1.1 Reference View

Purpose of the Reference View

With the publication of the IFC4 release, that has been accepted as ISO 16739 by the International Standardization Organization, several enhancements and improvements over the previous IFC releases are now available for improved open BIM interoperability using the IFC protocol.

The main purpose of this document is to define a standardized subset of the IFC4 schema, a Model View Definition MVD, that is particularly suitable for all BIM workflows that are based on reference models, where the exchange is mainly one-directional. Here requested modifications of the BIM data, mainly of the shape representation, are handled by a change request to the original author, and changes are not executed upon the imported IFC data with the intent to be sent back to the original source.

Examples of this reference workflow are:

• Coordination planning (combining different discipline specific IFC models for visual checking)
• Clash detection (finding clashes between different discipline specific IFC models)
• Background reference (loading an IFC model, usually from a different discipline) as a linked model
• Quantity take-off (determine the quantities of the various model elements with the IFC model)
• Construction sequencing (taking the IFC model and associating it to a construction schedule)
• Visual presentation (for presenting the IFC model to a broad audience)

Common characteristics of the workflow using reference models are:

• The source of the BIM information remains with the originator
• The full parametric behaviour, and thereby the intellectual engineering property, remains with the originator
• The ownership of the model, and responsibility for its correctness, remains with the originator
• The original model is published as IFC4 Reference View model reflecting the as-is status
• The receiver of the IFC4 Reference View model has access to the full model content
• The receiver of the IFC4 Reference View is not supposed to modify the model
• The receiver of the IFC4 Reference View can analyse and extract the information of the model
• If the receiver suggests or demands a change, it has to be communicated as a change request to the originator
• The buildingSMART standard BCF (BIM Collaboration Format) is developed to efficiently support these change requests.

The Level of Detail of the shape representation and the Level of Information for the property content of the actual reference models depends on the source model. The buildingSMART standard IDM (Information Delivery Manual) can be used to determine the minimum content for a particular workflow support. The IFC4 Reference View allows rich content to be published.

Objective

The main objective of the IFC Reference View is the widest possible proliferation of IFC BIM data across a big range of software application types supporting different communication and collaboration workflows.

The IFC Reference View is characterized by the ability to publish BIM data following that subset of IFC definitions that enables semantically rish content of building data, and to some degree also other built environment data, to be exchanges with a streamlined geometric representation that is optimized for analysis and display, but excludes dimension-driven geometric parameters. The geometric representation is therefore suitable for all workflow scenarios, where the imported IFC model is displayed, analysed, compared, clashed, but not parametricly modified for futher work processes.

Semantic building data models being exchanged using the IFC4 Reference View would typically include:

• physical elements with explicit geometry, properties, quantities, material, and classification
• types of elements with associated physical elements to group common definitions (geometry, properties, material, and classification)
• spatial elements (spaces, zones) with explicit geometry, properties, quantities, and classification
• spatial structure elements (site, building, story), but also spatial zones for non-vertical construction
• element breakdown structure between physical elements (assemblies, sub-assemblies, parts)
• spatial breakdown structure between spatial elements (spatial decomposition of building, story or zones)
• spatial containment structure between spatial elements and physical elements (elements in spatial zone)
• logical system structure and assignment (physical elements assigned to systems and sub systems)
• topological structure of system networks (element to port, and port to port, relationship)
• common context of the building model, providing units, coordinate system and GIS positions
• general object identification using globally unique identifier

Additional capabilities for enriching the semantic information exposed by the IFC4 Reference View can be defined as an Add-on Model View Definition. Forseeable examples are capturing 4D models with the addition of the work schedule related entities, or 5D models with the addition of construction resource related entities.

Workflow support

The overall goal of the IFC Reference View is to provide workflows where building information models are to be consumed by the widest array of software applications that do not require modifying geometry. Such applications enable viewing, estimating, building, operating, and other downstream analysis.

EXAMPLE One target scenario is an architect providing building design information to a contractor or facility manager. It is expected that the resulting geometry would reflect sufficient realism for viewing in software (dimensions, normals, colors, textures), but not of rendering quality for artistic presentations (lighting, shader effects, curve interpolation, rasterizing).

To support the widest array of consuming applications, the resulting schema should be as limited as possible for representing geometry in the interest of minimizing resources required of application developers. Such schema should also be as compact as possible to enable downstream use on mobile devices with limited network bandwidth. It is proposed that the resulting geometry is limited to triangles with normal vectors, colour and texture coordinates and simple sweeped solids with applied colour and texture.

Compatibility concerns

As the IFC4 Reference View is new (there is no corresponding concept in the IFC2x3 Coordination View), there is no constraint for compatibility, and the resulting schema will leverage new triangulation definitions in IFC4 to support more efficient data transfer.

The second Model View Definition that is proposed in parallel to the IFC4 Reference View, the IFC4 Design Transfer View, is an extension of this model view. In other words, the IFC4 Reference View is a true subset of the IFC4 Design Transfer View.

Complying software interfaces, that implements import of the IFC4 Design Transfer View, shall also be able to correctly import IFC4 Reference View data sets. But not vice versa, a complying software interface, that implements import of the IFC4 Reference View will not be capable to import IFC4 Design Transfer View data sets. It is however required that a compliant software interface for importing IFC4 Reference View displays an agreed error messange showing the IFC version, and the IFC Model View Definition of the imported IFC file, that does not match "IFC4 Reference View" with an explanation, that a non-compatible IFC file has been received.

NOTE The correct error message and the link to further information on the buildingSMART website explaining the purpose of the different IFC Model View Deinitions need to be agreed upon.

General scope definition

The general scope defines the main functionalities of the IFC4 Reference View as an overview. It includes a complete listing of the model elements and model element types that are included in the IFC4 Reference View Model View Definition.

NOTE  The Model elements are refered to as "Root Concepts" within the Model View Definition specification, being the indiviudual root elements, that contain the attributes, geometric shapes, dynamic property sets and other semantic information that are combined and expressed as "Concepts". The common definition of a "Concept", that is applicable to many "Root Concepts" is called a "Concept Template".

The detailed scope of the IFC4 Reference View is determined by the concept templates that are included. A detailed description of each concept template is provided by Chapter 4 "Fundamental concepts and assumptions".

