Geographic information — BIM to GIS conceptual mapping (B2GM)

This document defines the conceptual framework and mechanisms for mapping information elements from Building Information Modelling (BIM) to Geographic Information Systems (GIS) to access the required information based on specific user requirements. The conceptual framework for mapping BIM information to GIS is defined with the following three mapping mechanisms: — BIM to GIS Perspective Definition (B2G PD); — BIM to GIS Element Mapping (B2G EM); — BIM to GIS LOD Mapping (B2G LM). This document does not describe physical schema integration or mapping between BIM and GIS models because the physical schema integration or mapping between two heterogeneous models is very complex and can cause a variety of ambiguity problems. Developing a unified information model between BIM and GIS is a desirable goal, but it is out of the scope of this document. The scope of this document includes the following: — definition for BIM to GIS conceptual mapping requirement description; — definition of BIM to GIS conceptual mapping framework and component; — definition of mapping for export from one schema into another. The following concepts are outside the scope: — definition of any particular mapping application requirement and mechanism; — bi-directional mapping method between BIM and GIS; — definition of physical schema mapping between BIM and GIS; — definition of coordinate system mapping between BIM and GIS. NOTE For cases involving requirements related to Geo-referencing for providing the position and orientation of the BIM model based on GIS, there exist other standards such as ISO 19111 and the Information Delivery Manual (IDM) from buildingSMART on Geo-referencing BIM. — definition of relationship mapping between BIM and GIS; — implementation of the application schema.

Information géographique — Cartographique conceptuelle de BIM à GIS (B2GM)

General Information

Status
Published
Publication Date
13-May-2021
Current Stage
6060 - International Standard published
Start Date
14-May-2021
Due Date
01-Jul-2021
Completion Date
14-May-2021
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TECHNICAL ISO/TS
SPECIFICATION 19166
First edition
2021-05
Geographic information — BIM to GIS
conceptual mapping (B2GM)
Information géographique — Cartographique conceptuelle de BIM à
GIS (B2GM)
Reference number
ISO/TS 19166:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO/TS 19166:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/TS 19166:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abbreviated terms and notation . 4
4.1 Abbreviated terms . 4
4.2 UML Notation . 4
5 Conformance . 5
6 Conceptual Framework for BIM to GIS mapping . 5
6.1 General . 5
6.2 Conceptual overview . 5
6.3 Mechanisms . 6
7 BIM to GIS perspective definition . 9
7.1 General . 9
7.2 Mechanisms . 9
7.2.1 Data view . 9
7.2.2 Logic view .10
7.2.3 Style view .10
8 BIM to GIS element mapping .11
8.1 General .11
8.2 Mechanism .12
9 BIM to GIS LOD Mapping .13
9.1 General .13
9.2 Mechanism .14
Annex A (normative) Abstract test suite .16
Annex B (informative) B2G EM and LM example.18
Annex C (informative) Instance example using B2G PD .20
Annex D (informative) CityGML LOD model and mapping .21
Annex E (informative) LOD mapping rule description example .23
Bibliography .24
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ISO/TS 19166:2021(E)

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 of the voluntary nature of standards, 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 www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 211, Geographic information/Geomatics.
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.
iv © ISO 2021 – All rights reserved

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ISO/TS 19166:2021(E)

