prEN ISO 23143-3

• Abstract:

  This document outlines the conceptual framework and methodology for linking abstract concepts between BIM and GIS standards to facilitate BIM/GIS interoperability. ; This document provides the mechanisms to establish links between abstract concepts in both domains in terms of metamodels, abstract conceptual schemas and application schemas.

• Status: Not Published
• Publication Date: 05-Mar-2028
• ICS: 35.240.67 - IT applications in building and construction industry
• ICS: 35.240.70 - IT applications in science
• Technical Committee: CEN/TC 442 - Building Information Modelling (BIM)
• Drafting Committee: CEN/TC 442 - Building Information Modelling (BIM)
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 13-Aug-2026
• Due Date: 18-Dec-2025
• Completion Date: 13-Aug-2026
• Ref Project: oSIST prEN ISO 23143-3:2026 - Information exchange between BIM and GIS - Part 3: Linking abstract concepts in BIM and GIS standards (ISO/DIS 23143-3:2026)

SLOVENSKI STANDARD
01-oktober-2026
Izmenjava informacij med BIM in GIS - 3. del: Povezovanje abstraktnih konceptov v
standardih BIM in GIS (ISO/DIS 23143-3:2026)
Information exchange between BIM and GIS - Part 3: Linking abstract concepts in BIM
and GIS standards (ISO/DIS 23143-3:2026)
Informationsaustausch zwischen BIM und GIS - Teil 3: Verknüpfung abstrakter Konzepte
in BIM- und GIS-Standards (ISO/DIS 23143-3:2026)
Directives pour l’échange d'informations entre BIM et SIG - Partie 3: Titre manque
(ISO/DIS 23143-3:2026)
Ta slovenski standard je istoveten z: prEN ISO 23143-3
ICS:
35.240.67 Uporabniške rešitve IT v IT applications in building
gradbeništvu and construction industry
35.240.70 Uporabniške rešitve IT v IT applications in science
znanosti
91.040.01 Stavbe na splošno Buildings in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 23143-3
ISO/TC 59/SC 13
Information exchange between BIM
Secretariat: SN
and GIS —
Voting begins on:
Part 3: 2026-08-12
Linking abstract concepts in BIM
Voting terminates on:
2026-11-04
and GIS standards
ICS: 35.240.67; 35.240.70
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
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This document has not been edited by the ISO Central Secretariat.
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Reference number
ISO/DIS 23143-3:2026(en)
DRAFT
ISO/DIS 23143-3:2026(en)
International
Standard
ISO/DIS 23143-3
ISO/TC 59/SC 13
Information exchange between BIM
Secretariat: SN
and GIS —
Voting begins on:
Part 3:
Linking abstract concepts in BIM
Voting terminates on:
and GIS standards
ICS: 35.240.67; 35.240.70
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
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NOTIFICATION OF ANY RELEVANT PATENT
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Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 23143-3:2026(en)
ii
ISO/DIS 23143-3:2026(en)
Contents Page
Foreword .v
Introduction .vi
0.1 General .vi
0.2 Propositions .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations . 2
5 Methodology . 2
5.1 Purposes .2
5.2 Principles .3
5.2.1 Use-case-driven information exchange .3
5.2.2 Semantic-based concept linking .3
5.2.3 Appropriate standard reference .3
5.2.4 Domain symmetry .4
5.2.5 Computer interpretability .4
5.3 Framework .4
5.4 Process for linking abstract concepts .5
5.5 Link types .6
6 Identification of abstract concepts . 7
6.1 Sources .7
6.2 Qualification of abstract concepts .7
7 Identification of common categories for cross-domain exchange . 8
7.1 General .8
7.2 Basic Context (CC1) .8
7.2.1 General .8
7.2.2 Spatial referencing .9
7.2.3 Temporal referencing .9
7.3 Object identity and classification (CC2) .9
7.3.1 General .9
7.3.2 Global identifier .9
7.3.3 Name .10
7.3.4 Object classification .10
7.4 Geometric characteristics (CC3) .10
7.4.1 General .10
7.4.2 Object positioning .10
7.4.3 Geometric elements .10
7.4.4 Topological elements .11
7.4.5 Appearance styles .11
7.5 Attribute characteristics (CC4) . .11
7.5.1 General .11
7.5.2 Attribute information exchange .11
7.6 Relationship structure (CC5) . 12
7.6.1 General . 12
7.6.2 Predicates . 13
8 Comparisons of abstract concepts .13
8.1 General . 13
8.2 Comparison of definitions and context . 13
8.3 Comparison of relationship with other concepts .14
8.4 Comparison of schema pattern and syntax .14
9 Establishment of the concept link representation(s) .15

