ARCHITECTURE LAYER

New

Schema

Changed

affects P21 file -->

Entity / Function

Deleted

not upward compatible

Attribute / WR

Usage

Change description

IfcGeometricConstraintResource

IfcPointOrVertexPoint

x

New select type to enable connection between geometry and topology

IfcCurveOrEdgeCurve

x

New select type to enable connection between geometry and topology

IfcSurfaceOrFaceSurface

x

New select type to enable connection between geometry and topology

IfcConnectionPointEccentricity

x

New entity to support eccentricity between structural items

x

EccentricityInX

x

New attribute

EccentricityInY

x

New attribute

EccentricityInZ

x

New attribute

IfcConnectionPointGeometry

x

PointOnRelatedElement

x

attribute type changed to IfcPointOrVertexPoint

PointOnRelatingElement

x

attribute type changed to IfcPointOrVertexPoint

IfcConnectionCurveGeometry

x

PointOnRelatedElement

x

attribute type changed to IfcCurveOrEdgeCurve

PointOnRelatingElement

x

attribute type changed to IfcCurveOrEdgeCurve

IfcConnectionSurfaceGeometry

x

PointOnRelatedElement

x

attribute type changed to IfcSurfaceOrFaceSurface

PointOnRelatingElement

x

attribute type changed to IfcSurfaceOrFaceSurface

IfcGridAxis

(INV)PartOfU

x

new inverse relationship to IfcGrid

(INV)PartOfV

x

new inverse relationship to IfcGrid

(INV)PartOfW

x

new inverse relationship to IfcGrid

(INV)HasIntersections

x

new inverse relationship to IfcVirtualGridIntersection

IfcObjectPlacement

(INV) PlacesObjects

x

new inverse relationship to IfcProduct

IfcGeometricModelResource

IfcBlock

x

new entity to describe CSG primitives

x

XLength

x

new attribute

YLength

x

new attribute

ZLength

x

new attribute

IfcBooleanOperand

x

select enhanced to include IfcCsgPrimitive3D

IfcCsgSelect

x

select enhanced to include IfcCsgPrimitive3D

IfcCsgPrimitive3D

x

new entity to describe CSG primitives

x

Position

x

new attribute

IfcPolygonalBoundedHalfSpace

PolygonalBoundary

x

attribute type changed to IfcBoundedCurve

x

IfcRectangularPyramid

x

new entity to describe CSG primitives

x

XLength

x

new attribute

YLength

x

new attribute

Height

x

new attribute

IfcRightCircularCylinder

x

new entity to describe CSG primitives

x

Height

x

new attribute

Radius

x

new attribute

IfcRightCircularCone

x

new entity to describe CSG primitives

x

Height

x

new attribute

BottomRadius

x

new attribute

IfcSphere

x

new entity to describe CSG primitives

x

Radius

x

new attribute

IfcSweptAreaSolid

WR1

x

rule deleted, derived profile can be used

IfcGeometryResource

IfcRepresentationItem

(INV) StyledByItem

x

Inverse attribute added to access the presentation from geometry

(INV) LayerAssignments

x

Inverse attribute added to access the layer from geometry

IfcVectorDifference

x

function corrected

IfcMaterialResource

IfcMaterial

(INV) HasRepresentation

x

Inverse attribute added to access the presentation from material

IfcMeasureResource

IfcUnitAssignment

WR01

x

WR added to prevent duplicated units definitions

IfcCorrectUnitAssignment

x

new function to secure non-duplicated unit assignments

IfcPresentationAppearanceResource

IfcBlobTexture

x

New entity to have a pixel file included as a blob

x

x

IfcCharacterSpacingSelect

x

deleted, funtionality moved to IfcSizeSelect

x

IfcCharacterStyleSelect

x

select item changed from IfcColour to IfcTextStyleForDefinedFont

x

x

IfcCurveStyle

x

only global units are used and measures are given in target plot scale

Name

x

deleted, now moved to supertype IfcPresentationStyle

x

x

WR11

x

WR added to enforce a positive length measure or 'by layer'

IfcCurveStyleFontPattern

VisibleSegmentLength

x

attribute type changed to IfcLengthMeasure

WR01

x

WR added to ensure a value >= 0.

