IFC Migration Guide  

• IfcUtilityResource
• IfcMeasureResource
• IfcGeometryResource
• IfcPropertyTypeResource
• IfcPropertyResource

• IfcKernel
• IfcProductExtension
• IfcProcessExtension
• IfcDocumentExtension
• IfcModelingAidExtension

• IfcSharedBldgElements
• IfcSharedBldgServiceElements

• IfcArchitecture
• IfcFacilitiesMgmt
• IfcHvac

IfcUtilityResource

Simple Types

• IfcGloballyUniqueId (Change)
• IfcProjectUniqueId (Deleted)

Class Definitions

• IfcTable (Change)

IfcMeasureResource

Simple Types

• No changes

Select Types

• IfcMeasureValue (Change)

Enumerations

• No changes

Class Definitions

• No changes

IfcGeometryResource

Simple Types

• No changes

Select Types

• IfcBooleanOperand (New)
• IfcCsgSelect (New)

Enumerations

• IfcBooleanOperator (Change)

Class Definitions

• IfcArbitraryProfileDef (Change)
• IfcAttDrivenClippedExtrudedSolid (Change)
• IfcAttDrivenClippedRevolvedSolid (Change)
• IfcBooleanResult (New)
• IfcBoundedCurve (Change)
• IfcBoundingBox (Change)
• IfcBoxedHalfSpace (New)
• IfcCsgSolid (New)
• IfcPlacement (Change)
• IfcAttDrivenProfileDef (Change)
• IfcAxis1Placement (Change)
• IfcAxis2Placement2D (Change)
• IfcAxis2Placement3D (Change)
• IfcCompositeCurve (Change)
• IfcPolyline (Change)
• IfcTrimmedCurve (Change)
• IfcAttDrivenMorphedExtrudedSegment (Change)

IfcPropertyTypeResource

Enumerations

• IfcShapeRepTypeEnum (Change)

Class Definitions

• IfcObjectReference (Change)
• IfcProductShape (Change)
• IfcPropertySet (Change)
• IfcPropertyTypeDef (Change)
• IfcRepresentationContext (Change)
• IfcShapeAspect (New)
• IfcShapeRepresentation (Change)
• IfcShapeBody (Deleted)
• IfcShapeResult (Deleted)

IfcPropertyResource

Simple Types

• No changes

Select Types

• IfcMaterialSelect (Change)

Enumerations

• No changes

Class Definitions

• IfcClassificationNotation (Change)
• IfcMaterial (Change)
• IfcMaterialComposite (Change)
• IfcMaterialLayer (Change)
• IfcMaterialLayerSetUsage (Change)
• IfcNotationFacet (Change)

IfcKernel

Select Types

• No changes

Enumerations

• IfcContainmentTypeEnum (Change)
• IfcResourceTypeEnum (New)

Class Definitions

• IfcObject (Change)
• IfcProcess (Change)
• IfcProduct (Change)
• IfcProject (Change)
• IfcRelContains (Change)
• IfcRelGroups (Change)
• IfcRelNests (New)
• IfcRelProcessesProducts (New)
• IfcRelSequence (Change)
• IfcRelUsesResource (New)
• IfcResource (Change)
• IfcRoot (Change)
• IfcRelUsesProducts (Deleted)
• IfcRelationship1to1 (Deleted)
• IfcRelationship1toN (Deleted)

IfcProductExtension

Enumerations

• IfcConnectionTypeEnum (Change)
• IfcSystemTypeEnum (Change)
• IfcElementFunctionTypeEnum (Deleted)

Class Definitions

• IfcBuildingElement (Change)
• IfcLineConnectionGeometry (New)
• IfcOpeningElement (Change)
• IfcRelAssemblesElements (Change)
• IfcRelAssemblesSpaces (Change)
• IfcRelConnectsElements (Change)
• IfcRelFillsElement (New)
• IfcRelSeparatesSpaces (Change)
• IfcRelServicesBuildings (Change)
• IfcRelVoidsElement (New)
• IfcSpaceBoundary (Change)
• IfcSystem (Change)
• IfcBuilding (Change)
• IfcBuildingStorey (Change)
• IfcElement (Change)
• IfcRelFillsElements (Deleted)
• IfcRelVoidsElements (Deleted)
• IfcSite (Change)
• IfcSpace (Change)