iii
ISO/DIS 23143-3:2026(en)
9.1 General . 15
9.2 CLR representation framework . 15
9.2.1 Framework structure . 15
9.2.2 Relationship between CLR-C and CLR-S .16
9.2.3 Common concept categories in the framework .16
9.3 Concept link record (CLR-C) .16
9.3.1 Purpose .16
9.3.2 Attributes .17
9.4 Schema element link record (CLR-S) .17
9.4.1 Purpose .17
9.4.2 Attributes .18
Annex A (informative) Examples of concept link records and schema element link records . 19
Annex B (informative) Formal representation of CLR-C and CLR-S records . 47
Bibliography .58

iv
ISO/DIS 23143-3:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.
This document was prepared by ISO/TC 59, Buildings and civil engineering works, Subcommittee SC 13,
Organization and digitization of information about buildings and civil engineering works, including building
information modelling (BIM).
A list of all parts in the ISO 23143 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
ISO/DIS 23143-3:2026(en)
Introduction
0.1 General
In the built environment, building information modelling (BIM) is widely employed throughout the life
cycle of buildings and civil infrastructure as a digital methodology emphasizing information processing
at the project level. Geographic information systems (GIS) provide a standards-based framework for the
acquisition, modelling, management, analysis, and visualization of geospatial data. The ISO 19100 series of
International Standards establishes the conceptual and technical foundations for geographic information,
and has been widely applied in fields such as natural resources management, transportation, water
conservancy, and urban management.
BIM and GIS represent two distinct paradigms of spatial information modelling. BIM is oriented toward life
cycle management of works and structures, emphasizing the parametric definition of building components,
assembly relationships, and engineering semantics; GIS is oriented toward the spatiotemporal management
of spatial objects, emphasizing location, topology, and geographic semantics. The fundamental differences
in architecture and underlying philosophy reflect their respective domain requirements, conceptual
paradigms, and historical evolution. These differences shape the challenges of semantic interoperability.
The Industry Foundation Classes (IFC) are the most representative open data schema in the BIM domain.
IFC adopts an object-oriented design in which construction elements (e.g. walls, doors) are organized via
dedicated relationship entities into hierarchical and associative structures. The ISO 19100 series for GIS
likewise adopts an object-oriented approach, representing real-world objects or phenomena as features,
using UML as the schema language, and providing flexible mechanisms to describe geometry, attributes, and
relationships.
Against the backdrop of the demand for information exchange, although BIM and GIS differ significantly,
their intersection can still be identified: the description of the objective world. Regardless of how different
their perspectives are, both BIM and GIS strive to embody human perception of the objective world through
computer-readable datasets. This kind of perception has an objective consistency (e.g., urban patterns,
building shapes, etc.). Without such consistency, the foundation for information exchange would be lost. On
this basis, they are often needed to be integrated in large-scale infrastructure projects or city information
models.
ISO/TR 23262:2021 identifies interoperability opportunities between BIM and GIS by examining the
similarities and differences between BIM and GIS. In that technical report, subclause 7.2 recommends
linking abstract concepts in BIM and GIS standards to support data exchange opportunities 1 and 2.
Within both BIM and GIS, abstract concepts (e.g. object, relation) are generalizations that capture common
patterns, rules, and structural principles. Based on them, the concrete concepts (e.g. bridge, road) are
derived and organized semantically. It is fundamental to recognize abstract concepts and establish linkages
between them, not only because they form part of exchanged information, but also to prevent fragmented
alignment of concrete concepts.
0.2 Propositions
When identifying and linking abstract concepts from BIM and GIS to guide information exchange, the
following basic propositions are taken into account in this document:
— Use case-driven scope. Information exchange between BIM and GIS serves use-case needs; the exchanged
information shall be bounded by the intended purposes of use.
— Heterogeneity. BIM and GIS differ in methodology and data models; lossless exchange is generally not
achievable, nor is it required.
— Interface over implementation. Exchange should follow an interface-oriented rather than an
implementation-oriented approach, focusing on “what” rather than “how.” It is unnecessary to exchange
all internal constructional relationships within each data schema. The source system is responsible for
generating and maintaining its internal relationships; the target system is responsible for consuming and