Introduction
Building Information Modelling (BIM) contains rich information related to building elements such as
doors, walls, windows, MEP (mechanical, electrical, and plumbing) and others. In addition, BIM models
may include information about other features than buildings, which are relevant to GIS. From the
viewpoint of GIS, there are many benefits related to using BIM information in GIS applications. Some
examples are:
a) Indoor service implementation such as emergency management (routing, evacuation path finding
under fire situation).
b) Outdoor - indoor linkage service, such as seamless navigation.
c) Effective facility/energy/environment management considering objects related BIM based on GIS.
Although there have been some attempts to harvest the rich information contained in BIM models and
use it in GIS, there is no established way to map the information elements between the two modelling
worlds. A proper mapping method is clearly required. Before the implementation of the information
mapping, however, mapping mechanisms for linking appropriate information elements from BIM to GIS
need to be clearly defined. In addition, for the mapping mechanisms to work together, a conceptual
framework for the mapping process based on open standards between BIM and GIS needs to be
established.
This document provides the conceptual framework for BIM to GIS information mapping and required
mapping mechanisms.
A brief explanation of each mapping mechanism follows:
— BIM to GIS Perspective Definition (B2G PD): supports perspective information representation
depending on the specific requirement such as the urban facility management (UFM). "Perspective"
depends on the use-case. For example, to manage the urban facilities, the required data should be
collected from the various data sources, including BIM model, and transformed to represent in
user-specific perspective. PD defines a Data View to extract the data required and transform the
information from the various data sources.
— BIM to GIS Element Mapping (B2G EM): supports the element mapping from BIM model to GIS model.
As the BIM and GIS model schemas are different, B2G EM requires a mapping rule specifying how to
transform from a BIM model to GIS model element.
— BIM to GIS LOD Mapping (B2G LM): supports the LOD mapping from BIM model to GIS model. LOD
(levels of detail) in GIS is a deliberate choice of data included/excluded from a model to satisfy
certain use cases including visualization. The relevant geometric and other information for the
LODs required in the target GIS model need to be extracted/or queried from the BIM model. This
can be defined by the LOD mapping ruleset.
This document is applicable to information query services such as urban facility management operation.
BIM object visualization in GIS and other application services that require query processing depending
on the relationship between BIM and GIS objects, either in the real or virtual world, will be able to
use the mechanisms defined in this document for mapping the required information elements between
the two systems. Although this document describes mapping information elements from BIM to GIS in
general, the primary concern of this document is mapping BIM models to GIS models for visualization.
The conceptual mapping mechanism defined in this document uses existing international standards
such as Geography Markup Language (GML) (ISO 19136-1) and Industry Foundation Classes (IFC)
(ISO 16739-1). The Open Geospatial Consortium (OGC)’s Land and Infrastructure Conceptual Model
Standard (LandInfra) (OGC 15-111r1) defines the information model of infrastructure such as roads. As
LandInfra has been designed with a common conceptual model between the BIM and GIS communities,
transferring information from LandInfra BIM models to LandInfra GIS models should be reasonably
straight forward. This document, therefore, concentrates on mapping from BIM models not based on
LandInfra.
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TECHNICAL SPECIFICATION ISO/TS 19166:2021(E)
Geographic information — BIM to GIS conceptual mapping
(B2GM)
1 Scope
This document defines the conceptual framework and mechanisms for mapping information elements
from Building Information Modelling (BIM) to Geographic Information Systems (GIS) to access the
required information based on specific user requirements.
The conceptual framework for mapping BIM information to GIS is defined with the following three
mapping mechanisms:
— BIM to GIS Perspective Definition (B2G PD);
— BIM to GIS Element Mapping (B2G EM);
— BIM to GIS LOD Mapping (B2G LM).
This document does not describe physical schema integration or mapping between BIM and GIS
models because the physical schema integration or mapping between two heterogeneous models is
very complex and can cause a variety of ambiguity problems. Developing a unified information model
between BIM and GIS is a desirable goal, but it is out of the scope of this document.
The scope of this document includes the following:
— definition for BIM to GIS conceptual mapping requirement description;
— definition of BIM to GIS conceptual mapping framework and component;
— definition of mapping for export from one schema into another.
The following concepts are outside the scope:
— definition of any particular mapping application requirement and mechanism;
— bi-directional mapping method between BIM and GIS;
— definition of physical schema mapping between BIM and GIS;
— definition of coordinate system mapping between BIM and GIS.
NOTE For cases involving requirements related to Geo-referencing for providing the position and orientation
of the BIM model based on GIS, there exist other standards such as ISO 19111 and the Information Delivery
Manual (IDM) from buildingSMART on Geo-referencing BIM.
— definition of relationship mapping between BIM and GIS;
— implementation of the application schema.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 19103, Geographic information — Conceptual schema language
ISO 19107, Geographic information — Spatial schema
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ISO/TS 19166:2021(E)

