptive name.	X
	ContainsElements	IfcRelContainedInSpatialStructure @RelatingStructure	S[0:?]	Set of spatial containment relationships, that holds those elements, which are contained within this element of the project spatial structure. NOTE The spatial containment relationship, established by IfcRelContainedInSpatialStructure, is required to be an hierarchical relationship, where each element can only be assigned to 0 or 1 spatial structure element.	X
	ServicedBySystems	IfcRelServicesBuildings @RelatedBuildings	S[0:?]	Set of relationships to systems, that provides a certain service to the spatial element for which it is defined. The relationship is handled by the objectified relationship IfcRelServicesBuildings.	X
	ReferencesElements	IfcRelReferencedInSpatialStructure @RelatingStructure	S[0:?]	Set of spatial reference relationships, that holds those elements, which are referenced, but not contained, within this element of the project spatial structure. NOTE The spatial reference relationship, established by IfcRelReferencedInSpatialStructure, is not required to be an hierarchical relationship, i.e. each element can be assigned to 0, 1 or many spatial structure elements. EXAMPLE A curtain wall maybe contained in the ground floor, but maybe referenced in all floors, it reaches. Ø\X	X
IfcSpatialStructureElement
9	CompositionType	IfcElementCompositionEnum	[0:1]	Denotes, whether the predefined spatial structure element represents itself, or an aggregate (complex) or a part (part). The interpretation is given separately for each subtype of spatial structure element. If no CompositionType is asserted, the dafault value 'ELEMENT' applies.	X
IfcBuilding
10	ElevationOfRefHeight	IfcLengthMeasure	[0:1]	Elevation above sea level of the reference height used for all storey elevation measures, equals to height 0.0. It is usually the ground floor level.	X
11	ElevationOfTerrain	IfcLengthMeasure	[0:1]	Elevation above the minimal terrain level around the foot print of the building, given in elevation above sea level.	X
12	BuildingAddress	IfcPostalAddress	[0:1]	Address given to the building for postal purposes.	X

Definitions applying to Common Use Definitions

Instance diagram

Concept usage

Spatial Composition

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

Spatial Composite	Description
IfcProject	Direct assignment to project, if the building is the outermost spatial container, and no site information is provided for building projects
IfcSite	Assignment to site, if the building is the spatial container for the building project with site information
IfcBuilding	Assignment to another building as spatial container, e.g. if this building represents a building section.

Table 23 — IfcBuilding Spatial Composition

NOTE By using the inverse relationship IfcBuilding.Decomposes it references IfcProject || IfcSite || IfcBuilding through IfcRelAggregates.RelatingObject. If it refers to another instance of IfcBuilding, the referenced IfcBuilding needs to have a different and higher CompositionType, i.e. COMPLEX (if the other IfcBuilding has ELEMENT), or ELEMENT (if the other IfcBuilding has PARTIAL).

Spatial Decomposition

The Spatial Decomposition concept applies to this entity as shown in Table 24.

Spatial Parts	Description
IfcBuildingStorey	Spatial decomposition into building stories.
IfcBuilding	Spatial decomposition into other buildings, e.g. if this building represents a complex building that is subdivided into building sections.

Table 24 — IfcBuilding Spatial Decomposition

NOTE By using the inverse relationship IfcBuilding.IsDecomposedBy it references IfcBuilding || IfcBuildingStorey through IfcRelAggregates.RelatedObjects. If it refers to another instance of IfcBuilding, the referenced IfcBuilding needs to have a different and lower CompositionType, i.e. ELEMENT (if the other IfcBuilding has COMPLEX), or PARTIAL (if the other IfcBuilding has ELEMENT).

Spatial Container

The Spatial Container concept applies to this entity as shown in Table 25.

Type	Description
	Physical elements contained in the building.

