5.4.3.63 IfcSite

5.4.3.63.1 Semantic definition

A site is a defined area of land, possibly covered with water, on which the project construction is to be completed. A site may be used to erect, retrofit or turn down building(s), or for other construction related developments.

Precise geospatial information of a site shall be derived from the georeferencing entities that relate the IfcProject to the real world, using sets of datum (see IfcCoordinateOperation and IfcCoordinateReferenceSystem).

In small-scale projects (e.g., building), when georeferencing is not provided as recommended above, the Longitude, Latitude and Elevation attributes of IfcSite can be used for approximate indication of the site location. This methodology is not meant to replace precise georeferencing, but can still be useful for those use cases that do not require accurate geospatial information (e.g., sun shading simulations). If asserted, the Longitude, Latitude and Elevation establish the point in WGS84 where the point 0.,0.,0. of the LocalPlacement of IfcSite is situated.

The geometrical placement of the site, defined by the IfcLocalPlacement, shall be always relative to the spatial structure element, in which this site is included, or absolute, i.e. to the world coordinate system, as established by the geometric representation context of the project. The world coordinate system, established at the IfcProject.RepresentationContexts, may include a definition of the true north within the XY plane of the world coordinate system, if provided, it can be obtained at IfcGeometricRepresentationContext.TrueNorth.

A project may span over several connected or disconnected sites. Therefore site complex provides for a collection of sites included in a project. A site can also be decomposed in parts, where each part defines a site section. This is defined by the composition type attribute of the supertype IfcSpatialStructureElement which is interpreted as follow:

• COMPLEX = site complex
• ELEMENT = site
• PARTIAL = site section

Figure 5.4.3.63.A shows the IfcSite as part of the spatial structure. In addition to the logical spatial structure, also the placement hierarchy is shown. In this example the spatial structure hierarchy and the placement hierarchy are identical.

Figure 5.4.3.63.B describes the heights and elevations of the IfcSite. It is used to provide the geographic longitude, latitude, and height above sea level for the origin of the site. The origin of the site is the local placement.

The provision of longitude, latitude, height at the IfcSite for georeferencing is provided for upward compatibility reasons. It requires a single instance of IfcSite and WGS84 as coordinate reference system.

For exact georeferencing (or referencing to any other geographic coordinate system other than WSG84) the entities IfcCoordinateReferenceSystem and IfcMapConversion have to be used to define an exact mapping of the project engineering coordinate system to the geographic (or map) coordinate system.

• reference height of site is provided by: IfcSite.RefElevation, it is given according to the height datum used at this location.
• the reference height of each building situated at the site is given against the same height datum used at this location.
• the elevations of each storey belonging to each building are given as local height relative to the reference height of the building.

5.4.3.63.2 Entity inheritance

1. • IfcRoot
2. • IfcObjectDefinition
   • IfcPropertyDefinition
   • IfcRelationship
3. • IfcObject
   • IfcContext
   • IfcTypeObject
4. • IfcProduct
   • IfcActor
   • IfcControl
   • IfcGroup
   • IfcProcess
   • IfcResource
5. • IfcSpatialElement
   • IfcAnnotation
   • IfcElement
   • IfcLinearElement
   • IfcPort
   • IfcPositioningElement
   • IfcStructuralActivity
   • IfcStructuralItem
6. • IfcSpatialStructureElement
   • IfcExternalSpatialStructureElement
   • IfcSpatialZone
7. • IfcSite
   • IfcBuildingStorey
   • IfcFacility
   • IfcFacilityPart
   • IfcSpace