Model elements

The main components of the IFC4 Reference View are the semantic model elements that carry a predefined meaning. The complete breakdown of all model elements declared in IFC4 are also known as the IFC4 built-in classification following an element by function classification.

In addition to each of the model elements shown here in the subsequent tables, each Model element maybe further specialized by its "PredefinedType", or even a user defined type.

EXAMPLE An IfcFireSuppressionTerminal is a specific model element, that may be further specialized using its PredefinedType enumeration being: a sprinkler, a hose reel, a fire hydrant, or a breeching inlet. If a proper predefined type is not yet included in the specification, a user defined type can be assigned as well.

Architectural model elements

LEGEND  * new in IFC4, + includes IfcRampFlight, ++ includes IfcStairFlight

Structural model elements

NOTE Architectural elements, like IfcWall, IfcSlab, IfcBeam, etc, are also used in structural models, and vice versa

Building service model elements

The model element specialization structure within the building service domain within the IFC standard is organized accoring to its function within a distribution system, and not primarily according to the main building service discipline, within it is mainly used.

The internal specialization structure for building service elements at its highest level is also independed of the fluid used within the distribution system:

• flow segments
• flow fittings
• flow terminals
• flow moving devices
• flow storage devices
• flow controller
• energy conversion device
• distribution control elements

The following tables intents to assign the model elements to the various disciplines within the building service system domain.

LEGEND  * new in IFC4, note all building service occurrence elements are new, the previous IFC2x3 release only included the generic occurrence elements: IfcFlowSegment, IfcFlowFitting, IfcFlowTerminal, IfcFlowMovingDevice, IfcFlowStorageDevice, IfcFlowController, IfcEnergyConversionDevice, and IfcDistributionControlElement. Those are still available as general purpose MEP Model elements, but its use is discouraged.

Other model elements

LEGEND  * new in IFC4, + also used as general element proxy ++ provided as stub for future infrastructure extensions

Spatial elements, spatial structure and grouping elements

LEGEND  * new in IFC4, + provided as a stub for non vertical constructions

Model element types

Model element types are part of the IFC4 Reference View. They enable to describe and share common model element information that are shared by multiple occurrences of the same type. Sharable type information includes:

• Geometric shape representation;
• Property information;
• Material information.

EXAMPLE A particular air outlet as an article, with its shape, its material and its manufacturer information being described once as a type and then having several occurrences, each placed within the building, referencing the same type and hence its shape, material and properties.

Most of the Model elements introduced in the previous session have a corresponding Model element type, such as:

• IfcWall — IfcWallType;
• IfcFastener — IfcFastenerType;
• IfcFan — IfcFanType.

Only the following spatial structure elements IfcSite, IfcBuilding, IfcBuildingStorey, the grouping elements IfcGroup, IfcZone, IfcSystem (and subtypes), and the IfcDistributionPort and IfcGrid do not have matching element types.

Overview on major concepts used

Object attribute

All model elements, listed in the previous section, are defined by several generic and direct object attributes, some specific model elements do carry additional direct attributes. The usage of the direct generic attributes is defined within the following concept templates (see also Chapter 4 "fundamental concepts and assumptions"):

• "Software Identity", it defines how to apply the Globally Unique Id and how to compress it during exchange;
• " User Identity", it defins the meaning of Name, Description, LongNameand Tagattributes;
• " Object Occurrence Predefined Type", it defines how to use the PredefinedTypeand in case of user defined types, how to assign the user defined type information within the ObjectTypeattribute for occurrences of model elements;
• " Element Type Predefined Type" it defines how to use the PredefinedTypeand in case of user defined types, how to assign the user defined type information within the ElementTypeattribute for types of model elements.

Project context

There is a single instance of IfcProjectwithin each IFC data set. It sets the context for the exchange, including units, geometric context, global positioning and classification systems used within the data set. The usage of the project context is defined within the following concept templates (see also Chapter 4 "fundamental concepts and assumptions"):

• "Project Units", declaration of the units used within this data set, all geometric representations are forced to use the global units (e.g. for length measure and plane angle measure), property values may override global unit declarations;
• "Project Representation Context", declaration of the 3D and 2D representation contexts, including precision factors;
• "Project Global Positioning" (new in IFC4), positioning the project engineering coordinate system (right handed Cartesian coordinate system) within a global coordinate reference system;
• "Project Classification Information", providing the name and version information about the classification systems used within the data set.

Object definition

A main objective of the IFC4 Reference View is to enable rich information content for each model element. Model element occurrences can refer to their model element types for sharing common information. General properties are attached to model elements as property sets, either directly to the model element occurrence, or to its type. Individual model element occurrences can hold their quantities, if those are pre-calculated by the sender of the IFC data set. The usage of the object definition is defined within the following concept templates (see also Chapter 4 "fundamental concepts and assumptions"):

• "Object Typing", associates the Model element occurrences with the corresponding element type;
• "Property Sets", assigns dynamically defined property sets, holding set of individual properties, to the model element occurrences of element type;
• "Quantity Sets", assigns dynamically defined quantity sets, holding set of individual quantities, to the model element occurrences.

Object typing

The contept template describes the mechnism of associating model element occurrences to the corresponding type and the way and restrictions of overriding type based properties by properties directly assigned to the model element occurrences.

Property sets

Property sets hold, as the name suggests, a set of properties grouped by a common theme. Each individual property has:

• a name
• an optional description
• a value, or number of values, of a given datatype
• a unit or the information of being unitless

The semantic meaning of each property is provided by its name. Properties, that are semantically declared within the scope of the IFC4 Reference View, are based on a property definition template that is published as an instrict part of the Model View Definition. Extensions to the property definitions can also be defined outside the property definition scope of the IFC4 Reference View, however the name prefix for property sets "Pset_" is restricted to properties defined within the original scope of IFC.

There are two ways to declare property templates:

• using the Property Set Definition PSD schema, an XML schema developed independent of the IFC specification,
• using the newly introduced IFC4 property set template and property template

NOTE The PSD Schema has been used since many earlier versions of the IFC standard and has a broad legancy. The newer property set template definitions are now part of the IFC schema and can therefore be embedded within an IFC data set directly. Both schemas can be mapped without information loss.