Table 25 — IfcBuilding Spatial Container

NOTE If there are building elements and/or other elements directly related to the IfcBuilding (like a curtain wall spanning several stories), they are associated with the IfcBuilding by using the objectified relationship IfcRelContainedInSpatialStructure. The IfcBuilding references them by its inverse relationship:

IfcBuilding.ContainsElements -- referencing any subtype of IfcProduct (with the exception of other spatial structure element) by IfcRelContainedInSpatialStructure.RelatedElements.

Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 26.

PredefinedType

Name

Properties

Pset_BuildingCommon

Single Value

Name	Value
Reference	IfcIdentifier
BuildingID	IfcIdentifier
IsPermanentID	IfcBoolean
ConstructionMethod	IfcLabel
FireProtectionClass	IfcLabel
SprinklerProtection	IfcBoolean
SprinklerProtectionAutomatic	IfcBoolean
OccupancyType	IfcLabel
GrossPlannedArea	IfcAreaMeasure
NetPlannedArea	IfcAreaMeasure
NumberOfStoreys	IfcInteger
YearOfConstruction	IfcLabel
YearOfLastRefurbishment	IfcLabel
IsLandmarked	IfcLogical

Pset_BuildingUse

Single Value

Name	Value
MarketCategory	IfcLabel
MarketSubCategory	IfcLabel
PlanningControlStatus	IfcLabel
NarrativeText	IfcText
VacancyRateInCategoryNow	IfcPositiveRatioMeasure
VacancyRateInCategoryFuture	IfcPositiveRatioMeasure

Bounded Value

Name	Value	Value
RentalRatesInCategoryNow	IfcMonetaryMeasure	IfcMonetaryMeasure
RentalRatesInCategoryFuture	IfcMonetaryMeasure	IfcMonetaryMeasure

Pset_BuildingUseAdjacent

Single Value

Name	Value
MarketCategory	IfcLabel
MarketSubCategory	IfcLabel
PlanningControlStatus	IfcLabel
NarrativeText	IfcText

Pset_OutsideDesignCriteria

Single Value

Name	Value
HeatingDryBulb	IfcThermodynamicTemperatureMeasure
HeatingWetBulb	IfcThermodynamicTemperatureMeasure
HeatingDesignDay	IfcDateTime
CoolingDryBulb	IfcThermodynamicTemperatureMeasure
CoolingWetBulb	IfcThermodynamicTemperatureMeasure
CoolingDesignDay	IfcDateTime
WeatherDataStation	IfcText
WeatherDataDate	IfcDateTime
PrevailingWindDirection	IfcPlaneAngleMeasure
PrevailingWindVelocity	IfcLinearVelocityMeasure

Enumerated Value

Name	Value	Value
BuildingThermalExposure	IfcLabel	IfcLabel

Pset_PropertyAgreement

Single Value

Name	Value
Identifier	IfcIdentifier
Version	IfcLabel
VersionDate	IfcDate
PropertyName	IfcLabel
CommencementDate	IfcDate
TerminationDate	IfcDate
Duration	IfcDuration
Options	IfcText
ConditionCommencement	IfcText
Restrictions	IfcText
ConditionTermination	IfcText

Enumerated Value

Name	Value	Value
AgreementType	IfcLabel	IfcLabel

Pset_ThermalLoadAggregate

Single Value

Name	Value
TotalCoolingLoad	IfcPowerMeasure
TotalHeatingLoad	IfcPowerMeasure
LightingDiversity	IfcPositiveRatioMeasure
InfiltrationDiversitySummer	IfcPositiveRatioMeasure
InfiltrationDiversityWinter	IfcPositiveRatioMeasure
ApplianceDiversity	IfcPositiveRatioMeasure
LoadSafetyFactor	IfcPositiveRatioMeasure

Pset_ThermalLoadDesignCriteria

Single Value

Name	Value
OccupancyDiversity	IfcPositiveRatioMeasure
OutsideAirPerPerson	IfcVolumetricFlowRateMeasure
ReceptacleLoadIntensity	IfcReal
AppliancePercentLoadToRadiant	IfcPositiveRatioMeasure
LightingLoadIntensity	IfcReal
LightingPercentLoadToReturnAir	IfcPositiveRatioMeasure

Table 26 — IfcBuilding Property Sets for Objects

Quantity Sets

The Quantity Sets concept applies to this entity as shown in Table 27.