ISO 19109, Geographic information — Rules for application schema
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
application
manipulation and processing of data in support of user requirements
[SOURCE: ISO 19101-1:2014, 4.1.1]
3.2
application schema
conceptual schema for data required by one or more applications (3.1)
[SOURCE: ISO 19101-1:2014, 4.1.2]
3.3
class
description of a set of objects (3.9) that share the same attributes, operations, methods,
relationships and semantics
[SOURCE: ISO 19103:2015, 4.7, modified — domain has been added to the entry.]
3.4
complex feature
feature (3.6) composed of other features
[SOURCE: ISO 19109:2015, 4.3]
3.5
element
component including geometry, property, method, and relationship in a BIM or GIS model (3.8).
EXAMPLE In BIM, site, building, wall, door, and room are examples of elements, whereas in a GIS, site,
building, wall, room with infrastructure such as road, and bridge are examples of elements.
3.6
feature
abstraction of real-world phenomena
Note 1 to entry: A feature composed of other features is called a "complex feature" (3.4).
[SOURCE: ISO 19101-1:2014, 4.1.11, modified — Note 1 to entry modified.]
2 © ISO 2021 – All rights reserved

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ISO/TS 19166:2021(E)

3.7
level of detail
LOD
alternate representations of an object (3.9) at varying fidelities based on specific criteria
Note 1 to entry: The levels of detail concept of CityGML is widely accepted by the market and by the scientific
community. The term “LODX model” (X = {0, 1, 2, 3, 4}) is frequently used to address the complexity of existing
city models (3.8) and their suitability for specific applications (3.1). Buildings are represented by non-vertical
polygons, either at roof or at footprint level. In LOD1, volume objects such as buildings are modelled in a
generalized way as prismatic block models with vertical walls and horizontal ‘roofs’. In LOD2, the (prototypic)
roof shape of buildings is represented, as well as thematic ground, wall, and roof surfaces along with additional
structures such as balconies and dormers. LOD3 is the most detailed level for the outermost shape of objects.
For buildings, openings are added as thematic objects. In LOD4, interior structures (rooms, etc.) are added to the
most accurate outer representation, which is called LOD4 but almost identically to the LOD3 outer surface.
Note 2 to entry: It is important to note the distinction between the term LOD (levels of detail) in GIS usage and
the term LOD in BIM LOD (Level of Development). LOD in GIS is a deliberate choice of data included/excluded from
a model to satisfy certain use cases including visualization. LOD in BIM refers to the maturity of the planning
process of the real-world object modelled.
[SOURCE: ISO/IEC 18023-1:2006, 3.1.8, modified — Notes 1 and 2 to entry modified.]
3.8
model
abstraction of some aspects of reality
[SOURCE: ISO 19109:2015, 4.15]
3.9
object
object entity with a well-defined boundary and identity that encapsulates state and behaviour
[SOURCE: ISO 19103:2015, 4.25, modified — domain has been added to the entry.]
3.10
package
general purpose mechanism for organizing elements (3.5) into groups
[SOURCE: ISO 19103:2015, 4.27]
3.11
perspective
definition of the necessary data and behaviours for the use case context
Note 1 to entry: perspective in the construction industry in general, and construction modelling in particular, is
more like the common dictionary definition: “the art of representing three-dimensional objects (3.9) on a two-
dimensional surface so as to give the right impression of their height, width, depth and position in relation to
each other”.
Note 2 to entry: the use of ‘perspective’ in this document is similar to the BIM concept of ‘model view’, where ‘Model
View Definition’ is “A specification which identifies the properties and specifies the exchange requirements” – i.e.
what the customer wants/needs in the model (3.8) at that stage.
3.12
runtime
element (3.5) consisting of code and data produced by the compilation of a source element
[SOURCE: ISO/IEC 1989:2014, 4.168, modified.]
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ISO/TS 19166:2021(E)

3.13
system
applications (3.1), services, information technology assets, or other information handling components
[SOURCE: ISO/IEC 29134:2017, 3.13]
3.14
system property
customized system (3.13) settings used when automatically creating a model
EXAMPLE GUID
4 Abbreviated terms and notation
4.1 Abbreviated terms
B2G EM BIM to GIS element mapping
B2G LM BIM to GIS LOD mapping
B2G PD BIM to GIS perspective definition
B2G CM BIM to GIS conceptual mapping
BIM Building Information Modelling
BIM model Building Information Model
B-rep boundary representation
ETL Extract/Transform/Load
FM facility management
FK foreign key
GIS Geographic Information System
GIS model Geographic Information System Model
GUID Globally Unique Identifier
OBB oriented bounding box
PD perspective definition
PK primary key
PSet property set
UML Unified Modelling Language
URI Uniform Resource Identifier
XML Extensible Markup Language
4.2 UML Notation
In this document, conceptual schemas are presented in the Unified Modelling Language (UML). The
user shall refer to ISO 19103 for the specific profile of UML used in this document.
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ISO/TS 19166:2021(E)