Quantity sets

Quantity sets hold, as the name suggests, a set of quantities pre calculated for the model element occurrence. Each individual quantity has:

• a name
• an optional description
• a value of a given datatype corresponding to the quantity measure (length, area, volume, weight, time
• a unit
• a quantity formula, describing how the quantity value was calculated

The semantic meaning of each qualtity is provided by its name. Quantities, that are semantically declared within the scope of the IFC4 Reference View, are based on a quantity definition template that is published as an instrict part of the Model View Definition. Extensions to the quantity definitions can also be defined outside the quantity definition scope of the IFC4 Reference View, however the name prefix for quantity sets "Qto_" is restricted to quantities defined within the original scope of IFC.

Object association

In addition to the Property sets and the Quantity sets, also a classification reference to an external classification system can be assigned, and material as either single material, a material constituent sets or an material layer sets aor material profile sets combining material information with dimensions can be associated to one or many model elements.

NOTE Material dimensions are layer thicknesses, or profile geometries for e.g. a column with an embedded steel profile and a concrete protection. Within the IFC4 Reference View, such material dimensions are used exclusively as alphanumeric information, and not as part of a dimension driven parametric shape representation.

The usage of the object association is defined within the following concept templates (see also Chapter 4 "fundamental concepts and assumptions"):

• "Material Association"; assigns a material (or material set - constituent, layer, profile) to one or several model elements (either to element occurrences, or as shared material information to element types).
• "Classification Association"; assignes a classification reference to one or several model elements.

Product shape

The first main objective of the IFC4 Reference View is to enable the exchange of highly accurate, not non-parametric, geometric representations of the model elements. Each model element is placed directly or indirectly within the project coordinate system, defining its own object coordinate system. The geometric representation items describing its shape are positioned within this object coordinate system.

In order to minimize the effort for receiving and interpreting the geometic representations by the receiving software systems, in terms of development effort, processing power and loading times, the complexity and variety of geometric models has been minimized for the IFC4 Reference View.

Product placement

Each model element defines its own object coordinate system. The placement is defined by the following concept template:

• "Product Local Placement", creating an object coordinate system for the shape representation of the model element, either absolutely to the project engineering coordinate system, or relatively to another object coordination system.

Product geometric representation

In scope of geometric shape representations of the 3D body geometry of physical and spatial elements are the following concept templates:

• "Body Tessellation Geometry", using tessellated geometry in form of triangulated tessellations for describing the body shape of the model element;
• "Body SweptSolid Geometry"; using extruded solid geometry or revolved solid geometry for describing the body shape of the model element;
• "Body AdvancedSweptSolid Geometry"; using advanced swept solid geometry of circular cross sections for describing the body shape of the model element, only the swept disk solid is in scope;

It is the default geometric representation of all model elements, allowing for a surface model representation with an indicator for closed shells (and therefore true volumes). The tessellated representation offers a very efficient way of exchanging 3D shape date, both for data set sizes and for processing time. Optionally the face normals can be exchanged as well.

Since curved shapes would lead to very densely triangulated areas, the following swept solid based representations are also in scope of the IFC4 Reference View, balancing simplicity and compactness of representation:

All other geometric models are out of scope of the IFC4 Reference View, in particular Boolean operations required for Constructive Solid Geometry CSG.

NOTE The IFC2x3 Coordination View included CSG capabilities, the IFC4 Reference View therefore imposes a more restricted geometric representation of model elements. The IFC4 Design Transfer View should be used, if more complex geometric representations are required by the workflow. In particular, if a dimension-driven parametric representation, used by the IFC4 standard case elements, is needed.

The geometric shape representation can either be directly assigned to a model element, or to its type. In case of type-based geometry, a the following representation type is used at the model element using the following concept template:

• " Mapped Geometry", mapped representation defined at the corresponding element type. A mapped representation uses Cartesian transformation operations to place the type-based geometry within its object coordinate system.

As an exception, the following elements, IfcGrid, IfcSpace, and IfcSpatialZone may have an additional foot print 2D geometry (in case of IfcGridthis is the only geometric representation. It is described in the following concept template:

• " FootPrint Geometry", defining a 2D shape representation within the XY plane of the object coordinate system.

Geometric presentation

Visual appearance is an important factor for the communication process using BIM data. The objective is not to support photo-realistic rendering of reference models, but to use color, basic rendering, and texture information to add visually accessible meaning to the model elements.

In scope of presentation capabilities for the appearance of model element shapes are the following partial concept templates:

• " Surface Style Shading", applying a single coloring for each solid;
• " Surface Style Rendering", applying a single rendering (color, transparency, reflection, etc.) for each solid;
• " Surface ", applying a single texture for each solid according to a texture mapping based on the solid type;
• " Suface Style Tessellation", applying a color and/or texture for each face of a tessellated solid.

The visually adaquate presentation of model elements is constraint by the shape representation

• for tessellated geometry: color per face, texture per face
• for swept solid geometry: color and rendering information per solid, texture applied to solid using standard mapping

Object Composition

The object composition functionality describes the product breakdown structure of model elements within an IFC data set, with separate breakdown structures for physical elements and spatial elements. Physical element structures describe parts and assemblies, spatial element structures describe vertical structures (for buildings) and horizontal structures (for other assets - as a stub in this release). A specific type of decomposition is the voiding - a subtraction of a void from a physical element. Another specific type is the nesting of ports within a distribution elements.

The usage of the object association is defined within the following concept templates (see also Chapter 4 "fundamental concepts and assumptions"):

• "Element Decomposition", creating a hierarchical product breakdown structure relationship between assemblies and parts;
• " Spatial Decomposition", creating a hierarchical spatial decomposition relationship between spatial structure elements;
• " Element Voiding", creating a voiding relationship between a physical element and penetrating voids - within the scope of the IFC4 Reference View this relationship is a logical relationship, the void is already part of the geometry of the physical element,
• " Port Nesting", creating an 1:N relationship between the physical element and one or many ports defining inlets or outlets - used for distribution elements.

