ARCHITECTURE LAYER

New

Schema

Changed

affects P21 file -->

Entity / Function

Deleted

not upward compatible

Attribute / WR

Usage

Change description

RESOURCE LAYER

IfcGeometricConstraintResource

IfcGridPlacement

x

Documentation updated xy plane of grid placement shall be co-planar to IfcGrid xy plane

IfcGeometryResource

IfcCurveBoundedPlane

x

Documentation updated coordinate system for OuterBoundary and InnerBoundaries clarified

IfcTrimmedCurve

x

Documentation updated parameter range for circular arcs clarified

IfcBuildAxes

Function modified to improve compatibility with EXPRESS parsers

IfcCurveDim

Function modified to improve compatibility with EXPRESS parsers

IfcScalarTimesVector

Function modified to improve compatibility with EXPRESS parsers

IfcNormalise

Function modified to improve compatibility with EXPRESS parsers

IfcVectorDifference

Function modified to improve compatibility with EXPRESS parsers

IfcVectorSum

Function modified to improve compatibility with EXPRESS parsers

IfcMaterialResource

IfcMaterialLayerSetUsage

x

Documentation updated correction of wall example and new example for slab and roof slab

IfcMeasureResource

IfcCompoundPlaneAngleMeasure

x

Changed to LIST[3:4] OF INTEGER to accommodate fractions of seconds

IfcCorrectUnitAssignment

x

Function modified to improve compatibility with EXPRESS parsers

IfcDeriveDimensionalExponents

x

Function corrected

IfcPresentationAppearanceResource

IfcCurveStyle

x

Documentation updated curve style measures defined as representing model space

IfcCurveStyleFontAndScaling

x

Documentation updated purpose of the scaling factor clarified

IfcFillAreaStyle

x

Documentation updated fill area style measures defined as representing model space

WR13

x

Where rule corrected Background colour and hatching can now be assigned

IfcFillAreaStyleHatching

x

Documentation updated Use of PointOfReferenceHatchLine marked as deprecated

IfcProfileResource

IfcArbitraryOpenProfileDef

x

Documentation updated Semantic definition of WR11 reflects subtype IfcCentreLineProfileDef

IfcRepresentationResource

IfcGeometricRepresentationContext

x

Documentation updated Definition corrected, wrong statement about optional WCS deleted

IfcRepresentation

AssignedItem

x

Spelling corrected (affects only case sensitive implementations) Assigneditems --> AssignedItems

IfcShapeRepresentation

x

Documentation updated Annotation2D added to the list of RepresentationType

IfcShapeRepresentationTypes

x

Documentation updated Annotation2D added to the list of RepresentationType

CORE LAYER

IfcKernel

IfcProject

x

Documentation corrected

IfcRelDecomposes

WR32

x

Where rule deleted

WR33

x

Where rule deleted

IfcProductExtension

x

Semantic definitions of entities within the schema have been revisited and updated in general, only major documentation updates are listed below.

IfcBuilding

x

Documentation updates and figure added Quantity use definition updated.

IfcBuildingElement

x

Documentation updated Change representation identifier for bounding box from 'Body' to 'Box' Add objectified relationship capabilities to documentation.

IfcBuildingElementProxy

x

Documentation updated Representation types "GeometricCurveSet" and "GeometricSet" separated, property set Pset_BuildingElementProxyCommon added.

IfcBuildingStorey

x

Documentation updates and figure added Quantity use definition updated.

IfcCovering

x

Documentation updated Guidance on assignment to spaces added, Quantity use definition updated, Type use definition enhanced, RepresentationIdentifier and Type added for shape representation

WR61

Where rule added

IfcCoveringType

x

Documentation updated Guidance on material association added

IfcDistributionElement

x

Documentation updated type use definition and quantity use definition added, geometry use definition revised.