5 Conformance
This document defines the requirements classes in Clauses 7, 8, and 9.
6 Conceptual Framework for BIM to GIS mapping
6.1 General
The BIM to GIS conceptual mapping (B2G CM) is the conceptual framework for object mapping from
a BIM model to a GIS model which includes the transform ruleset related to class elements, LODs, and
geometries.
B2G CM considers the following:
— The way for users to design, predict and check the results of model integration explicitly.
— The way for users to define, connect and integrate the data they need from a user perspective.
— The way for users to exclude unnecessary data and determine the amount of data needed.
6.2 Conceptual overview
Figure 1 presents a conceptual overview of B2G CM as defined in this document and presents the
relationship of the mapping mechanisms.
— Perspective definition for data view. Perspective information representation depending on the
specific use-cases such as user facility management. "Perspective" is dependent on the use-case to
extract the needed data. PD consists of three mechanisms to extract the external data needed.
— Element mapping from BIM to GIS model. To transform the elements from the BIM model to the
GIS model, it is necessary to define the element mapping mechanism that transforms the BIM to
GIS model elements. Element Mapping describes the mapping requirement definition related to the
element mapping mechanism from the viewpoint of specific use cases.
— LOD definition and mapping from BIM model to GIS model. The LOD models define a visualization
mechanism. However, there is no LOD schema in BIM objects defined in the BIM model, ISO 16739.
To represent BIM geometry in a GIS, LOD information can need to be extracted from the BIM model.
Figure 1 — B2G CM Conceptual Overview
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ISO/TS 19166:2021(E)

6.3 Mechanisms
Using the mapping framework defined in this document, it is possible to query the information from the
linked database that utilizes the BIM information. Figure 2 shows use cases of querying information
from an integrated database that includes both GIS and BIM information elements.
Figure 2 — Link database and integrated query based on B2G CM use cases
B2G CM supports BIM model-to-GIS model mapping under the BIM and GIS model requirement scope
in Table 1. The geometry of the BIM and GIS models should be able to define the B-rep by referring to
ISO 19109 GFM (general feature model) and ISO 19107 spatial schema, as shown in Figure 3.
Figure 3 — BIM and GIS model requirement
The minimum information requirements for BIM model-to-GIS model mapping by model package are
defined in Table 1.
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ISO/TS 19166:2021(E)

Table 1 — Package Requirements
Package Requirements
BIM model A BIM model shall define the following object information.
BM1. BIM_element: capability to define the runtime of construction components, geometry,
property, and relationship.
BM2. runtime: capability to identify the types of BIM element. The types are building in-
formation components such as walls, doors, and rooms.
BM3. geometry: capability to contain the solid information including B-rep (boundary
representation) based on GM_Solid. The B-rep information must include the topology such
as the vertex, edge, loop and faces.
BM4. property_set: capability to categorize the attributes of the BIM elements and to define
the {name, value type, initial value} pairs.
In addition, the system properties of the property information shall be defined. The system
properties are automatically created when creating a BIM model. The system properties
are the BIM element name and the GUID.
BM5(Optional). relationship: capability to contain the relationships between the BIM ele-
ments. The relationships follow the UML relationships. The relationships covered in this
document are Association, Dependency, and Generalization.
GIS model A GIS model shall define the following object information.
GM1. GIS_element: capability to define the runtime, geometry, property and relationship,
which are the GIS model components.
GM2. runtime: capability to identify the types of GIS element. The types include the site,
building and room, which are the same architectural information components.
GM3. geometry: capability to contain the LOD and Solid information based on GM_solid.
The B-rep information shall include the topology such as the vertex, edge, loop and faces.
GM4. property_set: capability to categorize the attributes of the GIS element and to define
the {name, value type, initial value} pairs.
In addition, the system properties of the property information shall be defined. The system
properties are automatically created when creating a GIS model. The system properties are
the GIS element name.
GM5(Optional). capability to contain the relationships between the GIS elements. The re-
lationships follow the UML relationships. The relationships covered in this document are
Association, Dependency, and Generalization.
The BIM model class structures reflecting the requirements defined in Table 1 can be expressed in UML
as shown in Figure 4.
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ISO/TS 19166:2021(E)