Object Assignment

The object assignment defines the assignment of objects, such as a link between model elements to groups, tasks or resources. Only the grouping assignment is in scope of the IFC4 Reference View and defined within the following concept template:

• " Group Assignment", Assignment of one or several model elements to a group. It includes the more specific assignments of Grouping General, Grouping to System, and Grouping to Zones.

Object Connectivity

The object connectivity defines the interlinkage between model elements. Examples are the link between physical elements and the spatial structure, where they are located, of the connection betwee the two ports of two consecutive distribution elements.

The usage of the object association is defined within the following concept templates (see also Chapter 4 "fundamental concepts and assumptions"):

• " Spatial Structure", defines the containment of a physical element within a spatial container;
• " Port Connectivity", defines the connection and the direction of flow between two ports of consecutive distribution elements;
• " Building Service Connectivity", links a spatial or distribution system to a spatial structure (such as a building section);
• " Element Filling", links a filling (usually a door or window) to an opening (usually in a wall or slab).

IfcActuator

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcActuator
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcAirTerminalBox
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcAirTerminal
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcAirToAirHeatRecovery
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcAlarm
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcAudioVisualAppliance
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcBeam
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcBoiler
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcBuilding
Building Identity	\IfcBuilding.LongName \IfcLabel	The usage of building address, elevation measures and composition type is governed by this concept.
Spatial Composition	\IfcSpatialElement.Decomposes[*] \IfcRelAggregates.RelatingObject \IfcProject.Name	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	\IfcObjectDefinition.IsDecomposedBy[*] \IfcRelAggregates.RelatedObjects[*] \IfcSpatialElement.Name \IfcLabel	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).
	\IfcSpatialElement.ContainsElements[*] \IfcRelContainedInSpatialStructure.RelatedElements[*] \IfcProduct	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	\IfcObject	The following standard property sets are defined for IfcBuilding.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \IfcLabel	The following base quantities are defined for IfcBuilding.
Product Local Placement	\IfcProduct.ObjectPlacement \IfcLocalPlacement.RelativePlacement \IfcAxis2Placement3D	The local placement for IfcBuilding is defined by its supertype IfcProduct. It is defined by the IfcLocalPlacement, which establishes the local coordinate system that is referenced by all geometric representations. The PlacementRelTo relationship of IfcLocalPlacement shall point to the subtype of IfcSpatialStructureElement that is referenced by the Spatial Decomposition concept (usually of type IfcSite). If the IfcBuilding is the uppermost spatial structure element, the PlacementRelTo shall not be set.
	\IfcProduct.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.RepresentationIdentifier \IfcLabel	The optional identifier of the representation as used within a project.
Structure Service Connectivity	\IfcSpatialElement.ServicedBySystems[*] \IfcRelServicesBuildings.RelatingSystem \IfcSystem.Name \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.
	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject.ObjectType \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.
	\IfcObject.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcBuildingElementPart
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcBuildingStorey
Storey Identity	\IfcBuildingStorey.LongName \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.
Spatial Composition	\IfcSpatialElement.Decomposes[*] \IfcRelAggregates.RelatingObject \IfcProject.Name	NOTE  By using the inverse relationship IfcBuildingStorey.Decomposes it references (IfcBuilding || IfcBuildingStorey) through IfcRelAggregates.RelatingObjectIfcBuildingStorey, the referenced IfcBuildingStorey needs to have a different and higher CompositionType, i.e. COMPLEX (if the other IfcBuildingStorey has ELEMENT), or ELEMENT (if the other IfcBuildingStorey has PARTIAL).
Spatial Decomposition	\IfcObjectDefinition.IsDecomposedBy[*] \IfcRelAggregates.RelatedObjects[*] \IfcSpatialElement.Name \IfcLabel	NOTE  By using the inverse relationship IfcBuildingStorey.IsDecomposedBy it references IfcBuildingStorey || IfcSpace through IfcRelAggregates.RelatedObjects. If it refers to another instance of IfcBuildingStorey, the referenced IfcBuildingStorey needs to have a different and lower CompositionType, i.e. ELEMENT (if the other IfcBuildingStorey has COMPLEX), or PARTIAL (if the other IfcBuildingStorey has ELEMENT). NOTE  Multi storey spaces shall be spatially contained by only a single building storey, usually it is the building storey where the base of the space lies.
Spatial Container	\IfcSpatialElement.ContainsElements[*] \IfcRelContainedInSpatialStructure.RelatedElements[*] \IfcProduct	If there are building elements and/or other elements directly related to the IfcBuildingStorey (like most building elements, such as walls, columns, etc.), they are associated with the IfcBuildingStorey by using the objectified relationship IfcRelContainedInSpatialStructure. The IfcBuildingStorey references them by its inverse relationship: IfcBuildingStorey.ContainsElements -- referencing any subtype of IfcProduct (with the exception of other spatial structure element) by IfcRelContainedInSpatialStructure.RelatedElements. Elements can also be referenced in an IfcBuildingStorey, for example, if they span through several storeys. This is expressed by using the objectified relationship IfcRelReferencedInSpatialStructure. Systems, such as building service or electrical distribution systems, zonal systems, or structural analysis systems, relate to IfcBuildingStorey by using the objectified relationship IfcRelServicesBuildings.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Placement	\IfcProduct.ObjectPlacement \IfcLocalPlacement.RelativePlacement \IfcAxis2Placement3D	The local placement for IfcBuildingStorey 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 IfcBuilding, or of type IfcBuildingStorey (e.g. to position a building storey relative to a building storey complex, or a partial building storey to a building storey). If the relative placement is not used, the absolute placement is defined within the world coordinate system.
	\IfcProduct.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.RepresentationIdentifier \IfcLabel	The optional identifier of the representation as used within a project.
	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject.ObjectType \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.
	\IfcObject.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcBurner
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCableCarrierFitting
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCableCarrierSegment
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCableFitting
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCableSegment
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcChiller
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcChimney
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCoil
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcColumn
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCommunicationsAppliance
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCompressor
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCondenser
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcController
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCooledBeam
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCoolingTower
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCovering
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcCurtainWall
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDamper
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDiscreteAccessory
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDistributionElement
	\IfcObject	The IFC class identifier indicating the subtype of object.
Component to Distribution System	\IfcDistributionElement.HasAssignments[*] \IfcRelAssignsToGroup.RelatingGroup \IfcDistributionSystem.Name \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.
Port Nesting	\IfcDistributionElement	The IFC class identifier indicating the subtype of object.