IfcProcessExtension

Enumerations

• No changes

Class Definitions

• IfcRelNestsProcesses (New)
• IfcWorkTask (Change)
• IfcRelResourceUse (Deleted)
• IfcWorkGroup (Deleted)
• IfcWorkSchedule (Change)

IfcDocumentExtension

Class Definitions

• IfcCostElement (Change)
• IfcCostSchedule (Change)
• IfcRelCostsProducts (New)
• IfcRelNestsCostElements (New)
• IfcCostElementGroup (Deleted)
• IfcRelCostScheduleElement (Deleted)

IfcModelingAidExtension

Select Types

• No changes

Class Definitions

• No changes

IfcSharedBldgElements

Enumerations

• No changes

Class Definitions

• IfcBeam (Change)
• IfcColumn (Change)
• IfcCovering (Change)
• IfcFloor (Change)
• IfcRelCoversBldgElements (Change)
• IfcRoofSlab (Change)
• IfcWall (Change)

IfcSharedBldgServiceElements

Enumerations

• No changes

Class Definitions

• No changes

IfcArchitecture

Enumerations

• No changes

Class Definitions

• IfcRelAdjacencyReq (Change)

IfcFacilitiesMgmt

Enumerations

• No changes

Class Definitions

• No changes

IfcHvac

Type IfcGloballyUniqueId

Type

Release 1.5.1	Change from Release 1.5 Final
STRING(20)FIXED	STRING

Class IfcTable

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ProjectId	IfcGloballyUniqueId	IfcProjectUniqueId
Name	String	No Change
Rows	LIST [1:?] OF IfcTableRow	No Change
NumberOfCellsInRow	Integer	New attribute in Release 1.5.1
NumberOfHeadings	Integer	No Change
NumberOfDataRows	Integer	No Change
NumberOfCellsinRow	Integer	Deleted

Type IfcMeasureValue

Select

Release 1.5.1	Change from Release 1.5 Final
IfcLengthMeasure	No Change
IfcMassMeasure	No Change
IfcTimeMeasure	No Change
IfcElectricCurrentMeasure	No Change
IfcThermodynamicTemperatureMeasure	No Change
IfcAmountOfSubstanceMeasure	No Change
IfcLuminousIntensityMeasure	No Change
IfcPlaneAngleMeasure	No Change
IfcSolidAngleMeasure	No Change
IfcAreaMeasure	No Change
IfcVolumeMeasure	No Change
IfcRatioMeasure	No Change
IfcParameterValue	No Change
IfcNumericMeasure	No Change
IfcContextDependentMeasure	No Change
IfcDescriptiveMeasure	No Change
IfcPositiveLengthMeasure	No Change
IfcPositivePlaneAngleMeasure	No Change
IfcPositiveRatioMeasure	No Change
IfcCountMeasure	No Change
IfcCompoundPlaneAngleMeasure	No Change
IfcTimeDurationMeasure	No Change
IfcTimeStamp	No Change
IfcBoolean	New in Release 1.5.1
IfcInteger	New in Release 1.5.1
IfcReal	New in Release 1.5.1
IfcString	New in Release 1.5.1

Type IfcBooleanOperand

New type in Release 1.5.1

Type IfcCsgSelect

New type in Release 1.5.1

Type IfcBooleanOperator

Schema

Moved from IfcPropertyTypeResource to IfcGeometryResource in Release 1.5.1

Enumeration

Release 1.5.1	Change from Release 1.5 Final
Union	No Change
Intersection	No Change
Difference	No Change

Class IfcArbitraryProfileDef

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
CurveForSurface	IfcBoundedCurve	No Change
Position	IfcAxis2Placement2D	New attribute in Release 1.5.1

Class IfcAttDrivenClippedExtrudedSolid

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ClippingHalfSpaces	LIST [1:?] OF IfcHalfSpaceSolid	LIST [1:2] OF IfcHalfSpaceSolid

Class IfcAttDrivenClippedRevolvedSolid

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ClippingHalfSpaces	LIST [1:?] OF IfcHalfSpaceSolid	LIST [1:2] OF IfcHalfSpaceSolid

Class IfcAttDrivenMorphedExtrudedSegment

Change description

Within WR2 SELF\IfcAttDrivenRevolvedSegment is replaced by SELF\IfcAttDrivenExtrudedSegment