Figure 4 — BIM model conceptual diagram in UML
Similarly, the GIS model class structures reflecting the requirements defined in Table 1 can also be
expressed in UML as shown in Figure 5.
Figure 5 — GIS model conceptual diagram in UML
Package relationships for the B2G CM are shown in Figure 6.
Figure 6 — B2G CM package relationships in UML
To perform the mapping function each package shall meet the requirements specified in Table 2.
8 © ISO 2021 – All rights reserved

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ISO/TS 19166:2021(E)

Table 2 — B2G CM package requirements
Package Requirements
B2G PD External data associations and views that require BIM from a use case perspective
shall be supported. The external data required for B2G CM shall be capable of being
uniquely linked to the PK (primary key), such as the BIM element GUID.
The data view shall define an external data item to link to the BIM model element.
The value of the associated data item shall enable change into a format that can be
used in the use case.
A more detailed definition of this operator is defined in Clause 7.
B2G EM The following mapping operators shall be defined for element mapping. Predefined
operators can be used to create mapping rules. The mapping rules can be configured
differently depending on the use case.
EM()EE→
BG
Where
   E is an element of BIM
B
   E is an element of GIS
G
A more detailed definition of this operator is defined in Clause 8.
B2G LM The following mapping operator shall be defined for LOD mapping.
LM(,LL→ LOD )
BG name
Where
   L          is the LOD of BIM
B
   L          is the LOD of GIS
G
   LOD    is the name of LOD
name
A more detailed definition of this operator is defined in Clause 9.
7 BIM to GIS perspective definition
7.1 General
B2G PD supports the method for perspective information representation depending on the specific use
cases. To define the information perspective for binding and using BIM, GIS and external data sets, B2G
PD includes the methods specifying:
— what data is needed related to BIM model use cases,
— how to extract and integrate the data between BIM, GIS and external data sets, and
— how to represent the integrated information.
7.2 Mechanisms
The methods listed in 7.1 have been divided into stages of information processing such as DataView
(7.2.1) according to perspect
...

TECHNICAL ISO/TS
SPECIFICATION 19166
First edition
Geographic information — BIM to GIS
conceptual mapping (B2GM)
Information géographique — Cartographique conceptuelle de BIM à
GIS (B2GM)
PROOF/ÉPREUVE
Reference number
ISO/TS 19166:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO/TS 19166:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii PROOF/ÉPREUVE © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/TS 19166:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abbreviated terms and notation . 4
4.1 Abbreviated terms . 4
4.2 UML Notation . 4
5 Conformance . 5
6 Conceptual Framework for BIM to GIS mapping . 5
6.1 General . 5
6.2 Conceptual overview . 5
6.3 Mechanisms . 6
7 BIM to GIS perspective definition .10
7.1 General .10
7.2 Mechanisms .10
7.2.1 Data view .10
7.2.2 Logic view .10
7.2.3 Style view .10
8 BIM to GIS element mapping .12
8.1 General .12
8.2 Mechanism .12
9 BIM to GIS LOD Mapping .13
9.1 General .13
9.2 Mechanism .14
Annex A (normative) Abstract test suite .16
Annex B (informative) B2G EM and LM example.18
Annex C (informative) Instance example using B2G PD .20
Annex D (informative) CityGML LOD model and mapping .21
Annex E (informative) LOD mapping rule description example .23
Bibliography .24
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ISO/TS 19166:2021(E)

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 of the voluntary nature of standards, 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 www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 211, Geographic information/Geomatics.
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.
iv PROOF/ÉPREUVE © ISO 2021 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/TS 19166:2021(E)