5.4.3.63.3 Attributes

#	Attribute	Type	Description
IfcRoot (4)
1	GlobalId	IfcGloballyUniqueId	Assignment of a globally unique identifier within the entire software world.
2	OwnerHistory	OPTIONAL IfcOwnerHistory	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,
3	Name	OPTIONAL IfcLabel	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.
4	Description	OPTIONAL IfcText	Optional description, provided for exchanging informative comments.
IfcObjectDefinition (7)
	HasAssignments	SET [0:?] OF IfcRelAssigns FOR RelatedObjects	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.
	Nests	SET [0:1] OF IfcRelNests FOR RelatedObjects	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 structures only).
	IsNestedBy	SET [0:?] OF IfcRelNests FOR RelatingObject	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).
	HasContext	SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions	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.
	IsDecomposedBy	SET [0:?] OF IfcRelAggregates FOR RelatingObject	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 definition can be aggregated by several other objects (occurrences or parts).
	Decomposes	SET [0:1] OF IfcRelAggregates FOR RelatedObjects	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 definition can only be part of a single decomposition (to allow hierarchical structures only).
	HasAssociations	SET [0:?] OF IfcRelAssociates FOR RelatedObjects	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.
IfcObject (5)
5	ObjectType	OPTIONAL IfcLabel	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 or when the concrete entity instantiated does not have a PredefinedType attribute. The latter is the case in some exceptional leaf classes and when instantiating IfcBuiltElement directly.
	IsDeclaredBy	SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects	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.
	Declares	SET [0:?] OF IfcRelDefinesByObject FOR RelatingObject	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.
	IsTypedBy	SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects	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.
	IsDefinedBy	SET [0:?] OF IfcRelDefinesByProperties FOR RelatedObjects	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.
IfcProduct (5)
6	ObjectPlacement	OPTIONAL IfcObjectPlacement	This establishes the object coordinate system and 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 constrained (e.g. relative to grid axes, or to a linear positioning element). The type of placement is determined by the various subtypes of IfcObjectPlacement. An object placement must be provided if a representation is present.
7	Representation	OPTIONAL IfcProductRepresentation	Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case of a shape representation (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.
	ReferencedBy	SET [0:?] OF IfcRelAssignsToProduct FOR RelatingProduct	Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product.
	PositionedRelativeTo	SET [0:?] OF IfcRelPositions FOR RelatedProducts	Reference to the IfcRelPositions relationship, which defines its relationship with a positioning element.
	ReferencedInStructures	SET [0:?] OF IfcRelReferencedInSpatialStructure FOR RelatedElements	Reference to the objectified relationship IfcRelReferencedInSpatialStructure may be used to relate a product to one or more spatial structure elements in addition to the one in which it is primarily contained.
IfcSpatialElement (6)
8	LongName	OPTIONAL IfcLabel	Long name for a spatial structure element, used for informal purposes. It should be used, if available, in conjunction with the inherited Name attribute.
	ContainsElements	SET [0:?] OF IfcRelContainedInSpatialStructure FOR RelatingStructure	Set of spatial containment relationships, that holds those elements, which are contained within this element of the project spatial structure.
	ServicedBySystems	SET [0:?] OF IfcRelServicesBuildings FOR RelatedBuildings	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.
	ReferencesElements	SET [0:?] OF IfcRelReferencedInSpatialStructure FOR RelatingStructure	Set of spatial reference relationships, that holds those elements, which are referenced, but not contained, within this element of the project spatial structure.
	IsInterferedByElements	SET [0:?] OF IfcRelInterferesElements FOR RelatedElement	Reference to the interference relationship to indicate the spatial element that is interfered. The relationship, if provided, indicates that this spatial element has an interference with one or many other spatial elements.
	InterferesElements	SET [0:?] OF IfcRelInterferesElements FOR RelatingElement	Reference to the interference relationship to indicate the spatial element that interferes. The relationship, if provided, indicates that this spatial element has an interference with one or many other spatial elements.
IfcSpatialStructureElement (1)
9	CompositionType	OPTIONAL IfcElementCompositionEnum	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 default value ''ELEMENT'' applies.
Click to show 28 hidden inherited attributes Click to hide 28 inherited attributes
IfcSite (5)
10	RefLatitude	OPTIONAL IfcCompoundPlaneAngleMeasure	World Latitude at reference point (most likely defined in legal description). Defined as integer values for degrees, minutes, seconds, and, optionally, millionths of seconds with respect to the world geodetic system WGS84.
11	RefLongitude	OPTIONAL IfcCompoundPlaneAngleMeasure	World Longitude at reference point (most likely defined in legal description). Defined as integer values for degrees, minutes, seconds, and, optionally, millionths of seconds with respect to the world geodetic system WGS84.
12	RefElevation	OPTIONAL IfcLengthMeasure	Datum elevation relative to sea level.
13	LandTitleNumber	OPTIONAL IfcLabel	The land title number (designation of the site within a regional system).
14	SiteAddress	OPTIONAL IfcPostalAddress	Address given to the site for postal purposes.