IfcExternallyDefinedSurfaceStyle

x

correction of misspellt name IfcExternallyDefinedSufaceStyle

x

x

IfcFillAreaStyle

Name

x

deleted, now moved to supertype IfcPresentationStyle

x

WR12

x

rule added to restrict externally defined hatch styles to one instance

WR13

x

rule added to allow either external defined or internal defined hatch styles

IfcFillAreaStyleHatching

PatternStart

x

attribute has been made optional

x

PointOfReferenceHatchLine

x

attribute has been made optional

x

WR21

x

rule added to control hatch line distance

WR22

x

rule added to enforce 2D point

WR23

x

rule added to enforce 2D point

IfcHatchLineDistanceSelect

x

new SELECT item added

x

x

IfcPixelTexture

Pixel

x

Datatype changed to Binary for better encoding of the hex values

x

IfcPresentationStyle

x

New abstract supertype

Name

x

New attribute, promoted from subtypes

IfcSizeSelect

x

SELECT item IfcMeasureWithUnit removed, IfcDescriptiveMeasure added

x

x

IfcStyledItem

Item

x

attribute made optional

x

WR12

x

rule added to prevent an IfcStyledItem to style another IfcStyledItem

IfcSurfaceStyle

Name

x

deleted, now moved to supertype IfcPresentationStyle

x

x

WR11

x

rule added

WR12

x

rule added

WR13

x

rule added

WR14

x

rule added

WR15

x

rule added

IfcSurfaceStyleWithTextures

Textures

x

aggregate changed to LIST

HasTextureCoordinates

x

inverse attribute deleted

IfcSymbolStyle

Name

x

deleted, now moved to supertype IfcPresentationStyle

IfcTextAlignment

x

definition and where rule changed at the defined type

IfcTextDecoration

x

new defined type

IfcTextTransformation

x

new defined type

IfcTextStyle

x

x

x

Name

x

deleted, now moved to supertype IfcPresentationStyle

x

TextFontStyle

x

new attribute type:TextFontSelect added for reusable font definiton

TextStyle

x

attribute TextStyles renamed intoTextStyle, now optional 0:1

TextCharacterAppearance

x

attribute CharacterGlypphArearance renamed

IfcTextStyleSelect

x

removing IfcTextStyleWithMirror, adding IfcTextStyleModel

IfcTextStyleForDefinedFont

x

new entity combining text color and background color

x

x

IfcTextStyleTextModel

x

new entity to allow for text box and spacing definitions following CSS model

x

IfcTextStyleWithBoxCharacteristics

x

x

x

CharacterSpacing

x

new attribute

IfcTextStyleWithMirror

x

deleted, no occurrence specific information in reusable font definition

x

IfcTextStyleWithSpacing

x

deleted, functionality moved to IfcTextStyleWithBoxCharacteristics.

x

IfcTextureCoordinate

moved to IfcPresentationDefinitionResource schema

Texture

x

attribute Texture deleted

x

x

IfcPresentationDefinitionResource

IfcAnnotationCurveOccurrence

WR31

x

WR added (compliance with P46 original)

IfcAnnotationFillArea

Boundaries

x

attribute replaced by a differentiation of inner and outer boundaries

x

x

OuterBoundary

x

new attribute

InnerBoundaries

x

new attribute

IfcAnnotationFillAreaOccurrence

FillStyleTarget

x

attribute made optional

x

GlobalOrLocal

x

new attribute to determine global or local origin for hatching

x

x

WR31

x

WR added (compliance with P46 original)

IfcAnnotationSurface

x

New entity for solids and surfaces with texture coordinates

x

TextureCoordinates

x

New attribute to assign texture coordinates

IfcAnnotationSurfaceOccurrence

WR31

x

WR added (compliance with P46 original)

IfcAnnotationSymbolOccurrence

WR31

x

WR added (compliance with P46 original)

IfcAnnotationTextOccurrence

WR31

x

WR added (compliance with P46 original)

IfcBoxAlignment

x

new defined type

IfcTextFontSelect

x

renamed from IfcFontSelect

IfcTextLiteral

x

Font

x

attribute Font deleted, now handled at IfcTextStyle

Alignment

x

deleted, moved down to subtype IfcTextliteralWithExtent

IfcTextLiteralWithExtent

x

Alignment

x

new attribute, demoted from supertype IfcTextLiteral

WR31

x

WR added (disallow IfcPlanarBox for extent)

IfcTextureMap

TextureMaps

x

New attribute to assign texture mapping

VertexBasedTextures

x

Attribute deleted

IfcVertexBasedTextureMap

VertexBasedGeometry

x

attribute deleted (moved to IfcTextureMap)

x

x

TexturePoints

x

attribute added

x

x

TextureVertices

x

list changed from 1:? to 3:?