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ISO/DIS 23143-3:2026(en)
using the outcomes of those relationships. The responsibility of the exchange is to convey the semantic
results of relationships, not their implementation processes.
— Directionality and mode. Information flows in two directions, i.e., BIM-to-GIS and GIS-to-BIM, which
are not equivalent. Distinguish between initial (creation) exchange and maintenance (update) exchange.
In creation exchange, the target system may not yet contain source data and may lack the capability
to receive it. In maintenance exchange, the same object may be updated repeatedly; therefore, data
traceability is critical.
— Semantic alignment. To ensure precise alignment between abstract concepts, it is recommended to
define exchange relationships using a shared data dictionary and/or linked semantic models between
BIM and GIS (e.g. RDF-based semantic networks). This provides a robust foundation for machine-readable
semantic interoperability.
This document does not cover every abstract concept in all BIM and GIS standards; rather, it provides a
framework enabling domain experts to establish links between abstract concepts. Additionally, software
developers can use the concept link records defined in this document as a reference for implementing BIM–
GIS information exchange interfaces.

vii
DRAFT International Standard ISO/DIS 23143-3:2026(en)
Information exchange between BIM and GIS —
Part 3:
Linking abstract concepts in BIM and GIS standards
1 Scope
This document establishes a methodology for linking abstract concepts within Building Information
Modelling (BIM) and Geographic Information System (GIS) standards and specifies structural mechanisms
for organizing their link relationships, aiming to facilitate cross-domain information exchange.
Methodologies for the development of RDF that relate to BIM and GIS are not within the scope of this
document.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
[1]
For the purposes of this document, the terms and definitions given in ISO 12006-3:2022 , ISO 16739-1:2024
[2] [3] [4] [5]
, ISO 23387:2025 , ISO 19101-1:2014 , ISO 19109:2025 , ISO/DIS 23143-1, as well as the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
concept
unit of knowledge created by a unique combination of characteristics
[6]
[SOURCE: ISO 1087:2019 , 3.2.7, modified — Note 1 to entry and Note 2 to entry have been removed.]
3.2
abstract concept
concept (3.1) representing a generalization of common characteristics and relations
Note 1 to entry: An abstract concept is independent of specific instances or technical implementation.
Note 2 to entry: An abstract concept is typically defined in conceptual models such as classes, feature types, or
relationship types.
3.3
link
defined association between two entities
Note 1 to entry: An association can be directional or non-directional.