5.4.3.63.4 Property sets

• Pset_Address
  • Purpose
  • Description
  • UserDefinedPurpose
  • InternalLocation
  • AddressLines
  • PostalBox
  • Town
  • Region
  • PostalCode
  • Country
  • TelephoneNumbers
  • FacsimileNumbers
  • PagerNumber
  • ElectronicMailAddresses
  • WWWHomePageURL
  • MessagingIDs
• Pset_AirSideSystemInformation
  • Description
  • AirSideSystemType
  • AirSideSystemDistributionType
  • TotalAirFlow
  • EnergyGainTotal
  • AirFlowSensible
  • EnergyGainSensible
  • EnergyLoss
  • InfiltrationDiversitySummer
  • InfiltrationDiversityWinter
  • ApplianceDiversity
  • HeatingTemperatureDelta
  • CoolingTemperatureDelta
  • Ventilation
  • FanPower
• Pset_LandRegistration
  • LandID
  • IsPermanentID
  • LandTitleID
• Pset_PropertyAgreement
  • AgreementType
  • TrackingIdentifier
  • AgreementVersion
  • AgreementDate
  • PropertyName
  • CommencementDate
  • TerminationDate
  • Duration
  • Options
  • ConditionCommencement
  • Restrictions
  • ConditionTermination
• Pset_Risk
  • RiskName
  • RiskType
  • NatureOfRisk
  • RiskAssessmentMethodology
  • UnmitigatedRiskLikelihood
  • UnmitigatedRiskConsequence
  • UnmitigatedRiskSignificance
  • MitigationPlanned
  • MitigatedRiskLikelihood
  • MitigatedRiskConsequence
  • MitigatedRiskSignificance
  • MitigationProposed
  • AssociatedProduct
  • AssociatedActivity
  • AssociatedLocation
• Pset_SiteCommon
  • Reference
  • BuildableArea
  • SiteCoverageRatio
  • FloorAreaRatio
  • BuildingHeightLimit
  • TotalArea
• Pset_SiteWeather
  • MaxAmbientTemp
  • MinAmbientTemp
• Pset_SpaceAirHandlingDimensioning
  • CoolingDesignAirFlow
  • HeatingDesignAirFlow
  • SensibleHeatGain
  • TotalHeatGain
  • TotalHeatLoss
  • CoolingDryBulb
  • CoolingRelativeHumidity
  • HeatingDryBulb
  • HeatingRelativeHumidity
  • VentilationDesignAirFlow
  • DesignAirFlow
  • CeilingRAPlenum
  • BoundaryAreaHeatLoss
• Pset_SpaceCommon
  • Reference
  • IsExternal
  • GrossPlannedArea
  • NetPlannedArea
  • PubliclyAccessible
  • HandicapAccessible
• Pset_SpaceCoveringRequirements
  • FloorCovering
  • FloorCoveringThickness
  • WallCovering
  • WallCoveringThickness
  • CeilingCovering
  • CeilingCoveringThickness
  • SkirtingBoard
  • SkirtingBoardHeight
  • Molding
  • MoldingHeight
  • ConcealedFlooring
  • ConcealedFlooringOffset
  • ConcealedCeiling
  • ConcealedCeilingOffset
• Pset_SpaceFireSafetyRequirements
  • FireRiskFactor
  • FlammableStorage
  • FireExit
  • SprinklerProtection
  • SprinklerProtectionAutomatic
  • AirPressurization
• Pset_SpaceHVACDesign
  • TemperatureSetPoint
  • TemperatureMax
  • TemperatureMin
  • TemperatureSummerMax
  • TemperatureSummerMin