Introduction
Building Information Modelling (BIM) contains rich information related to building elements such as
doors, walls, windows, MEP (mechanical, electrical, and plumbing) and others. In addition, BIM models
may include information about other features than buildings, which are relevant to GIS. From the
viewpoint of GIS, there are many benefits related to using BIM information in GIS applications. Some
examples are:
a) Indoor service implementation such as emergency management (routing, evacuation path finding
under fire situation);
b) Outdoor - indoor linkage service, such as seamless navigation.
c) Effective facility/energy/environment management considering objects related BIM based on GIS.
Although there have been some attempts to harvest the rich information contained in BIM models and
use it in GIS, there is no established way to map the information elements between the two modelling
worlds. A proper mapping method is clearly required. Before the implementation of the information
mapping, however, mapping mechanisms for linking appropriate information elements from BIM to GIS
need to be clearly defined. In addition, for the mapping mechanisms to work together, a conceptual
framework for the mapping process based on open standards between BIM and GIS needs to be
established.
This document provides the conceptual framework for BIM to GIS information mapping and required
mapping mechanisms.
A brief explanation of each mapping mechanism follows:
— BIM to GIS Perspective Definition (B2G PD): supports perspective information representation
depending on the specific requirement such as the urban facility management (UFM). "Perspective"
depends on the use-case. For example, to manage the urban facilities, the required data should be
collected from the various data sources, including BIM model, and transformed to represent in
user-specific perspective. PD defines a Data View to extract the data required and transform the
information from the various data sources.
— BIM to GIS Element Mapping (B2G EM): supports the element mapping from BIM model to GIS model.
As the BIM and GIS model schemas are different, B2G EM requires a mapping rule specifying how to
transform from a BIM model to GIS model element.
— BIM to GIS LOD Mapping (B2G LM): supports the LOD mapping from BIM model to GIS model. LOD
(levels of detail) in GIS is a deliberate choice of data included/excluded from a model to satisfy
certain use cases including visualization. The relevant geometric and other information for the
LODs required in the target GIS model need to be extracted/or queried from the BIM model. This
can be defined by the LOD mapping ruleset.
This document is applicable to information query services such as urban facility management operation.
BIM object visualization in GIS and other application services that require query processing depending
on the relationship between BIM and GIS objects, either in the real or virtual world, will be able to
use the mechanisms defined in this document for mapping the required information elements between
the two systems. Although this document describes mapping information elements from BIM to GIS in
general, the primary concern of this document is mapping BIM models to GIS models for visualization.
The conceptual mapping mechanism defined in this document uses existing international standards
such as Geography Markup Language (GML) (ISO 19136-1) and Industry Foundation Classes (IFC)
(ISO 16739-1). The Open Geospatial Consortium (OGC)’s Land and Infrastructure Conceptual Model
Standard (LandInfra) (OGC 15-111r1) defines the information model of infrastructure such as roads. As
LandInfra has been designed with a common conceptual model between the BIM and GIS communities,
transferring information from LandInfra BIM models to LandInfra GIS models should be reasonably
straight forward. This document, therefore, concentrates on mapping from BIM models not based on
LandInfra.
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TECHNICAL SPECIFICATION ISO/TS 19166:2021(E)
Geographic information — BIM to GIS conceptual
mapping (B2GM)
1 Scope
This document defines the conceptual framework and mechanisms for mapping information elements
from Building Information Modelling (BIM) to Geographic Information Systems (GIS) to access the
required information based on specific user requirements.
The conceptual framework for mapping BIM information to GIS is defined with the following three
mapping mechanisms:
— BIM to GIS Perspective Definition (B2G PD);
— BIM to GIS Element Mapping (B2G EM);
— BIM to GIS LOD Mapping (B2G LM);
This document does not describe physical schema integration or mapping between BIM and GIS
models because the physical schema integration or mapping between two heterogeneous models is
very complex and can cause a variety of ambiguity problems. Developing a unified information model
between BIM and GIS is a desirable goal, but it is out of the scope of this document.
The scope of this document includes the following:
— definition for BIM to GIS conceptual mapping requirement description;
— definition of BIM to GIS conceptual mapping framework and component.
— definition of mapping for export from one schema into another.
The following concepts are outside the scope:
— definition of any particular mapping application requirement and mechanism;
— bi-directional mapping method between BIM and GIS;
— definition of physical schema mapping between BIM and GIS;
— definition of coordinate system mapping between BIM and GIS;
NOTE For cases involving requirements related to Geo-referencing for providing the position and orientation
of the BIM model based on GIS, there exist other standards such as ISO 19111 and the Information Delivery
Manual (IDM) from buildingSMART on Geo-referencing BIM.
— definition of relationship mapping between BIM and GIS;
— implementation of the application schema.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 19103, Geographic information — Conceptual schema language
ISO 19107, Geographic information — Spatial schema
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ISO 19109, Geographic information — Rules for application schema
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
application
manipulation and processing of data in support of user requirements
[SOURCE: ISO 19101-1:2014, 4.1.1]
3.2
application schema
conceptual schema for data required by one or more applications (3.1)
[SOURCE: ISO 19101-1:2014, 4.1.2]
3.3
class
description of a set of objects (3.9) that share the same attributes, operations, methods,
relationships and semantics
[SOURCE: ISO 19103:2015, 4.7, modified — domain has been added to the entry.]
3.4
complex feature
feature (3.6) composed of other features
[SOURCE: ISO 19109:2015, 4.3]
3.5
element
component including geometry, property, method, and relationship in a BIM or GIS model (3.8).
EXAMPLE In BIM, site, building, wall, door, and room are examples of elements, whereas in a GIS, site,
building, wall, room with infrastructure such as road, and bridge are examples of elements.