ISO/DIS 23143-3:2026(en)
3.4
information exchange
act of satisfying an information requirement or part thereof
[7]
[SOURCE: ISO 7817-1:2024 , 3.3, modified — The part of speech "verb" has been removed.]
3.5
data schema
physical implementation of a data model in a specific data management system
Note 1 to entry: A data schema can include implementation details such as data types, classifications, and access
controls.
[8]
[SOURCE: ISO/IEC 25642:2025 , 3.11]
4 Abbreviations
BIM Building Information Modelling
GIS Geographic Information System
GFM General Feature Model
IFC Industry Foundation Classes
5 Methodology
5.1 Purposes
Information exchange between BIM and GIS drives the needs of the two information systems to be able to
interpret the data received from each other. The domain-specific data describe the unique characteristics of
concepts within the respective conceptual models of the physical world.
The interpretation of the data are based on the concepts to which the data relate and the schema elements
defined for those concepts, so that the data retain the semantics defined in the original domains.
Existing BIM and GIS international standards have defined many abstract concepts independently. The
abstract concept linkage provides a shared semantic foundation between BIM and GIS standards, so
that concept correspondences can be systematically determined and concrete concepts can be aligned
accordingly for information exchange.
The purpose of linking concepts is to enable data flow between BIM and GIS to facilitate information
exchange. See Figure 1.
ISO/DIS 23143-3:2026(en)
Figure 1 — Purpose of linking concepts for information exchange between BIM and GIS
NOTE Concrete concepts are domain-dependent and represent realizations of abstract concepts at the
implementation level.
5.2 Principles
5.2.1 Use-case-driven information exchange
Use case requirements serve as the governing criterion for defining the scope of BIM-GIS information
exchange. As the two domains address distinct aspects of the built and natural environments, a clearly
defined scope is essential to ensure that concept alignment remains targeted and proportionate. Within this
scope, all applicable abstract concepts are identified and linked, to achieve focused and complete information
exchange. Concepts outside the scope boundary are excluded to reduce unnecessary complexity without
compromising the fitness for purpose of the information exchange.
[5]
NOTE See the ISO 29481 series (information delivery manual, for BIM) and ISO 19109:2025 (General feature
model and rules for application schema, for GIS) for use-case driven modelling and methodologies.
5.2.2 Semantic-based concept linking
Concept matching shall be based primarily on semantic definitions, including the meaning, scope, and
constraints of concepts as defined in their respective source standards. Lexical similarity, such as identical
or similar names, shall not constitute sufficient evidence for establishing semantic equivalence. Where
lexical similarity contradicts semantic definitions, semantic definitions shall prevail. Additional supporting
elements, including semantic relationships, contextual constraints, and classification, shall be considered to
verify and validate cross-domain semantic alignment.
5.2.3 Appropriate standard reference
While data items are exchanged between BIM and GIS, the underlying conceptual schemas, data schemas
and schema languages shall be identified with reference to appropriate standards. The linkage of abstract

ISO/DIS 23143-3:2026(en)
concepts shall be documented with dated references and schema full version identification of schema
specifications. Where multiple standards could be referenced, the primary definitional source for the use
case shall be selected and recorded, while other sources may be cited informatively.
5.2.4 Domain symmetry
The linkage of abstract concepts shall be established on neutral basis between the BIM and GIS domains.
Neither domain shall be regarded as the dominant reference framework into which concepts from the
other domain are translated. Each linked schema element shall be identified, interpreted and documented
according to the standard in which it is formally defined. Domain symmetry applies to the method of linkage,
not to the resulting structures, i.e., differences in scope, granularity, directionality or loss may remain, but
they shall be recorded explicitly in the linkage.
5.2.5 Computer interpretability
Concept linkage shall be expressed in a computer-interpretable form to support automated processing,
formal validation and reusable deployment across software and databases systems. The representation
shall preserve identifiers, source standards, directionality, link type and any declared transformation or
loss. This document specifies an ontology-based, machine-interpretable representation of concept links that
may be adopted by either BIM or GIS implementations.
5.3 Framework
Both BIM and GIS contain a large number of abstract concepts, yet not all of which are involved in cross-
domain exchange; In particular, schema-internal syntactic constructs are designed mainly to build or
organize the schema rather than to convey exchange semantics.
To enable interoperability of the information defined by abstract concepts in international BIM and GIS
standards, concept links shall be established on the basis of shared domain cognition that concerns only the
definitions of exchange-relevant objects and their contextual specifications.
A set of five categories covers the exchange-relevant meaning of an object: basic context, object identification
and classification, geometric characteristics, attribute characteristics, and relationship structure.
The whole or part of the meaning for which an abstract concept is responsible shall correspond to one or
more of the five categories. On this basis, links between corresponding BIM and GIS abstract concepts can be
established, see Figure 2.
NOTE These five categories are further specified in Clause 7.