  • TemperatureWinterMax
  • TemperatureWinterMin
  • HumiditySetPoint
  • HumidityMax
  • HumidityMin
  • HumiditySummer
  • HumidityWinter
  • DiscontinuedHeating
  • NaturalVentilation
  • NaturalVentilationRate
  • MechanicalVentilation
  • MechanicalVentilationRate
  • AirConditioning
  • AirConditioningCentral
  • AirHandlingName
• Pset_SpaceLightingDesign
  • ArtificialLighting
  • Illuminance
• Pset_SpaceOccupancyRequirements
  • OccupancyType
  • OccupancyNumber
  • OccupancyNumberPeak
  • OccupancyTimePerDay
  • AreaPerOccupant
  • MinimumHeadroom
  • IsOutlookDesirable
• Pset_SpaceThermalLoad
  • People
  • Lighting
  • EquipmentSensible
  • VentilationIndoorAir
  • VentilationOutdoorAir
  • RecirculatedAir
  • ExhaustAir
  • AirExchangeRate
  • DryBulbTemperature
  • RelativeHumidity
  • InfiltrationSensible
  • TotalSensibleLoad
  • TotalLatentLoad
  • TotalRadiantLoad
• Pset_SpaceThermalLoadPHistory
  • PeopleHistory
  • LightingHistory
  • EquipmentSensibleHistory
  • VentilationIndoorAirHistory
  • VentilationOutdoorAirHistory
  • RecirculatedAirHistory
  • ExhaustAirHistory
  • AirExchangeRateTimeHistory
  • DryBulbTemperatureHistory
  • RelativeHumidityHistory
  • InfiltrationSensibleHistory
  • TotalSensibleLoadHistory
  • TotalLatentLoadHistory
  • TotalRadiantLoadHistory
• Pset_SpaceThermalPHistory
  • CoolingAirFlowRate
  • HeatingAirFlowRate
  • VentilationAirFlowRateHistory
  • ExhaustAirFlowRate
  • SpaceTemperatureHistory
  • SpaceRelativeHumidity
• Pset_ThermalLoad
  • OccupancyDiversity
  • LightingDiversity
  • ApplianceDiversity
  • OutsideAirPerPerson
  • ReceptacleLoadIntensity
  • AppliancePercentLoadToRadiant
  • LightingLoadIntensity
  • LightingPercentLoadToReturnAir
  • TotalCoolingLoad
  • TotalHeatingLoad
  • InfiltrationDiversitySummer
  • InfiltrationDiversityWinter
  • LoadSafetyFactor
• Pset_Tolerance
  • ToleranceDescription
  • ToleranceBasis
  • OverallTolerance
  • HorizontalTolerance
  • OrthogonalTolerance
  • VerticalTolerance
  • PlanarFlatness
  • HorizontalFlatness
  • ElevationalFlatness
  • SideFlatness
  • OverallOrthogonality
  • HorizontalOrthogonality
  • OrthogonalOrthogonality
  • VerticalOrthogonality
  • OverallStraightness
  • HorizontalStraightness
  • OrthogonalStraightness
  • VerticalStraightness
• Pset_Uncertainty
  • UncertaintyBasis
  • UncertaintyDescription
  • HorizontalUncertainty
  • LinearUncertainty
  • OrthogonalUncertainty
  • VerticalUncertainty
• Qto_BodyGeometryValidation
  • GrossSurfaceArea
  • NetSurfaceArea
  • GrossVolume
  • NetVolume
  • SurfaceGenusBeforeFeatures
  • SurfaceGenusAfterFeatures
• Qto_SiteBaseQuantities
  • GrossPerimeter
  • GrossArea