Clearance Geometry	\IfcElement.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.ContextOfItems \IfcGeometricRepresentationContext	Definition of the representation context for which the different subtypes of representation are valid.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDistributionPort
Product Local Placement	\IfcProduct.ObjectPlacement \IfcLocalPlacement.RelativePlacement \IfcAxis2Placement3D	The placement of a port indicates the position and orientation of how it may connect to a compatible port on another product. The placement shall be relative to the nesting IfcDistributionElement, IfcDistributionElementType, or enclosing IfcDistributionPort. The Location is the midpoint of the physical connection, unless otherwise indicated by cardinal point on a material profile. The Axis points in the direction of the physical connection away from the product if FlowDirection equals SOURCE (or SOURCEANDSINK or NOTDEFINED), or points opposite direction (to the product) if the FlowDirection equals SINK. NOTE  The rationale for positioning the Axis in the direction of flow is to allow for the same geometry to be used, such as for connectors with polarized cross-section. The RefDirection points in the direction of the local X axis of the material profile, where the local Y axis points up if looking towards the Axis where the local X axis points right. Upon connecting elements through ports with rigid connections, each object shall be aligned such that the effective Location, Axis, and RefDirection of each port is aligned to be equal (with exception for circular profiles where the RefDirection need not be equal).
Port Connectivity	\IfcDistributionPort.ConnectedFrom[*] \IfcRelConnectsPorts.RelatingPort \IfcDistributionPort	IfcDistributionPort may be connected to other objects as follows using the indicated relationship: IfcDistributionPort (IfcRelConnectsPorts) : Indicates a connection to another port having the same type and opposite flow direction. For port connections between elements, the RelatingPort is set to a port having FlowDirection=SOURCE and the RelatedPort is set to a port having FlowDirection=SINK. For aggregation scenarios, ports on a device may be mapped to aggregated devices within, in which case ports on the outer device indicate a single FlowDirection but have an additional connection internally to a port on an aggregated inner device. Refer to IfcUnitaryEquipment for an example. IfcDistributionElement (IfcRelConnectsPortToElement): For dynamic ports, indicates the containing element. Figure 139 illustrates distribution port connectivity. Figure 139 — Distribution port connectivity
	\IfcObject	The IFC class identifier indicating the subtype of object.
Port to Distribution System	\IfcDistributionPort.HasAssignments[*] \IfcRelAssignsToGroup.RelatingGroup \IfcDistributionSystem.Name \IfcLabel	The IfcDistributionPort is assigned to the distribution system where it plays its role as inlet or outlet.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDistributionSystem
	\IfcObject	The IFC class identifier indicating the subtype of object.
Aggregation
Group Assignment	\IfcGroup.IsGroupedBy[*] \IfcRelAssignsToGroup.RelatedObjects[*] \IfcProduct	For the most common case of an IfcDistributionElement subtype containing ports of a particular PredefinedType that all belong to the same distribution system, the IfcDistributionElement is assigned to the IfcDistributionSystem via the IfcRelAssignsToGroup relationship, where IfcDistributionPort's are implied as part of the corresponding system based on their PredefinedType. An IfcDistributionElement may belong to multiple systems, however only one IfcDistributionSystem of a particular PredefinedType. For rare cases where an IfcDistributionElement subtype contains ports of the same PredefinedType yet different ports belong to different systems, alternatively each IfcDistributionPort may be directly assigned to a single IfcDistributionSystem via the IfcRelAssignsToGroup relationship, where the PredefinedType must match. Such assignment indicates that the IfcDistributionSystem assigned from the IfcDistributionPort overrides any such system of the same PredefinedType assigned from the containing IfcDistributionElement, if any. Additionally, an IfcDistributionSystem may in turn be assigned to an IfcDistributionPort indicating the host or origination of the system using IfcRelAssignsToProduct. EXAMPLE  A gas-powered hot water heater may have three ports: GAS, DOMESTICCOLDWATER, and DOMESTICHOTWATER. The heater is a member of two systems (GAS and DOMESTICCOLDWATER), and hosts one system (DOMESTICHOTWATER) at the corresponding port. Figure 140 illustrates a distribution system for an electrical circuit. Figure 140 — Distribution system assignment
System Element Attributes	\IfcSystem.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDoor
Door Attributes	\IfcDoor.Tag \IfcIdentifier	The opening direction is determined by the local placement of IfcDoor and the OperationType of the IfcDoorType as shown in Figure 133. The IfcDoorTypeOperationEnum defines the general layout of the door type and its symbolic presentation. Depending on the enumerator, the appropriate instances of IfcDoorLiningProperties and IfcDoorPanelProperties are attached in the list of HasPropertySets. The IfcDoorTypeOperationEnum mainly determines the hinge side (left hung, or right hung), the operation (swinging, sliding, folding, etc.) and the number of panels. NOTE  There are different definitions in various countries on what a left opening or left hung or left swing door is (same for right). Therefore the IFC definition may derivate from the local standard and need to be mapped appropriately. Opening directions Definitions Reference to other standards The door panel (for swinging doors) opens always into the direction of the positive Y axis of the local placement. The determination of whether the door opens to the left or to the right is done at the level of the IfcDoorType. Here it is a left side opening door given by IfcDoorType.OperationType = SingleSwingLeft refered to as LEFT HAND (LH) in US * refered to as DIN-R (right hung) in Germany If the door should open to the other side, then the local placement has to be changed. It is still a left side opening door, given by IfcDoorType.OperationType = SingleSwingLeft refered to as RIGHT HAND REVERSE (RHR) in US * refered to as DIN-R (right hung) in Germany If the door panel (for swinging doors) opens to the right, a separate door style needs to be used (here IfcDoorTypee.OperationType = SingleSwingRight) and it always opens into the direction of the positive Y axis of the local placement. refered to as RIGHT HAND (RH) in US * refered to as DIN-L (left hung) in Germany If the door panel (for swinging doors) opens to the right, and into the opposite directions, the local placement of the door need to change. The door style is given by IfcDoorType.OperationType = SingleSwingRight. refered to as LEFT HAND REVERSE (LHR) in US * refered to as DIN-L (left hung) in Germany * it assumes that the 'inside/private/primary' space is above (top in the pictures) and the 'outside/public/secondary' space is below (bottom in the pictures). Figure 133 — Door swing NOTE  The OverallWidth and OverallHeight parameters are for informational purpose only.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Material Constituent Set with Override	\IfcElement.HasAssociations[*] \IfcRelAssociatesMaterial.RelatingMaterial \IfcMaterialConstituentSet.MaterialConstituents[*] \IfcMaterialConstituent.Name \IfcLabel	The material of the IfcDoor is defined by the IfcMaterialConstituentSet or as fall back by IfcMaterial and attached by the IfcRelAssociatesMaterial relationship. It is accessible by the inverse HasAssociations relationship. The following keywords for IfcMaterialConstituentSet.MaterialConstituents[n].Name shall be used: 'Lining' - to indicate that the material constituent applies to to the door lining 'Framing' - to indicate that the material constituent applies to to the door framing, if not provided, the 'Lining' material information applied to frams as well 'Glazing' - to indicate that the material constituent applies to to the glazing as well If the fall back single IfcMaterial is referenced, it applies to the lining and framing of the door.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDuctFitting
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDuctSegment
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcDuctSilencer
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcElectricAppliance
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcElectricDistributionBoard
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcElectricFlowStorageDevice
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcElectricGenerator
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcElectricMotor
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcElectricTimeControl
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