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
EndProfileDef	IfcAttDrivenProfileDef	No Change
EndSweptArea	IfcCurveBoundedPlane	No Change

Class IfcAttDrivenProfileDef

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Position	IfcAxis2Placement2D	No Change
ProfileType	IfcProfileTypeEnum	No Change
PositionToOrigin	LIST [2:2] OF IfcLengthMeasure	Deleted
AngleInOrigin	IfcPlaneAngleMeasure	Deleted

Class IfcAxis1Placement

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Axis	OPTIONAL IfcDirection	No Change
Z	IfcDirection	No Change
Dim	IfcDimensionCount	Deleted

Class IfcAxis2Placement2D

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RefDirection	OPTIONAL IfcDirection	No Change
P	LIST [2:2] OF IfcDirection	No Change
Dim	IfcDimensionCount	Deleted

Class IfcAxis2Placement3D

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Axis	OPTIONAL IfcDirection	No Change
RefDirection	OPTIONAL IfcDirection	No Change
P	LIST [3:3] OF IfcDirection	No Change
Dim	IfcDimensionCount	Deleted

Class IfcBooleanResult

New entity in Release 1.5.1

Class IfcBoundedCurve

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Dim	IfcDimensionCount	New attribute in Release 1.5.1

Class IfcBoundingBox

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Corner	IfcCartesianPoint	New attribute in Release 1.5.1
XDim	IfcPositiveLengthMeasure	No Change
YDim	IfcPositiveLengthMeasure	No Change
ZDim	IfcPositiveLengthMeasure	No Change
Dim	IfcDimensionCount	No Change
Position	IfcAxis2Placement3D	Deleted

Class IfcBoxedHalfSpace

New entity in Release 1.5.1

Class IfcCompositeCurve

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Segments	LIST [1:?] OF IfcCompositeCurveSegment	No Change
SelfIntersect	Logical	No Change
NSegments	Integer	No Change
ClosedCurve	Logical	No Change
Dim	IfcDimensionCount	Deleted

Class IfcCsgSolid

New entity in Release 1.5.1

Change description

Add this entity for basic CSG tree, based on Part 42

Class IfcPlacement

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Location	IfcCartesianPoint	No Change
Dim	IfcDimensionCount	New attribute in Release 1.5.1

Class IfcPolyline

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Points	LIST [2:?] OF IfcCartesianPoint	No Change
Dim	IfcDimensionCount	Deleted

Class IfcTrimmedCurve

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
BasisCurve	IfcCurve	No Change
Trim1	SET [1:2] OF IfcTrimmingSelect	No Change
Trim2	SET [1:2] OF IfcTrimmingSelect	No Change
SenseAgreement	Boolean	No Change
MasterRepresentation	IfcTrimmingPreference	No Change
Dim	IfcDimensionCount	Deleted

Type IfcShapeRepTypeEnum

Enumeration

Release 1.5.1	Change from Release 1.5 Final
BoundingBox	No Change
Standard	New in Release 1.5.1
Advanced	New in Release 1.5.1
Arbitrary	New in Release 1.5.1
AttributeDriven	Deleted
Explicit	Deleted

Class IfcObjectReference

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Descriptor	String	No Change
ObjectReference	IfcGloballyUniqueId	IfcProjectUniqueId

Class IfcProductShape

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ProjectId	IfcGloballyUniqueId	IfcProjectUniqueId
ShapeRepresentations	LIST [1:?] OF IfcShapeRepresentation	New attribute in Release 1.5.1
Descriptor	OPTIONAL String	No Change
HasShapeAspects	SET [0:?] OF IfcShapeAspect	New attribute in Release 1.5.1
ProductComponentShape	IfcProductComponentShapeSelect	Deleted

Class IfcPropertySet

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ProjectId	IfcGloballyUniqueId	IfcProjectUniqueId
Descriptor	String	No Change
HasProperties	LIST [1:?] OF IfcProperty	No Change