3.6
feature
abstraction of real-world phenomenaNote 1 to entry: A feature composed of other features is called a
"complex feature" (3.4).
[SOURCE: ISO 19101-1:2014, 4.1.11, modified — Note 1 to entry modified.]
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3.7
level of detail
LOD
alternate representations of an object (3.9) at varying fidelities based on specific criteria
Note 1 to entry: The levels of detail concept of CityGML is widely accepted by the market and by the scientific
community. The term “LODX model” (X = {0, 1, 2, 3, 4}) is frequently used to address the complexity of existing
city models (3.8) and their suitability for specific applications (3.1). Buildings are represented by non-vertical
polygons, either at roof or at footprint level. In LOD1, volume objects such as buildings are modelled in a
generalized way as prismatic block models with vertical walls and horizontal ‘roofs’. In LOD2, the (prototypic)
roof shape of buildings is represented, as well as thematic ground, wall, and roof surfaces along with additional
structures such as balconies and dormers. LOD3 is the most detailed level for the outermost shape of objects.
For buildings, openings are added as thematic objects. In LOD4, interior structures (rooms, etc.) are added to the
most accurate outer representation, which is called LOD4 but almost identically to the LOD3 outer surface.
Note 2 to entry: It is important to note the distinction between the term LOD (levels of detail) in GIS usage and
the term LOD in BIM LOD (Level of Development). LOD in GIS is a deliberate choice of data included/excluded from
a model to satisfy certain use cases including visualization. LOD in BIM refers to the maturity of the planning
process of the real-world object modelled.
[SOURCE: ISO/IEC 18023-1:2006, 3.1.8, modified — Notes 1 and 2 to entry modified.]
3.8
model
abstraction of some aspects of reality
[SOURCE: ISO 19109:2015, 4.15]
3.9
object
object entity with a well-defined boundary and identity that encapsulates state and behaviour
[SOURCE: ISO 19103:2015, 4.25, modified — domain has been added to the entry.]
3.10
package
general purpose mechanism for organizing elements (3.5) into groups
[SOURCE: ISO 19103:2015, 4.27]
3.11
perspective
definition of the necessary data and behaviours for the use case context
Note 1 to entry: perspective in the construction industry in general, and construction modelling in particular, is
more like the common dictionary definition: “the art of representing three-dimensional objects (3.9) on a two-
dimensional surface so as to give the right impression of their height, width, depth and position in relation to
each other”.
Note 2 to entry: the use of ‘perspective’ in this document is similar to the BIM concept of ‘model view’, where ‘Model
View Definition’ is “A specification which identifies the properties and specifies the exchange requirements” – i.e.
what the customer wants/needs in the model (3.8) at that stage.
3.12
runtime
element (3.5) consisting of code and data produced by the compilation of a source element
[SOURCE: ISO/IEC 1989:2014, 4.168, modified.]
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3.13
system
applications (3.1), services, information technology assets, or other information handling components
[SOURCE: ISO/IEC 29134:2017, 3.13]
3.14
system property
customized system (3.13) settings used when automatically creating a model
EXAMPLE GUID
4 Abbreviated terms and notation
4.1 Abbreviated terms
B2G EM BIM to GIS element mapping
B2G LM BIM to GIS LOD mapping
B2G PD BIM to GIS perspective definition
B2G CM BIM to GIS conceptual mapping
BIM Building Information Modelling
BIM model Building Information Model
B-rep boundary representation
ETL Extract/Transform/Load
FM facility management
FK foreign key
GIS Geographic Information System
GIS model Geographic Information System Model
GUID Globally Unique Identifier
OBB oriented bounding box
PD perspective definition
PK primary key
PSet property set
UML Unified Modelling Language
URI Uniform Resource Identifier
XML Extensible Markup Language
4.2 UML Notation
In this document, conceptual schemas are presented in the Unified Modelling Language (UML). The
user shall refer to ISO 19103 for the specific profile of UML used in this document.
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5 Conformance
This document defines the requirements classes in Clauses 7, 8, and 9.
6 Conceptual Framework for BIM to GIS mapping
6.1 General
The BIM to GIS conceptual mapping (B2G CM) is the conceptual framework for object mapping from
a BIM model to a GIS model which includes the transform ruleset related to class elements, LODs, and
geometries.
B2G CM considers the following:
— The way for users to design, predict and check the results of model integration explicitly.
— The way for users to define, connect and integrate the data they need from a user perspective.
— The way for users to exclude unnecessary data and determine the amount of data needed.
6.2 Conceptual overview
Figure 1 presents a conceptual overview of B2G CM as defined in this document and presents the
relationship of the mapping mechanisms.
— Perspective definition for data view. Perspective information representation depending on the
specific use-cases such as user facility management. "Perspective" is dependent on the use-case to
extract the needed data. PD consists of three mechanisms to extract the external data needed.
— Element mapping from BIM to GIS model. To transform the elements from the BIM model to the
GIS model, it is necessary to define the element mapping mechanism that transforms the BIM to
GIS model elements. Element Mapping describes the mapping requirement definition related to the
element mapping mechanism from the viewpoint of specific use cases.
— LOD definition and mapping from BIM model to GIS model. The LOD models define a visualization
mechanism. However, there is no LOD schema in BIM objects defined in the BIM model, ISO 16739.
To represent BIM geometry in a GIS, LOD information can need to be extracted from the BIM model.
Figure 1 — B2G CM Conceptual Overview
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6.3 Mechanisms
Using the mapping framework defined in this document, it is possible to query the information from the
linked database that utilizes the BIM information. Figure 2 shows use cases of querying information
from an integrated database that includes both GIS and BIM information elements.
Figure 2 — Link database and integrated query based on B2G CM use cases
B2G CM supports BIM model-to-GIS model mapping under the BIM and GIS model requirement scope
in Table 1. The geometry of the BIM and GIS models should be able to define the B-rep by referring to
ISO 19109 GFM (general feature model) and ISO 19107 spatial schema, as shown in Figure 3.
Figure 3 — BIM and GIS model requirement
The minimum information requirements for BIM model-to-GIS model mapping by model package are
defined in Table 1.
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ISO/TS 19166:2021(E)