IfcPresentationDimensioningResource

IfcDimensionPair

x

new entity

x

IfcPresentationOrganisationResource

IfcAnnotationFillAreaOccurrence

FillStyleTarget

x

attribute made optional

x

GlobalOrLocal

x

attribute added

x

IfcPresentationLayerAssignment

Identifier

x

added and promoted from subtype, was LayerNumber

IfcPresentationLayerWithStyle

x

remaned from IfcPresentationLayerAssignmentWithStyle

x

x

LayerNumber

x

promoted to supertype

LayerOnInAllViews

x

deleted, since IFC does not define paper space

LayerFrozenInAllViews

x

deleted, since IFC does not define paper space

LayerColour

x

changed into a more general LayerStyle

LayerCurveWidth

x

deleted, covered by LayerStyle

LayerCurveFont

x

deleted, covered by LayerStyle

IfcPresentationResource

IfcFontStyle

x

new defined type

IfcFontVariant

x

new defined type

IfcFontWeight

x

new defined type

IfcPreDefinedTextFont

x

subtype IfcTextStyeFontModel added

x

IfcTextFontName

x

new defined type

IfcTextFontSelect

x

SELECT type renamed from IfcFontSelect

IfcTextStyleFontModel

x

new entity to allow for text font definitions following CSS model

x

IfcProfilePropertyResource

IfcStructuralProfileProperties

CentreOfGravityInX

x

new attribute, moved from various profile definitions

x

x

CentreOfGravityInY

x

new attribute, moved from various profile definitions

x

x

IfcProfileResource

IfcParameterizedProfileDef

x

all profiles now used as being centric to the bounding box

IfcArbitraryOpenProfileDef

new subtype IfcCenterLineProfileDef added

WR11

x

WR to allow area profile type for subtype

IfcAsymmetricIShapeProfileDef

CentreOfGravityInY

x

attribute made optional, profile inserted now at centre of bounding box

x

IfcCenterLineProfileDef

x

new profile for thin metal plates

x

Thickness

x

new attribute

IfcCraneRailAShapeProfileDef

CentreOfGravityInY

x

attribute made optional, profile inserted now at centre of bounding box

x

IfcCraneRailFShapeProfileDef

CentreOfGravityInY

x

attribute made optional, profile inserted now at centre of bounding box

x

IfcCShapeProfileDef

CentreOfGravityInX

x

attribute made optional, profile inserted now at centre of bounding box

x

IfcLShapeProfileDef

CentreOfGravityInX

x

attribute made optional, profile inserted now at centre of bounding box

x

WR3

x

WR deleted

IfcTShapeProfileDef

CentreOfGravityInY

x

attribute made optional, profile inserted now at centre of bounding box

x

IfcUShapeProfileDef

CentreOfGravityInX

x

attribute made optional, profile inserted now at centre of bounding box

x

IfcPropertyResource

IfcPropertySingleValue

NominalValue

x

Attribute changed to an optional attribute

x

IfcRepresentationResource

IfcGeometricRepresentationContext

x

only one instance is allowed and mandatory for the model view

ContextType

x

only 'Model', and 'NotDefined' allowed as values

(INV) HasSubContexts

x

new inverse attribute to navigate to the set of sub contexts

IfcGeometricRepresentationSubContext

TargetScale

x

attribute now used to define the target plot scale

IfcMaterialDefinitionRepresentation

x

new entity to assign presentation to material definitions

x

IfcProductDefinitionShape

(INV) ShapeOfProduct

x

new inverse attribute to link the product shape to the product

WR11

x

WR added to enforce a shape model representation

IfcProductRepresentation

x

subtype IfcMaterialDefinitionRepresentation added

x

IfcRepresentation

x

marked for being changed into an ABSTRACT type

(INV) LayerAssignments

x

Inverse attribute added to access the layer from the representation

(INV) RepresentationMap

x

New inverse attribute to the representation map where it maybe used

IfcRepresentationContext

x

marked for being changed into an ABSTRACT type

IfcShapeAspect

ShapeRepresentation

x

promoted to new supertype IfcShapeModel to apply to topology as well

x

IfcShapeModel

x

new abstract entity grouping geometry and topology representations

IfcStyleModel

x

new abstract entity grouping pure style information (e.g. for material)