ISO/DIS 23143-3:2026(en)
Figure 2 — Framework of linking abstract concepts
5.4 Process for linking abstract concepts
The process for linking abstract concepts (see Figure 3) should be applied to all abstract concepts for defined
information exchange.
The process should consist of the following verifiable steps:
— Identify the candidate abstract concepts in BIM and GIS standards within the scope of the requirement.
— Identify which category or categories the abstract concepts correspond to.
— Compare the candidate abstract concepts to determine their semantic correspondence.
— Establish and document formalized representations of concept link.
Where no valid semantic relationship can be established without exceeding the defined scope or distorting
original semantics, the result shall be recorded as ‘Not applicable’ for the relevant use case.

ISO/DIS 23143-3:2026(en)
Figure 3 — Process for linking abstract concepts
5.5 Link types
The semantic relationship between linked abstract concepts in BIM and GIS shall be expressed using defined
link types. For this purpose, the link types specified in this subclause adopt SKOS (Simple Knowledge
Organization System) mapping properties to support recording degrees of semantic correspondence.

ISO/DIS 23143-3:2026(en)
The selection of a link type shall be based on the comparison described in Clause 8 and shall be explicitly
recorded in the concept link record.
The semantic relationship shall be expressed using the link types specified in Table 1.
NOTE SKOS is a W3C Recommendation. See W3C SKOS Reference for further details.
Table 1 — Link types
Link type Description
Indicates that two abstract concepts are fully semantically equivalent. Concepts
skos: exactMatch linked by this property can be used interchangeably across all contexts and use
case s, and the relation is transitive.
Indicates that two abstract concepts are highly similar but not fully equivalent.
skos: closeMatch They may differ slightly in scope, granularity, or usage, but are sufficiently similar
to be used interchangeably in most applications. This relation is not transitive.
Indicates that the target concept is semantically broader than the source concept.
skos: broadMatch The target concept encompasses the meaning of the source concept, providing a
more general or inclusive definition.
Indicates that the target concept is semantically narrower than the source con-
skos: narrowMatch cept. The target concept is a more specific or detailed instantiation of the source
concept.
Indicates an associative mapping link between two abstract concepts. This rela-
skos: relatedMatch
tion is symmetric.
6 Identification of abstract concepts
6.1 Sources
To support broad interoperability between BIM and GIS, this document draws on a set of widely adopted
international standards as the primary sources for identifying abstract concepts. Abstract concepts
identified under this document are traceable to explicit definitions in one or more of the following standards:
— BIM and GIS standards developed by ISO/TC 59/SC 13 and ISO TC 211;
— normative resources published by buildingSMART International (bSI) and the Open Geospatial
Consortium (OGC).
NOTE The standards listed is this subclause are selected because, together, they provide sufficient coverage of
the conceptual foundations shared across the two domains; the list is not intended to be exhaustive, nor to preclude
reference to other standards where appropriate.
6.2 Qualification of abstract concepts
Abstraction can be relative and context-dependent. The judgement of abstract concepts is constrained to the
defined use cases and information exchange requirements for BIM and GIS.
The following criteria shall be met to qualify abstract concepts for the linking process:
— The concept shall be semantically identifiable and uniquely distinguishable, with sufficiently
unambiguous definition to support reliable sematic linking.
— The concepts shall have a formal, normative definition in international standards and a standardized
schema representation; its identification shall be based on formal specification rather than conjecture
or implementation-specific artefacts.
— The semantic scope and normative definition of each abstract concept shall be strictly confined to its
originating standard, without unauthorised extension or redefinition during across-domain information
exchange.
ISO/DIS 23143-3:2026(en)
7 Identification of common categories for cross-domain exchange
7.1 General
This document defines five categories (see 5.3) to unify and classify abstract concepts derived from BIM and
GIS standards for cross-domain information exchange. These categories are domain-neutral and specified
as following common concepts (CC).
— Basic context (CC1), describing basic contextual settings within the defined scope of exchange, including
spatial reference system, temporal reference system, and measurement unit system.
— Object identification and classification (CC2), describing the unique identifier and semantic classification
and identity information of exchange-related objects.