IfcElement

x

Documentation updated Use of Pset_Drafting marked as being deprecated

IfcElementAssembly

x

Documentation updated Containment use definition included, local placement use definition corrected informal proposition for aggregation relationship added

IfcFeatureElement

x

Documentation updated Containment use definition added

IfcFurnishingElement

x

Documentation updates Additional shape representations added

IfcGrid

x

Documentation updates Shape representations for grid corrected and clarification added

IfcOpeningElement

x

Documentation updated Use of containment in spatial structure corrected

IfcProjectionElement

x

Documentation updated Use of containment in spatial structure corrected, quantity definition added

IfcRelAssociatesMaterial

x

Documentation updated Informal proposition to not use MLS usage for types added

IfcRelContainedInSpatialStructure

x

Documentation updated Clarification of use of containment versus reference

IfcRelCoversBldgElements

x

Documentation updated Clarification of element versus space coverings added

IfcRelCoversSpaces

x

Documentation updated Clarification of element versus space coverings added

IfcRelFillsElement

Documentation updated Figure to explain usage added

IfcRelVoidsElement

Documentation updated Figure to explain usage added

IfcSite

x

Documentation updated shape representation type "FootPrint" added, figure added

IfcSharedBldgElements

IfcBeam

x

Documentation updated Steel profiles added to SweptSolid shape representation

IfcColumn

x

Documentation updated Steel profiles added to SweptSolid shape representation

IfcDoor

x

Documentation updated Profile and Footprint representation added to shape representation Definition of overall heigth and length corrected.

IfcMember

x

Documentation updated Steel profiles added to SweptSolid shape representation

IfcNoOfLayers

x

Deleted because no longer needed (see IfcRelConnectsPathElements)

IfcPlate

x

Added Pset_PlateCommon

IfcPlateType

WR1

x

Where rule deleted no mandatory assignment of material information anymore

IfcRailing

WR61

Where rule added

IfcRelConnectsPathElements

x

Deleted derived attributes RelatedLayerCount and RelatingLayerCount (and related function IfcNoOfLayers)

IfcSlab

x

Documentation updated material use definition added for IfcMaterialLayerSetUsage, agreement on material layer set and usgae for slab type and occurrence added

WR61

x

Where rule WR2 corrected and renamed WR61

IfcSlabType

x

Documentation updated Guidance on property sets and material association added

IfcWall

x

Documentation updated Non vertical extrusion added to the geometry use case

IfcWallStandardCase

x

Documentation updated Vertical extrusion added to the requirements for standard walls, agreement on material layer set and usage for wall type and occurrence added

IfcWallType

x

Documentation updated Guidance on property sets and material association added

IfcWindow

x

Documentation updated Profile and Footprint representation added to shape representation Opening direction and hidge side explained

IfcSharedBldgServiceElements

x

Documentation updated Revised schema overview to provide more information about the functional groupings of types, occurrences and performance history instances. Removed blank EXPRESS-G pages in documentation.

IfcDistributionChamberElement

x

Documentation updated Add Property Set Use definitions and Geometry Use definitions

IfcDistributionChamberElementType

x

Documentation updated More descriptive definitions of Type added

IfcDistributionChamberElementTypeEnum

x

Documentation updated Add Property Set Use definitions and updated Geometry Use definitions

IfcDistributionFlowElement

x

Documentation updated More descriptive definitions of Occurrence added

IfcDistributionPort

x

Documentation updated Updated and extended example of connectivity between distribution elements

IfcEnergyConversionDevice

x

Documentation updated Add Property Set Use definitions

IfcEnergyConversionDeviceType

x

Documentation updated More descriptive definitions of Type added

IfcFlowController

x

Documentation updated Add Property Set Use definitions

IfcFlowControllerType

x

Documentation updated More descriptive definitions of Type added

IfcFlowFitting

x

Documentation updated Add Property Set Use definitions

IfcFlowFittingType

x

Documentation updated More descriptive definitions of Type added

IfcFlowMovingDevice

x

Documentation updated Add Property Set Use definitions

IfcFlowMovingDeviceType

x

Documentation updated More descriptive definitions of Type added

IfcFlowSegment

x

Documentation updated Add Property Set Use definitions and updated Geometry Use definitions

IfcFlowSegmentType

x

Documentation updated More descriptive definitions of Type added

IfcFlowStorageDevice

x

Documentation updated Add Property Set Use definitions

IfcFlowStorageDeviceType

x

Documentation updated More descriptive definitions of Type added

IfcFlowTerminal

x

Documentation updated Add Property Set Use definitions

IfcFlowTerminalType

x

Documentation updated More descriptive definitions of Type added

IfcFlowTreatmentDevice

x

Documentation updated Add Property Set Use definitions

IfcFlowTreatmentDeviceType

x

Documentation updated More descriptive definitions of Type added

IfcRelFlowControlElements

x

Documentation updated Clarified definition

IfcSoundProperties

x

Documentation updated Optional PointOfMeasurement attribute has been removed. Use an instance of IfcAnnotation to identify the location at which sound properties have been recored.