IfcStyledRepresentation

WR21

x

where rule added to force Items to be of type IfcStyledItem

IfcRepresentationContextSameWCS

x

global rule enhanced

IfcShapeRepresentationTypes

x

global function enhanced and corrected

IfcTopologyResource

IfcFaceBound

WR1

x

rule deleted, no restriction of loops to be face bounds

CORE LAYER

IfcKernel

IfcObject

x

now subtyped from IfcObjectDefinition

IfcObjectDefinition

x

new abstract supertype of objects and type objects

IfcProject

WR32

x

WR added to enforce hierarchy of geometric representation contexts

WR33

x

WR added to enforce project to only be root of decomposition (if any)

IfcPropertySetDefinition

x

subtype IfcDoorOccurrenceProperties added

x

IfcRelAssociates

WR12

x

Where rule changed to allow association to type objects

IfcTypeObject

x

now subtyped from IfcObjectDefinition

HasPropertySets

x

Aggregation type changed from List to Set

IfcPlacementNotShared

x

global rule deleted, now covered by IfcObjectPlacement.PlacesObjects

IfcProductExtension

IfcBuildingElementProxyType

x

New entity to define type definitions for building element proxies

x

IfcBuildingElementProxyTypeEnum

x

New enumeration to define specific building element proxy types

x

IfcDistributionElementType

x

Abstract entity made non-abstract

x

IfcElement

(INV) HasStructuralMember

x

New inverse attribute to connect structural members to elements

(INV) ReferencedInStructure

x

New inverse relationship to new IfcRelReferencedInSpatialStructure

IfcFurnishingElementType

x

Abstract entity made non-abstract

x

IfcGrid

Geometric use

x

new geometric use definition to attach geometric curve set to IfcGrid

WR2

x

Where rule deleted

IfcRelCoverSpaces

x

New relationship to assign coverings to spaces

x

IfcRelReferencedInSpatialStructure

x

New relationship to reference elements in spatial structures

x

IfcSpace

(INV) HasCoverings

x

New inverse relationship to IfcRelCoversSpaces

IfcSpaceType

x

New entity to define type definitions for spaces

x

IfcSpaceTypeEnum

x

New enumeration to define specific space types

x

IfcSpatialStructureElement

(IN) ReferencesElements

x

New inverse relationship to new IfcRelReferencedInSpatialStructure

IfcSpatialStructureElementType

x

New abstract entity for types of spatial elements

IfcSystem

WR1

x

rule deleted, no restriction on system members

INTEROPERABILITY LAYER

IfcSharedBldgElements

IfcCurtainWallType

x

New entity

x

PredefinedType

x

New attribute

x

IfcCurtainWallTypeEnum

x

New enumeration

x

IfcDoorLiningProperties

WR31

x

modified, now allows for optional depth as a variable depth

WR32

x

modified, now allows for optional depth as a variable depth

IfcMemberTypeEnum

x

Enumerator MULLION added

x

IfcPlateTypeEnum

x

Enumerator CURTAIN_PANEL, SHEET added

x

IfcSlabTypeEnum

x

New enumerator "baseslab" added

x

IfcWallTypeEnum

x

New enumerator "elemented wall" added

x

IfcWindowLiningProperties

WR31

x

Where rule changed to allow for variable depth

WR32

x

New where rule

WR33

x

New where rule

WR34

x

New where rule

IfcSharedBldgServiceElements

IfcSoundProperties

x

PointOfMeasurement

x

Attribute deleted

x

x

DOMAIN LAYER

IfcStructuralAnalysisDomain

IfcOrientationSelect

x

New select type to provide two ways for orientation values

IfcRelAssociatesProfileProperties

ProfileOrientation

x

New attribute to provide an beta angle for curve members

x

x

IfcRelConnectsWithEccentricity

x

new entity to explicitly define eccentricity

x

ConnectionConstraint

x

new attribute

IfcRelConnectsStructuralElement

x

new entity to associate analytical and physical element

x

RelatingElement

x

new attribute

RelatedStructuralElement

x

new attribute

IfcStructuralActivityAssignmentSelect

x

select changed to include IfcElement, not IfcBuildingElement

IfcStructuralAction

ProjectedOrTrue

x

attribute demoted to subtypes

IfcStructuralMember

(INV) ReferencesElement

x

new inverse attribute

IfcStructuralLinearAction

ProjectedOrTrue

x

new attribute, demoted from supertype

IfcStructuralPlanarAction

ProjectedOrTrue

x

new attribute, demoted from supertype