5.4.3.63.5 Concept usage

Concept	Usage	Description
IfcRoot (2)
Revision Control	General	Ownership, history, and merge state is captured using IfcOwnerHistory.
Software Identity	General	IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.
IfcObjectDefinition (9)
Classification Association	General	Any object occurrence or object type can have a reference to a specific classification reference, i.e. to a particular facet within a classification system.
Aggregation	General	No description available.
Approval Association	General	No description available.
Constraint Association	General	No description available.
Document Association	General	No description available.
Library Association	General	No description available.
Material Association	General	No description available.
Material Single	General	No description available.
Nesting	General	No description available.
IfcObject (5)
Object Predefined Type	General	No description available.
Object Typing	General	Any object occurrence can be typed by being assigned to a common object type utilizing this concept. A particular rule, restricting the applicable subtypes of IfcTypeObject that can be assigned, is introduced by overriding this concept at the level of subtypes of IfcObject. This concept can be applied to the following resources: IfcTypeObject
Object User Identity	General	An attribute Name and optionally Description can be used for all subypes of IfcObject. For those subtypes, that have an object type definition, such as IfcBeam - IfcBeamType, the common Name and optionally Description is associated with the object type.
Property Sets with Override	General	Any object occurrence can hold property sets, either directly at the object occurrence as element specific property sets, or at the object type, as type property sets. In this case, the properties that are provided to the object occurrence are the combinations of element specific and type properties. In case that the same property (within the same property set) is defined both in occurrence and type properties, the property value of the occurrence property overrides the property value of the type property.
Assignment to Group	General	No description available.
IfcProduct (18)
Body Geometry	General	The body or solid model geometric representation of an IfcProduct is typically defined using a Tessellation or Brep. Subtypes may provide recommendations on other representation types that may be used. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used: IfcShapeRepresentation.RepresentationIdentifier = 'Body' IfcShapeRepresentation.RepresentationType = Typically 'Tessellation' or 'Brep'
Product Geometric Representation	General	The geometric representation of any IfcProduct is provided by the IfcProductDefinitionShape allowing multiple geometric representations. It uses the Product Placement concept utilizing IfcLocalPlacement to establish an object coordinate system, in which all geometric representations are founded.
Product Geometry Colour	General	No description available.
Product Geometry Layer	General	No description available.
Product Relative Positioning	General	If the IfcProduct Product Placement is placed relative to an IfcPositioningElement this relationship covers the information on which IfcPositioningElement positions the IfcProduct.
Product Span Positioning	General	No description available.
Box Geometry	General	No description available.
CoG Geometry	General	No description available.
Mapped Geometry	General	No description available.
Object Typing	General	This concept can be applied to the following resources: IfcTypeProduct
Product Local Placement	General	No description available.
Product Topology Representation	General	No description available.
Property Sets for Objects	General	This concept can be applied to the following resources: Pset_Risk Pset_Tolerance Pset_Uncertainty
Quantity Sets	General	This concept can be applied to the following resources: Qto_BodyGeometryValidation
Reference Geometry	General	No description available.
Reference SweptSolid Geometry	General	No description available.
Reference SweptSolid PolyCurve Geometry	General	No description available.
Reference Tessellation Geometry	General	No description available.
IfcSpatialElement (11)
Body Geometry	General	A spatial element will not usually provide a body geometry, instead relying on its constituting elements. A body geometry may be provided if it is necessary to expose an independent geometric representation. This geometry is typically expressed by its exterior elements or volume boundary.
FootPrint GeomSet Geometry	General	No description available.
Group Spatial Connectivity	General	No description available.