All general-case subtypes of IfcElement are included in this model view; standard-case and elemented-case subtypes are excluded.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcElement	All general-case subtypes of IfcElement are included in this model view; standard-case and elemented-case subtypes are excluded.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcProduct.ObjectPlacement \IfcLocalPlacement.RelativePlacement \IfcAxis2Placement3D	Placement of elements is defined by a local placement (a transformation matrix relative to): the spatial container (if not part of an assembly) provided by the relationship IfcRelContainedInSpatialStructure.RelatingSpatialStructure being a subtype of IfcSpatialElement, in most cases, IfcBuildingStorey the parent aggregation element (if it is an aggregated part) provided by the relationship IfcRelAggregates.RelatingObject being a subtype of IfcElement The local placement shall always be relative.
CoG Geometry	\IfcProduct.Representation \IfcProductDefinitionShape.Name	The 'CoG', Center of Gravity, shape representation is used as a means to verify the correct import by comparing the CoG of the imported geometry with the explicily provided CoG created during export.
Box Geometry	\IfcProduct.Representation \IfcProductDefinitionShape.Representations['Box'] \IfcShapeRepresentation.ContextOfItems \IfcGeometricRepresentationContext	EXAMPLE  Any IfcElement may be represented by a bounding box, which shows the maximum extend of the body within the object coordinate system established by the IfcObjectPlacement. As shown in Figure 111, the bounding box representation is given by an IfcShapeRepresentation that includes a single item, an IfcBoundingBox. Figure 111 — Building element box representation
Body Solid Geometry General	\IfcElement.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.ContextOfItems \IfcGeometricRepresentationContext	Definition of the representation context for which the different subtypes of representation are valid.
Body Tessellation Geometry	\IfcElement.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.ContextOfItems \IfcGeometricRepresentationContext	The default geometric representation of any IfcElement within this model view is a single or multiple tessellated item. The supported tessellation is a triangulated face set, defined by indices into a Cartesian point list. Optionally normals per vertex can be included as well.
Body SweptSolid PolyCurve Geometry	\IfcElement.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.ContextOfItems \IfcGeometricRepresentationContext	The IfcElement can be geometrically represented by a single or multiple swept solid. In this case, both extruded and revolved solids are supported. The cross section of the swept solid is provided by a poly curve, having straight and circular arc segments. The cross section may have inner loops that result in holes of the resulting swept solid.
Mapped Geometry	\IfcProduct.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.ContextOfItems \IfcGeometricRepresentationContext	Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented using the 'MappedRepresentation'. This shall be supported as it allows for reusing the geometry definition of a type at all occurrences of the same type. The results are more compact data sets. The same constraints, as given for 'Tessellation', 'SweptSolid', and 'AdvancedSweptSolid' geometric representation, shall apply to the IfcRepresentationMap.
Product Geometry Layer	\IfcProduct.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.LayerAssignments[*] \IfcPresentationLayerAssignment	Assignment of the whole representation to a single or multiple layer(s). The LayerAssigments can be overridden by LayerAssigments of the IfcRepresentationItem's within the list of Items.
Product Geometry Colour	\IfcProduct.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.Items[*] \IfcSolidModel.StyledByItem[*] \IfcStyledItem.Styles[*] \IfcSurfaceStyle	Representation styles which are assigned, either to an geometric representation item, or to a material definition.
Spatial Containment	\IfcElement.ContainedInStructure[*] \IfcRelContainedInSpatialStructure.RelatingStructure \IfcSpatialElement.Name \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.
Element Composition	\IfcElement.Decomposes[*] \IfcRelAggregates.RelatingObject \IfcElement.Name \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.
Element Decomposition	\IfcElement.IsDecomposedBy[*] \IfcRelAggregates.RelatedObjects[*] \IfcElement.Name \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.
Element Voiding	\IfcElement.HasOpenings[*] \IfcRelVoidsElement.RelatedOpeningElement \IfcOpeningElement.PredefinedType \IfcOpeningElementTypeEnum	Predefined generic type for an opening that is specified in an enumeration. There may be a property set given specificly for the predefined types.
Material Single	\IfcElement.HasAssociations[*] \IfcRelAssociatesMaterial.RelatingMaterial \IfcMaterial.HasProperties[*] \IfcMaterialProperties.Name \IfcIdentifier	The name given to the set of properties.
Material Constituent	\IfcElement.HasAssociations[*] \IfcRelAssociatesMaterial.RelatingMaterial \IfcMaterialConstituentSet.MaterialConstituents[*] \IfcMaterialConstituent.Name \IfcLabel	The name by which the material constituent is known.
Classification	\IfcObject.HasAssociations[*] \IfcRelAssociatesClassification.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcEngine
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcEvaporativeCooler
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcEvaporator
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcFan
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcFastener
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcFilter
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcFireSuppressionTerminal
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcFlowInstrument
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcFlowMeter
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcFooting
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcFurniture
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcGeographicElement
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcGrid
Grid Attributes	\IfcGrid.PredefinedType \IfcGridTypeEnum	Predefined types to define the particular type of the grid.
Product Local Placement	\IfcProduct.ObjectPlacement \IfcLocalPlacement.RelativePlacement \IfcAxis2Placement3D	Geometric placement that defines the transformation from the related coordinate system into the relating. The placement can be either 2D or 3D, depending on the dimension count of the coordinate system.
FootPrint GeomSet Geometry	\IfcProduct.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.RepresentationIdentifier \IfcLabel	The 2D geometric representation of IfcGrid is defined using the 'GeometricCurveSet' geometry. The following attribute values should be inserted IfcShapeRepresentation.RepresentationIdentifier = 'FootPrint'. IfcShapeRepresentation.RepresentationType = 'GeometricCurveSet'. The following constraints apply to the 2D representation: The IfcGeometricCurveSet shall be an (and the only) Item of the IfcShapeRepresentation. It should contain an IfcGeometricCurveSet containing subtypes of IfcCurve, each representing a grid axis. Applicable subtypes of IfcCurve are: IfcPolyline, IfcCircle, IfcTrimmedCurve (based on BaseCurve referencing IfcLine or IfcCircle), and IfcOffsetCurve2D. Each subtype of IfcCurve may have a curve style assigned, using IfcStyledItem referencing IfcCurveStyle. Optionally the grid axis labels may be added as IfcTextLiteral, and they may have text styles assigned, using IfcStyledItem referencing IfcTextStyle. As shown in Figure 31, the IfcGrid defines a placement coordinate system using the ObjectPlacement. The XY plane of the coordinate system is used to place the 2D grid axes. The Representation of IfcGrid is defined using IfcProductRepresentation, referencing an IfcShapeRepresentation, that includes IfcGeometricCurveSet as Items. All grid axes are added as IfcPolyline to the IfcGeometricCurveSet. Figure 117 — Grid layout     As shown in Figure 32, the attributes UAxes and VAxes define lists of IfcGridAxis within the context of the grid. Each instance of IfcGridAxis refers to the same instance of IfcGridAxis refers to the same instance of IfcCurve (here the subtype IfcPolyline) that is contained within the IfcGeometricCurveSet that represents theIfcGrid. Figure 118 — Grid representation
Spatial Containment	\IfcElement.ContainedInStructure[*] \IfcRelContainedInSpatialStructure.RelatingStructure \IfcSpatialElement.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcHeatExchanger
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcHumidifier
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcInterceptor
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcJunctionBox
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcLamp
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcLightFixture
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcMechanicalFastener
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcMedicalDevice
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcMember
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcMotorConnection
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcObject
Object User Identity	\IfcObject.Name \IfcLabel	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.
	\IfcObject.ObjectType \IfcLabel	This concepts utilizes the additional level of specializing objects. At the level of subtypes, an PredefinedType enumeration attribute is introduced to select a more specific object occurrence category. If the current precompiled enumeration does not include the specific category, a user defined value can be set.
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \IfcLabel	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.
Property Sets for Objects	\IfcObject	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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcOutlet
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcPile
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcPipeFitting
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcPipeSegment
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcPlate
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcProject
Project Units	\IfcContext.UnitsInContext \IfcUnitAssignment.Units[*] \IfcDerivedUnit.UnitType \IfcDerivedUnitEnum	Name of the derived unit chosen from an enumeration of derived unit types for use in IFC models.
Project Representation Context 3D	\IfcContext.RepresentationContexts[*] \IfcGeometricRepresentationContext.ContextIdentifier \IfcLabel	The main representation context defined at the IfcProject shall be a 3D representation concept.
	\IfcContext.RepresentationContexts[*] \IfcGeometricRepresentationContext.HasCoordinateOperation[*] \IfcMapConversion.Eastings \IfcLengthMeasure	The representation context of the project refers to a global positioning, i.e. the local engineering coordinate system of the project has a mapping to a defined projected coordinate system (a rectangular map coordinate system, as used in GIS systems)
Project Type Definitions	\IfcContext.Declares[*] \IfcRelDeclares.RelatedDefinitions[*] \IfcTypeObject	Set of object or property definitions that are assigned to a context and to which the unit and representation context definitions of that context apply.
Project Classification Information	\IfcContext.HasAssociations[*] \IfcRelAssociatesClassification.RelatingClassification \IfcClassification.Source \IfcLabel	Source (or publisher) for this classification.
	\IfcObjectDefinition.IsDecomposedBy[*] \IfcRelAggregates.RelatedObjects[*] \IfcSpatialElement.Name \IfcLabel	The IfcProject is used to reference the root of the spatial structure of a building or other construction project (that serves as the primary project breakdown and is required to be hierarchical). The spatial structure elements are linked together, and to the IfcProject, by using the objectified relationship IfcRelAggregates. IfcProject.Decomposes -- shall be NIL, i.e. the IfcProject shall be on top of the root of the spatial structure tree. IfcProject.IsDecomposedBy -- referencing (IfcSite || IfcBuilding || IfcSpatialZone) by using IfcRelAggregates.RelatedObjects. The IfcSite, IfcBuilding, or IfcSpatialZone being referenced shall be the root of the spatial structure.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcProtectiveDevice
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcProtectiveDeviceTrippingUnit
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcPump
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcRailing
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Material Constituent Set with Override	\IfcElement.HasAssociations[*] \IfcRelAssociatesMaterial.RelatingMaterial \IfcMaterialConstituentSet.MaterialConstituents[*] \IfcMaterialConstituent.Name \IfcLabel	The material of the IfcRailing is defined by the IfcMaterialConstituent or as fallback by IfcMaterial, and it is attached either directly or at the IfcRailingType.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcRamp
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \IfcLabel
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Element Decomposition	\IfcElement.IsDecomposedBy[*] \IfcRelAggregates.RelatedObjects[*] \IfcElement.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcRampFlight
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Element Composition	\IfcElement.Decomposes[*] \IfcRelAggregates.RelatingObject \IfcElement.Name \IfcLabel	The IfcRampFlight shall only be used within the component breakdown structure of an IfcRamp.
Spatial Containment	\IfcElement.ContainedInStructure[*] \IfcRelContainedInSpatialStructure.RelatingStructure \IfcSpatialElement.Name \IfcLabel	Since the IfcRampFlight is always a component of IfcRamp it shall not have an independent spatial containment relationship to a spatial structure.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcReinforcingBar
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcReinforcingMesh
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcRoof
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Element Decomposition	\IfcElement.IsDecomposedBy[*] \IfcRelAggregates.RelatedObjects[*] \IfcElement.Name \IfcLabel	Geometric representation by aggregated elements If the IfcRoof has components (referenced by SELF\IfcObject.IsDecomposedBy) then no independent geometric representation shall defined for the IfcRoof. The IfcRoof is then geometrically represented by the geometric representation of its components. The components are accessed via SELF\IfcObject.IsDecomposedBy[1].RelatedObjects. The geometric representations that are supported for the aggregated elements are defined with each element. See geometric use definition for IfcSlab, IfcBeam, IfcColumn, IfcBuildingElementPart and other subtypes of IfcBuildingElement. Figure 134 illustrates roof placement, with an IfcRoof defining the local placement for all aggregated elements. Figure 134 — Roof placement