Class IfcPropertyTypeDef

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ProjectId	IfcGloballyUniqueId	IfcProjectUniqueId
OwnerHistory	IfcOwnerHistory	No Change
TypeDefName	String	No Change
TypedClass	String	No Change
GenericType	OPTIONAL String	No Change
SpecificType	OPTIONAL String	No Change
TypeDomainView	IfcTypeDefDomainViewEnum	No Change
SharedProperties	LIST [0:?] OF IfcSharedPropertySet	No Change
GenericTypeReference	OPTIONAL IfcPropertyTypeDef	No Change
ReferencedBySpecificType	SET [0:?] OF IfcPropertyTypeDef	No Change
OccurrenceSets	SET [0:?] OF IfcOccurrencePropertySet	No Change

Class IfcRepresentationContext

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ProjectId	IfcGloballyUniqueId	IfcProjectUniqueId
DetailType	IfcRepDetailTypeEnum	No Change
ViewType	IfcRepViewTypeEnum	No Change
Precision	Integer	No Change
RepresentationsInContext	SET [1:?] OF IfcShapeRepresentation	No Change

Class IfcShapeAspect

New entity in Release 1.5.1

Class IfcShapeRepresentation

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Items	SET [1:?] OF IfcGeometricRepresentationItem	No Change
ContextOfItems	IfcRepresentationContext	No Change
RepresentationType	IfcShapeRepTypeEnum	No Change
UsageDescriptor	OPTIONAL String	No Change
OfProductShape	SET [0:1] OF IfcProductShape	New attribute in Release 1.5.1
OfShapeAspect	SET [0:1] OF IfcShapeAspect	New attribute in Release 1.5.1
OfShapeBody	IfcShapeBody	Deleted

Type IfcMaterialSelect

Select

Release 1.5.1	Change from Release 1.5 Final
IfcMaterial	New in Release 1.5.1
IfcMaterialLayerSet	No Change
IfcMaterialComposite	New in Release 1.5.1
IfcMaterialList	Deleted

Class IfcClassificationNotation

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
NotationFacets	LIST [1:?] OF IfcNotationFacet	New attribute in Release 1.5.1
NotationStrings	LIST [1:?] OF IfcNotationString	Deleted

Class IfcMaterial

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
MaterialName	String	No Change
MaterialClassification	OPTIONAL IfcClassificationList	IfcClassificationList
RegisteredBy	IfcProjectMaterialRegistry	No Change

Class IfcMaterialComposite

Name

Name changed from IfcMaterialList to IfcMaterialComposite in Release 1.5.1

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Materials	LIST [1:?] OF IfcMaterial	IfcMaterial

Class IfcMaterialLayer

Superclass

Superclass changed from Nothing to IfcProperty

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
Material	IfcMaterial	No Change
OffsetFromMLSBase	IfcPositiveLengthMeasure	No Change
LayerThickness	IfcPositiveLengthMeasure	No Change
DefaultPriority	Integer	No Change

Class IfcMaterialLayerSetUsage

Superclass

Superclass changed from Nothing to IfcProperty

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ForLayerSet	IfcMaterialLayerSet	No Change
MlsOffsetFromBaseline	IfcLengthMeasure	No Change
MlsSenseLtoR	Boolean	No Change
TotalThickness	IfcLengthMeasure	No Change

Class IfcNotationFacet

Name

Name changed from IfcNotationString to IfcNotationFacet in Release 1.5.1

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
NotationValue	String	No Change
Purpose	OPTIONAL String	No Change
Separator	String	Deleted

Type IfcContainmentTypeEnum

Schema

Moved from IfcProductExtension to IfcKernel in Release 1.5.1

Enumeration

Release 1.5.1	Change from Release 1.5 Final
ProjectContainer	No Change
SiteContainer	No Change
BuildingContainer	No Change
BuildingStoreyContainer	No Change
SpaceContainer	No Change

Type IfcResourceTypeEnum

New type in Release 1.5.1

Class IfcObject

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
OwnerHistory	IfcOwnerHistory	No Change
TypeDefinitions	LIST [0:?] OF IfcPropertyTypeDef	No Change
OccurrenceProperties	LIST [0:?] OF IfcOccurrencePropertySet	No Change
ExtendedProperties	LIST [0:?] OF IfcPropertySet	No Change
PartOfGroups	SET [0:?] OF IfcRelGroups	No Change
Nests	SET [0:1] OF IfcRelNests	New attribute in Release 1.5.1
IsNestedBy	SET [0:?] OF IfcRelNests	New attribute in Release 1.5.1
Contains	SET [0:2] OF IfcRelContains	New attribute in Release 1.5.1
IsContainedBy	SET [0:?] OF IfcRelContains	New attribute in Release 1.5.1