Property Sets for Objects	General	This concept can be applied to the following resources: Pset_AirSideSystemInformation Pset_SpaceFireSafetyRequirements Pset_SpaceAirHandlingDimensioning Pset_SpaceThermalLoad Pset_SpaceCoveringRequirements Pset_SpaceHVACDesign Pset_SpaceLightingDesign Pset_SpaceOccupancyRequirements Pset_SpaceCommon Pset_ThermalLoad
Spatial Interference	General	No description available.
Spatial Interference With Zones	General	No description available.
Object Typing	General	This concept can be applied to the following resources: IfcSpatialElementType
Property Sets for Performance	General	This concept can be applied to the following resources: Pset_SpaceThermalLoadPHistory Pset_SpaceThermalPHistory
Spatial Container	General	This concept can be applied to the following resources: IfcAnnotation IfcElement IfcGrid
Spatial Element Attributes	General	No description available.
Spatial Service Connectivity	General	No description available.
IfcSpatialStructureElement (2)
Property Sets for Objects	General	This concept can be applied to the following resources: Pset_PropertyAgreement
Object Typing	General	This concept can be applied to the following resources: IfcSpatialStructureElementType
Click to show 47 hidden inherited concepts Click to hide 47 inherited concepts
IfcSite (9)
Body Geometry	General	The body representation of IfcSite may be typically defined using a solid or surface model. Applicable solids are Breps and Tessellations. Applicable surface models are the IfcFaceBasedSurfaceModel and the IfcShellBasedSurfaceModel. The representation identifier and type of this representation of IfcSite is: IfcShapeRepresentation.RepresentationIdentifier = 'Body' IfcShapeRepresentation.RepresentationType = 'Brep', or 'SurfaceModel'
FootPrint GeomSet Geometry	General	The foot print representation of IfcSite 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).
Product Local Placement	General	The local placement for IfcSite 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 to the IfcSpatialStructureElement of type "IfcSite", if relative placement is used (e.g. to position a site relative a a site complex, or a site section to a site). If the relative placement is not used, the absolute placement is defined within the world coordinate system. If there is only one site object, then this is the default situation.
Property Sets for Objects	General	This concept can be applied to the following resources: Pset_Address Pset_LandRegistration Pset_SiteCommon Pset_SiteWeather
Quantity Sets	General	This concept can be applied to the following resources: Qto_SiteBaseQuantities
Site Attributes	General	No description available.
Spatial Composition	General	By using the inverse relationship IfcSite.Decomposes it references IfcProject || IfcSite through IfcRelAggregates.RelatingObject, If it refers to another instance of IfcSite, the referenced IfcSite needs to have a different and higher CompositionType, i.e. COMPLEX (if the other IfcSite has ELEMENT), or ELEMENT (if the other IfcSite has PARTIAL). This concept can be applied to the following resources: IfcProject IfcSite
Spatial Container	General	If there are building elements and/or other elements directly related to the IfcSite (like a fence, or a shear wall), they are associated with the IfcSite by using the objectified relationship IfcRelContainedInSpatialStructure. The IfcSite references them by its inverse relationship: IfcSite.ContainsElements -- referencing any subtype of IfcProduct (with the exception of other spatial structure element) by IfcRelContainedInSpatialStructure.RelatedElements
Spatial Decomposition	General	By using the inverse relationship IfcSite.IsDecomposedBy it references (IfcSite || IfcBuilding || IfcSpace by IfcRelAggregates.RelatedObjects). If it refers to another instance of IfcSite, the referenced IfcSite needs to have a different and lower CompositionType, i.e. ELEMENT (if the other IfcSite has COMPLEX), or PARTIAL (if the other IfcSite has ELEMENT). This concept can be applied to the following resources: IfcSite IfcBuilding IfcFacility IfcBridge IfcMarineFacility IfcRailway IfcRoad IfcExternalSpatialElement IfcSpace

5.4.3.63.6 Examples

• 

  Beam Parametric Cross Section

• 

  Linear Placement Of Signal

• 

  Geographic Referencing Utm

• 

  Grid Placement

• 

  Column Straight Rectangle Tessellation

• 

  Fixed Reference Swept Area Solid

• 

  Sectioned Solid Horizontal

• 

  Geographic Referencing Rigid Operation

• 

  Construction Scheduling Task

• 

  Geographic Referencing Gk

5.4.3.63.7 Formal representation

ENTITY IfcSite
 SUBTYPE OF (IfcSpatialStructureElement);
	RefLatitude : OPTIONAL IfcCompoundPlaneAngleMeasure;
	RefLongitude : OPTIONAL IfcCompoundPlaneAngleMeasure;
	RefElevation : OPTIONAL IfcLengthMeasure;
	LandTitleNumber : OPTIONAL IfcLabel;
	SiteAddress : OPTIONAL IfcPostalAddress;
END_ENTITY;

5.4.3.63.8 References

• IfcSpatialStructureElement