Name
Qto_BuildingBaseQuantities

Table 27 — IfcBuilding Quantity Sets

Product Local Placement

The Product Local Placement concept applies to this entity.

The local placement for IfcBuilding is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.

The PlacementRelTo relationship of IfcLocalPlacement shall point (if relative placement is used) to the IfcSpatialStructureElement of type IfcSite, or of type IfcBuilding (e.g. to position a building relative to a building complex, or a building section to a building).
If the relative placement is not used, the absolute placement is defined within the world coordinate system.

FootPrint GeomSet Geometry

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

Identifier	Type	Items	Description
FootPrint	GeometricCurveSet	IfcGeometricCurveSet	Set of curves (outer and inner) representing the floor projection,

Table 28 — IfcBuilding FootPrint GeomSet Geometry

The foot print representation of IfcBuilding is given by either a single 2D curve (such as IfcPolyline or IfcCompositeCurve), or by a list of 2D curves (in case of inner boundaries), if the building has an independent geometric representation.

NOTE The independent geometric representation of IfcBuilding may not be allowed in certain model view definitions. In those cases only the contained elements and spaces have an independent geometric representation.

Body Geometry

The Body Geometry concept applies to this entity.

The body (or solid model) geometric representation (if the building has an independent geometric representation) of IfcBuilding is defined using faceted B-Rep capabilities (with or without voids), based on the IfcFacetedBrep or on the IfcFacetedBrepWithVoids.

NOTE Since the building shape is usually described by the exterior building elements, an independent shape representation shall only be given, if the building is exposed independently from its constituting elements and such independent geometric representation may be prohibited in model view definitions.

Concept inheritance

#	Concept	Model View
IfcRoot
	Software Identity	Common Use Definitions
	Revision Control	Common Use Definitions
IfcObject
	Object Occurrence Predefined Type	Common Use Definitions
IfcSpatialElement
IfcSpatialStructureElement
IfcBuilding
	Spatial Composition	Common Use Definitions
	Spatial Decomposition	Common Use Definitions
	Spatial Container	Common Use Definitions
	Property Sets for Objects	Common Use Definitions
	Quantity Sets	Common Use Definitions
	Product Local Placement	Common Use Definitions
	FootPrint GeomSet Geometry	Common Use Definitions
	Body Geometry	Common Use Definitions

Formal representations

XSD Specification

 <xs:element name="IfcBuilding" type="ifc:IfcBuilding" substitutionGroup="ifc:IfcSpatialStructureElement" nillable="true"/>

 <xs:complexType name="IfcBuilding">

  <xs:complexContent>

   <xs:extension base="ifc:IfcSpatialStructureElement">

    <xs:sequence>

     <xs:element name="BuildingAddress" type="ifc:IfcPostalAddress" nillable="true" minOccurs="0"/>

    </xs:sequence>

    <xs:attribute name="ElevationOfRefHeight" type="ifc:IfcLengthMeasure" use="optional"/>

    <xs:attribute name="ElevationOfTerrain" type="ifc:IfcLengthMeasure" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcBuilding

 SUBTYPE OF (IfcSpatialStructureElement);

  ElevationOfRefHeight : OPTIONAL IfcLengthMeasure;

  ElevationOfTerrain : OPTIONAL IfcLengthMeasure;

  BuildingAddress : OPTIONAL IfcPostalAddress;

END_ENTITY;

 EXPRESS-G diagram

Link to this page

	Gebäude
	Building
	Bâtiment

IfcBuilding

Semantic definitions at the entity

Inherited definitions from supertypes

Definitions applying to Common Use Definitions

Formal representations