Class IfcProcess

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
PerformedBy	SET [0:?] OF IfcActorSelect	No Change
Classification	OPTIONAL IfcClassificationList	No Change
IsSuccessorFrom	SET [0:?] OF IfcRelSequence	No Change
IsPredecessorTo	SET [0:?] OF IfcRelSequence	No Change
ProcessesProducts	SET [0:2] OF IfcRelProcessesProducts	New attribute in Release 1.5.1
UsesResources	SET [0:?] OF IfcRelUsesResource	New attribute in Release 1.5.1
UsesProducts	SET [0:2] OF IfcRelUsesProducts	Deleted

Class IfcProduct

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
LocalPlacement	IfcLocalPlacement	No Change
ProductShape	OPTIONAL IfcProductShape	No Change
ProductCost	OPTIONAL IfcCost	No Change
Classification	OPTIONAL IfcClassificationList	No Change
PrcessedInProcesses	SET [0:?] OF IfcRelProcessesProducts	New attribute in Release 1.5.1
UsedInProcesses	SET [0:?] OF IfcRelUsesProducts	Deleted

Class IfcProject

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
UnitsInContext	IfcUnitAssignment	No Change
ProjectTeam	IfcProjectTeamRegistry	No Change
ProjectApps	IfcProjectAppRegistry	No Change
Classification	OPTIONAL IfcClassificationList	No Change
AbsolutePlacement	IfcAxis2Placement	No Change
ProjectMaterials	IfcProjectMaterialRegistry	New attribute in Release 1.5.1
GlobalId	IfcGloballyUniqueId	Deleted

Class IfcRelContains

Schema

Moved from IfcProductExtension to IfcKernel in Release 1.5.1

Superclass

Superclass changed from IfcRelationship1toN to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingObject	IfcObject	New attribute in Release 1.5.1
RelatedObjects	LIST [1:?] OF IfcObject	New attribute in Release 1.5.1
RelationshipType	IfcContainmentTypeEnum	No Change
ContainedOrReferenced	Boolean	No Change

Class IfcRelGroups

Superclass

Superclass changed from IfcRelationship1toN to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingGroup	IfcGroup	New attribute in Release 1.5.1
RelatedObjects	LIST [1:?] OF IfcObject	No Change
RelatingObject	IfcGroup	Deleted

Class IfcRelNests

New entity in Release 1.5.1

Class IfcRelProcessesProducts

New entity in Release 1.5.1

Class IfcRelSequence

Superclass

Superclass changed from IfcRelationship1to1 to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingProcess	IfcProcess	New attribute in Release 1.5.1
RelatedProcess	IfcProcess	New attribute in Release 1.5.1
TimeLag	IfcTimeDurationMeasure	No Change
SequenceType	IfcSequenceTypeEnum	No Change
RelatingObject	IfcProcess	Deleted
RelatedObject	IfcProcess	Deleted

Class IfcRelUsesResource

New entity in Release 1.5.1

Class IfcResource

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcResourceTypeEnum	New attribute in Release 1.5.1
Descriptor	OPTIONAL String	New attribute in Release 1.5.1
UnitCost	OPTIONAL IfcCost	New attribute in Release 1.5.1
UsedInProcesses	SET [0:?] OF IfcRelUsesResource	New attribute in Release 1.5.1

Class IfcRoot

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ProjectId	IfcGloballyUniqueId	IfcProjectUniqueId

Type IfcConnectionTypeEnum

Enumeration

Release 1.5.1	Change from Release 1.5 Final
AtPath	No Change
Start	No Change
AtEnd	No Change
NotKnown	New in Release 1.5.1

Type IfcSystemTypeEnum

Enumeration

Release 1.5.1	Change from Release 1.5 Final
ElectricalSystem	New in Release 1.5.1
HvacSystem	New in Release 1.5.1
LightingSystem	New in Release 1.5.1
PlumbingSystem	New in Release 1.5.1
StructuralSystem	No Change
EnclosingSystem	Deleted
DistributionSystem	Deleted
FurnishingSystem	Deleted
SpatialSystem	Deleted