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcRoot
Identity	\IfcRoot.GlobalId \IfcGloballyUniqueId	Globally unique ID, as compressed uuid, is assigned to each subtype of IfcRoot.
Revision Control	\IfcRoot.OwnerHistory \IfcOwnerHistory.OwningUser \IfcPersonAndOrganization.ThePerson \IfcPerson.Identification \IfcIdentifier	Ownership, history, and merge state is captured using IfcOwnerHistory.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcSanitaryTerminal
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcSensor
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcShadingDevice
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcSite
Site Attributes	\IfcSite.LongName \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.
Spatial Composition	\IfcSpatialElement.Decomposes[*] \IfcRelAggregates.RelatingObject \IfcProject.Name	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).
Spatial Decomposition	\IfcObjectDefinition.IsDecomposedBy[*] \IfcRelAggregates.RelatedObjects[*] \IfcSpatialElement.Name \IfcLabel	By using the inverse relationship IfcSite.IsDecomposedBy it references (em>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).
	\IfcSpatialElement.ContainsElements[*] \IfcRelContainedInSpatialStructure.RelatedElements[*] \IfcProduct	Set of products, which are contained within this level of the spatial structure hierarchy.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Product Local Placement	\IfcProduct.ObjectPlacement \IfcLocalPlacement.RelativePlacement \IfcAxis2Placement3D	Geometric placement that defines the transformation from the related coordinate system into the relating. The placement can be either 2D or 3D, depending on the dimension count of the coordinate system.
	\IfcProduct.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.RepresentationIdentifier \IfcLabel	The optional identifier of the representation as used within a project.
	\IfcObject.Name \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.
	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject.ObjectType \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcSlab
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
Quantity Sets	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcSolarDevice
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.