— Geometric characteristics (CC3), describing the geometric representation and topological definition of
an exchange objects.
— Attribute characteristics (CC4), describing the properties reflecting the function, composition, and
structural feature of an exchange object, including item identifiers, descriptions, data types and
associated units.
— Relationship structure (CC5), describing semantic and spatial associations between an exchange objects
and other related objects.
NOTE These five categories are used not only to identify the abstract concepts addressed here, but also, in Clause
8 to provide the structure for establishing CLR-C and CLR-S, whereby one or more CLR-S support a CLR-C to enable
more precise links between abstract concepts in BIM and GIS.
EXAMPLE 1 Basic context (CC1): A coordinate reference system (e.g., EPSG: 4326) and a defined system of units (e.g.,
SI unit system) assigned to an exchange dataset establish the spatial datum and measurement basis for interpreting
all geometric and physical data within that dataset.
EXAMPLE 2 Object identification and classification (CC2): A permanent globally unique identifier (GUID) attached
to an object, together with standardized classification codes (e.g., OmniClass or Uniclass), enables cross-domain
traceability and consistent semantic recognition.
EXAMPLE 3 Geometric characteristics (CC3): The shape, extent, and spatial positioning of a building envelope,
represented as a Boundary Representation (B-Rep) solid with explicit local coordinates or converted to a GIS
multipolygon mesh.
EXAMPLE 4 Attribute characteristics (CC4): A specific property (e.g., "LoadCapacity") including its definition
reference, its data type (e.g., Real), its assigned value (e.g., 50.0), and its unit of measurement (e.g., tons) assigned to a
structural element.
EXAMPLE 5 Relationship structure (CC5): A spatial containment predicate indicating that a specific "Room" object
is contained within a "Storey" object, or an aggregation predicate indicating that a "Road" feature is composed of
multiple "RoadSegment" features.
For each category of common concepts, information may be exchanged with loss; however, it shall satisfy the
exchange requirements and reflect the intent of the information creator.
7.2 Basic Context (CC1)
7.2.1 General
The basic context shall underpin information exchange between BIM and GIS; all exchanges within the
agreed scope shall be consistent with CC1 as contextual specifications.
For large-area projects (e.g. long linear works), the capability to exchange information across zones shall
be considered. For projects crossing mountainous or undulating terrain, the adaptability of across-vertical-
datum shall be indicated.
ISO/DIS 23143-3:2026(en)
CC1 contextual information shall be managed and maintained as independent contextual metadata, It shall
not be merged or conflated with attribute information belonging to CC4 (see 6.5).
NOTE 1 CC1 establishes the spatiotemporal and measurement reference frameworks within which all exchange
objects exist; it provides the context for interpreting all subsequent geometric and attribute information. Class CC4
information, by contrast, comprises properties that describe the characteristics of individual exchange objects.
Conflating the two undermines the clarity of the data model.
Given that BIM–GIS information exchange is necessarily local in extent, this local extent should be treated as
a “project”.
NOTE 2 Although the notion of a “project” is relatively weak in GIS, it is the root object at the instance level that
governs contextual information for all systems and elements. In IFC, this root object is represented by the IfcProject
entity.
7.2.2 Spatial referencing
7.2.2.1 Coordinate reference system
A coordinate reference system (CRS) establishes the spatial datum (positioning datum) and the mode
of coordinate representation on which the geometric description of all spatial features is based; it is
a prerequisite for determining the spatial position of all engineering objects. In BIM–GIS information
exchange, CRS information shall be exchanged losslessly.
7.2.2.2 Spatial referencing by geographic identifier
This method locates features using geographic identifiers (e.g. place names, addresses) rather than
coordinates, relying on a gazetteer to establish the mapping between identifiers and coordinates (see
[9]
ISO 19112:2019 ). It facilitates human understanding and everyday use, and complements coordinate-
based reference systems.
7.2.3 Temporal referencing
Temporal referencing specifies the temporal basis on which exchange information is recorded and
interpreted. It shall specify consistent date, time notation and temporal reference system, to ensure unified
and unambiguous understanding of time-related information across the agreed exchange scope.
7.3 Object identity and classification (CC2)
7.3.1 General
Object identity provides the means to distinguish uniquely and persistently a specific object (e.g. a building or
bridge) within and across systems. It anchors the exchange object itself and provides a basis for subsequent
information
...