Class IfcBuilding

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcBuildingTypeEnum	No Change
calcTotalHeight	OPTIONAL IfcLengthMeasure	No Change
calcSiteCoverage	OPTIONAL IfcAreaMeasure	No Change
calcTotalVolume	OPTIONAL IfcVolumeMeasure	No Change
ServicedBySystems	SET [0:?] OF IfcRelServicesBuildings	No Change
Contains	SET [0:?] OF IfcRelContains	Deleted
IsContainedBy	SET [0:?] OF IfcRelContains	Deleted

Class IfcBuildingElement

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
HasMaterial	OPTIONAL IfcMaterialSelect	No Change
ProvidesBoundaries	SET [0:?] OF IfcRelSeparatesSpaces	No Change
HasOpenings	SET [0:?] OF IfcRelVoidsElement	New attribute in Release 1.5.1
FillsVoids	SET [0:?] OF IfcRelFillsElement	New attribute in Release 1.5.1

Class IfcBuildingStorey

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcBuildingStoreyTypeEnum	No Change
Elevation	IfcLengthMeasure	No Change
calcTotalHeight	OPTIONAL IfcLengthMeasure	No Change
calcTotalArea	OPTIONAL IfcAreaMeasure	No Change
calcTotalVolume	OPTIONAL IfcVolumeMeasure	No Change
Contains	SET [0:?] OF IfcRelContains	Deleted
IsContainedBy	SET [0:?] OF IfcRelContains	Deleted

Class IfcElement

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ConnectedTo	SET [0:?] OF IfcRelConnectsElements	No Change
ConnectedFrom	SET [0:?] OF IfcRelConnectsElements	No Change
IsAssemblyThrough	SET [0:1] OF IfcRelAssemblesElements	No Change
PartOfAssembly	SET [0:1] OF IfcRelAssemblesElements	No Change
PerformedFunctions	SET [0:?] OF IfcElementFunctionTypeEnum	Deleted
HasOpenings	SET [0:?] OF IfcRelVoidsElements	Deleted
FillsVoids	SET [0:1] OF IfcRelFillsElements	Deleted
IsContainedBy	SET [0:?] OF IfcRelContains	Deleted

Class IfcLineConnectionGeometry

New entity in Release 1.5.1

Class IfcOpeningElement

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcOpeningTypeEnum	No Change
calcOpeningArea	OPTIONAL IfcAreaMeasure	New attribute in Release 1.5.1
VoidsElements	SET [0:1] OF IfcRelVoidsElement	SET [0:1] OF IfcRelVoidsElements
HasFillings	SET [0:?] OF IfcRelFillsElement	SET [0:?] OF IfcRelFillsElements

Class IfcRelAssemblesElements

Superclass

Superclass changed from IfcRelationship1toN to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingElement	IfcElement	New attribute in Release 1.5.1
RelatedElements	LIST [1:?] OF IfcElement	New attribute in Release 1.5.1
RelatingObject	IfcElement	Deleted
RelatedObjects	LIST [1:?] OF IfcElement	Deleted

Class IfcRelAssemblesSpaces

Superclass

Superclass changed from IfcRelationship1toN to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingSpace	IfcSpace	New attribute in Release 1.5.1
RelatedSpaces	LIST [1:?] OF IfcSpace	New attribute in Release 1.5.1
RelatingObject	IfcSpace	Deleted
RelatedObjects	LIST [1:?] OF IfcSpace	Deleted

Class IfcRelConnectsElements

Superclass

Superclass changed from IfcRelationship1to1 to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ConnectionGeometry	OPTIONAL IfcConnectionGeometry	IfcConnectionGeometry
RelatingElement	IfcElement	New attribute in Release 1.5.1
RelatedElement	IfcElement	New attribute in Release 1.5.1
RelatingObject	IfcElement	Deleted
RelatedObject	IfcElement	Deleted

Class IfcRelFillsElement

New entity in Release 1.5.1

Class IfcRelSeparatesSpaces

Superclass

Superclass changed from IfcRelationship1toN to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingBuildingElement	IfcBuildingElement	New attribute in Release 1.5.1
RelatedSpaceBoundaries	LIST [1:?] OF IfcSpaceBoundary	New attribute in Release 1.5.1
RelatingObject	IfcBuildingElement	Deleted
RelatedObjects	LIST [1:?] OF IfcSpaceBoundary	Deleted