Pset_DistributionFlowElementCommon

x

New property set for distribution flow element occurrences

DOMAIN LAYER

IfcHvacDomain

x

Documentation updated Revised schema overview to provide more information about the functional groupings of types

IfcAirTerminalBoxType

x

Documentation updated More descriptive definitions of Type added

IfcAirTerminalType

x

Documentation updated More descriptive definitions of Type added

IfcAirToAirHeatRecoveryType

x

Documentation updated More descriptive definitions of Type added

IfcBoilerType

x

Documentation updated More descriptive definitions of Type added

IfcChillerType

x

Documentation updated More descriptive definitions of Type added

IfcCoilType

x

Documentation updated More descriptive definitions of Type added

IfcCompressorType

x

Documentation updated More descriptive definitions of Type added

IfcCondenserType

x

Documentation updated More descriptive definitions of Type added

IfcCooledBeamType

x

Documentation updated More descriptive definitions of Type added

IfcCoolingTowerType

x

Documentation updated More descriptive definitions of Type added

IfcCoolingTowerTypeEnum

x

Documentation updated More descriptive definitions of Type added

IfcDamperType

x

Documentation updated More descriptive definitions of Type added

IfcDuctFittingType

x

Documentation updated More descriptive definitions of Type added

IfcDuctSegmentType

x

Documentation updated More descriptive definitions of Type added

IfcDuctSilencerType

x

Documentation updated More descriptive definitions of Type added

IfcEvaporativeCoolerType

x

Documentation updated More descriptive definitions of Type added

IfcEvaporatorType

x

Documentation updated More descriptive definitions of Type added

IfcFanType

x

Documentation updated More descriptive definitions of Type added

IfcFilterType

x

Documentation updated More descriptive definitions of Type added

IfcFlowMeterType

x

Documentation updated More descriptive definitions of Type added

IfcGasTerminalType

x

Documentation updated More descriptive definitions of Type added

IfcHeatExchangerType

x

Documentation updated More descriptive definitions of Type added

IfcHumidifierType

x

Documentation updated More descriptive definitions of Type added

IfcPipeFittingType

x

Documentation updated More descriptive definitions of Type added

IfcPipeSegmentType

x

Documentation updated More descriptive definitions of Type added

IfcPipeSegmentTypeEnum

x

Documentation updated More descriptive definitions of Type added

IfcPumpType

x

Documentation updated More descriptive definitions of Type added

IfcSpaceHeaterType

x

Documentation updated More descriptive definitions of Type added

IfcTankType

x

Documentation updated More descriptive definitions of Type added

IfcTubeBundleType

x

Documentation updated More descriptive definitions of Type added

IfcUnitaryEquipmentType

x

Documentation updated More descriptive definitions of Type added

IfcValveType

x

Documentation updated More descriptive definitions of Type added

IfcVibrationIsolatorType

x

Documentation updated More descriptive definitions of Type added

IfcStructuralAnalysisDomain

IfcStructuralAnalysisModel

x

Clarified grouping mechanism

IfcStructuralCurveMember

x

Amended attribute definition

IfcStructuralCurveTypeEnum

x

Added documentation of enumeration items

IfcStructuraItem

x

Corrected object placement

IfcStructuralLinearAction

x

Amended topology use definition for application to building elements

IfcStructuralLoadGroup

x

Relaxed type of Coefficient to IfcRatioMeasure

x

Added standard values of attribute Purpose and clarified all other attribute definitions

IfcStructuralPlanarAction

x

Amended topology use definition for application to building elements

IfcStructuralPointAction

x

Amended topology use definition for application to building elements

IfcStructuralSurfaceMember

x

Amended attribute definition

IfcStructuralSurfaceTypeEnum

x

Amended attribute definition