Field	Mapping	Definition	MEP Reference Exchange	Structural Reference Exchange	Architectural Reference Exchange
(Query)	\IfcSpace
Space Attributes	\IfcSpace.LongName \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.
Object Typing	\IfcObject.IsTypedBy[*] \IfcRelDefinesByType.RelatingType \IfcTypeObject.Name \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.
Property Sets for Objects	\IfcObject	The IFC class identifier indicating the subtype of object.
	\IfcObject.IsDefinedBy[*] \IfcRelDefinesByProperties.RelatingPropertyDefinition \IfcElementQuantity.Name \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.
Spatial Decomposition	\IfcObjectDefinition.IsDecomposedBy[*] \IfcRelAggregates.RelatedObjects[*] \IfcSpatialElement.Name \IfcLabel	By using the inverse relationship IfcSpace.Decomposes it references IfcSite || IfcBuildingStorey by IfcRelAggregates.RelatingObject.
	\IfcSpatialElement.ContainsElements[*] \IfcRelContainedInSpatialStructure.RelatedElements[*] \IfcProduct	Set of products, which are contained within this level of the spatial structure hierarchy.
Product Local Placement	\IfcProduct.ObjectPlacement \IfcLocalPlacement.RelativePlacement \IfcAxis2Placement3D	The local placement for IfcSpace is defined at 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 local placement of the IfcSpatialStructureElement of type IfcBuildingStorey or IfcSite if relative placement is used. If the relative placement is not used, the absolute placement is defined within the world coordinate system.
FootPrint GeomSet Geometry	\IfcProduct.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.RepresentationIdentifier \IfcLabel	The following constraints apply to the 2D representation: An IfcBoundedCurve is required, using IfcPolyline for faceted space contours or IfcCompositeCurve for space contours with arc segments. For spaces with inner boundaries, a set of IfcBoundedCurve's is used, that should be grouped into an IfcGeometricCurveSet.   EXAMPLE  Figure 125 shows a two-dimensional bounded curve representing the foot print of IfcSpace. Figure 125 — Space footprint
Body SweptSolid PolyCurve Geometry	\IfcElement.Representation \IfcProductDefinitionShape.Representations[*] \IfcShapeRepresentation.ContextOfItems \IfcGeometricRepresentationContext	The following constraints apply to the 'Body' 'SweptSolid' representation: Solid: IfcExtrudedAreaSolid is required, Profile: IfcArbitraryClosedProfileDef and IfcArbitraryProfileDefWithVoids shall be supported. The profile outline and inline curves are defined using IfcIndexedPolyCurve. Extrusion: The extrusion direction shall be vertically, i.e., along the positive Z Axis of the co-ordinate system of the containing spatial structure element. Figure 126 shows an extrusion of an arbitrary profile definition with voids into the swept area solid of IfcSpace. Figure 126 — Space body swept solid
	\IfcObject.Name \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.
	\IfcObject.ObjectType \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.