Class IfcRelServicesBuildings

Superclass

Superclass changed from IfcRelationship1toN to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingSystem	IfcSystem	New attribute in Release 1.5.1
RelatedBuildings	LIST [1:?] OF IfcBuilding	New attribute in Release 1.5.1
RelatingObject	IfcSystem	Deleted
RelatedObjects	LIST [1:?] OF IfcBuilding	Deleted

Class IfcRelVoidsElement

New entity in Release 1.5.1

Class IfcSite

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcSiteTypeEnum	No Change
RefLatitude	IfcCompoundPlaneAngleMeasure	No Change
RefLongitude	IfcCompoundPlaneAngleMeasure	No Change
RefElevation	IfcLengthMeasure	No Change
calcSitePerimeter	OPTIONAL IfcPositiveLengthMeasure	No Change
calcSiteArea	OPTIONAL IfcAreaMeasure	No Change
Contains	SET [0:?] OF IfcRelContains	Deleted
IsContainedBy	SET [0:?] OF IfcRelContains	Deleted

Class IfcSpace

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcSpaceTypeEnum	No Change
BoundedBy	LIST [1:?] OF IfcSpaceBoundary	No Change
calcTotalPerimeter	OPTIONAL IfcPositiveLengthMeasure	No Change
calcTotalArea	OPTIONAL IfcAreaMeasure	No Change
calcTotalVolume	OPTIONAL IfcVolumeMeasure	No Change
calcAverageHeight	OPTIONAL IfcPositiveLengthMeasure	No Change
IsAssemblyThrough	SET [0:1] OF IfcRelAssemblesSpaces	No Change
PartOfAssembly	SET [0:1] OF IfcRelAssemblesSpaces	No Change
Contains	SET [0:?] OF IfcRelContains	Deleted
IsContainedBy	SET [0:?] OF IfcRelContains	Deleted

Class IfcSpaceBoundary

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
PhysicalOrVirtual	Boolean	No Change
calcBoundarySurfaceArea	OPTIONAL IfcAreaMeasure	New attribute in Release 1.5.1
Bounds	SET [1:2] OF IfcSpace	No Change
ProvidedBy	SET [0:1] OF IfcRelSeparatesSpaces	No Change

Class IfcSystem

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcSystemTypeEnum	No Change
ServicesBuildings	SET [0:1] OF IfcRelServicesBuildings	IfcRelServicesBuildings

Class IfcRelNestsProcesses

New entity in Release 1.5.1

Class IfcWorkSchedule

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ActualStart	OPTIONAL IfcDateTimeSelect	No Change
EarliestStart	OPTIONAL IfcDateTimeSelect	No Change
LatestStart	OPTIONAL IfcDateTimeSelect	No Change
ActualFinish	OPTIONAL IfcDateTimeSelect	No Change
EarliestFinish	OPTIONAL IfcDateTimeSelect	No Change
LatestFinish	OPTIONAL IfcDateTimeSelect	No Change
StatusTime	OPTIONAL IfcDateTimeSelect	No Change
ScheduledStart	OPTIONAL IfcDateTimeSelect	No Change
ScheduledFinish	OPTIONAL IfcDateTimeSelect	No Change
ScheduledDuration	OPTIONAL IfcTimeDurationMeasure	No Change
RemainingTime	OPTIONAL IfcTimeDurationMeasure	No Change
FreeFloat	OPTIONAL IfcTimeDurationMeasure	No Change
TotalFloat	OPTIONAL IfcTimeDurationMeasure	No Change
TaskStatus	OPTIONAL IfcTaskStatusEnum	No Change
IsCritical	OPTIONAL Boolean	No Change
WorkSchedule	IfcWorkTaskOrGroupSelect	Deleted

Class IfcWorkTask

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
WorkTaskId	OPTIONAL String	No Change
TaskDescription	OPTIONAL String	No Change
TaskCost	OPTIONAL IfcCost	No Change
WorkMethod	OPTIONAL String	No Change
WorkTaskSchedulingData	OPTIONAL IfcWorkSchedule	New attribute in Release 1.5.1

Class IfcCostElement

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ContextDescription	OPTIONAL String	New attribute in Release 1.5.1
ElementCost	OPTIONAL IfcCost	No Change
ExtensionCost	OPTIONAL IfcCost	No Change
PreparedOn	OPTIONAL IfcDateTimeSelect	New attribute in Release 1.5.1
Quantity	OPTIONAL Number	New attribute in Release 1.5.1
PartOfCostSchedule	SET [0:1] OF IfcCostSchedule	New attribute in Release 1.5.1
CostsProducts	SET [0:1] OF IfcRelCostsProducts	New attribute in Release 1.5.1
Description	String	Deleted

Class IfcCostSchedule

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
ScheduleTitle	String	No Change
SubmittedBy	OPTIONAL IfcActorSelect	No Change
ApprovedBy	OPTIONAL IfcPerson	No Change
PreparedBy	OPTIONAL IfcPerson	No Change
SubmittedOn	OPTIONAL IfcDateTimeSelect	No Change
Cost	OPTIONAL IfcCost	No Change
HasCostElements	LIST [1:?] OF IfcCostElement	New attribute in Release 1.5.1
HasCostElementGroup	LIST [1:?] OF IfcCostElementGroup	Deleted

Class IfcRelCostsProducts

New entity in Release 1.5.1

Class IfcRelNestsCostElements

New entity in Release 1.5.1

Class IfcBeam

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcBeamTypeEnum	No Change
calcBeamSectionArea	OPTIONAL IfcAreaMeasure	New attribute in Release 1.5.1
calcBeamVolume	OPTIONAL IfcVolumeMeasure	New attribute in Release 1.5.1

Class IfcColumn

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcColumnTypeEnum	No Change
calcColumnSectionArea	OPTIONAL IfcAreaMeasure	New attribute in Release 1.5.1
calcColumnVolume	OPTIONAL IfcVolumeMeasure	New attribute in Release 1.5.1

Class IfcCovering

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcCoveringTypeEnum	No Change
LayerInformation	IfcMaterialLayerSetUsage	No Change
calcCoveringArea	OPTIONAL IfcAreaMeasure	New attribute in Release 1.5.1
HasMaterial	IfcMaterialSelect	No Change
Covers	IfcRelCoversBldgElements	No Change

Class IfcFloor

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcFloorTypeEnum	No Change
LayerInformation	IfcMaterialLayerSetUsage	No Change
calcFloorArea	OPTIONAL IfcAreaMeasure	New attribute in Release 1.5.1
calcFloorVolume	OPTIONAL IfcVolumeMeasure	New attribute in Release 1.5.1
HasMaterial	IfcMaterialSelect	No Change

Class IfcRelCoversBldgElements

Superclass

Superclass changed from IfcRelationship1toN to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingBuildingElement	IfcBuildingElement	New attribute in Release 1.5.1
RelatedCoverings	LIST [1:?] OF IfcCovering	New attribute in Release 1.5.1
RelatingObject	IfcBuildingElement	Deleted
RelatedObjects	LIST [1:?] OF IfcCovering	Deleted

Class IfcRoofSlab

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcRoofSlabTypeEnum	No Change
LayerInformation	IfcMaterialLayerSetUsage	No Change
calcRoofSlabArea	OPTIONAL IfcAreaMeasure	New attribute in Release 1.5.1
calcRoofSlabVolume	OPTIONAL IfcVolumeMeasure	New attribute in Release 1.5.1
HasMaterial	IfcMaterialSelect	No Change

Class IfcWall

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
GenericType	IfcWallTypeEnum	No Change
LayerInformation	IfcMaterialLayerSetUsage	No Change
calcWallArea	OPTIONAL IfcAreaMeasure	New attribute in Release 1.5.1
calcWallVolume	OPTIONAL IfcVolumeMeasure	New attribute in Release 1.5.1
HasMaterial	IfcMaterialSelect	No Change

Class IfcRelAdjacencyReq

Superclass

Superclass changed from IfcRelationship1to1 to IfcRelationship

Attributes and Relationships

Attribute / Relation	Release 1.5.1	Change from Release 1.5 Final
RelatingSpaceProgram	IfcSpaceProgram	New attribute in Release 1.5.1
RelatedSpaceProgram	IfcSpaceProgram	New attribute in Release 1.5.1
RequiredAdjacency	Integer	No Change
RelatingObject	IfcSpaceProgram	Deleted
RelatedObject	IfcSpaceProgram	Deleted

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