Table 1 — Package Requirements
Package Requirements
BIM model A BIM model shall define the following object information.
BM1. BIM_element: capability to define the runtime of construction components, geometry,
property, and relationship.
BM2. runtime: capability to identify the types of BIM element. The types are building in-
formation components such as walls, doors, and rooms.
BM3. geometry: capability to contain the solid information including B-rep (boundary
representation) based on GM_Solid. The B-rep information must include the topology such
as the vertex, edge, loop and faces.
BM4. property_set: capability to categorize the attributes of the BIM elements and to define
the {name, value type, initial value} pairs.
In addition, the system properties of the property information shall be defined. The system
properties are automatically created when creating a BIM model. The system properties
are the BIM element name and the GUID.
BM5(Optional). relationship: capability to contain the relationships between the BIM ele-
ments. The relationships follow the UML relationships. The relationships covered in this
document are Association, Dependency, and Generalization.
GIS model A GIS model shall define the following object information.
GM1. GIS_element: capability to define the runtime, geometry, property and relationship,
which are the GIS model components.
GM2. runtime: capability to identify the types of GIS element. The types include the site,
building and room, which are the same architectural information components.
GM3. geometry: capability to contain the LOD and Solid information based on GM_solid.
The B-rep information shall include the topology such as the vertex, edge, loop and faces.
GM4. property_set: capability to categorize the attributes of the GIS element and to define
the {name, value type, initial value} pairs.
In addition, the system properties of the property information shall be defined. The system
properties are automatically created when creating a GIS model. The system properties are
the GIS element name.
GM5(Optional). capability to contain the relationships between the GIS elements. The re-
lationships follow the UML relationships. The relationships covered in this document are
Association, Dependency, and Generalization.
The BIM model class structures reflecting the requirements defined in Table 1 can be expressed in UML
as shown in Figure 4.
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Figure 4 — BIM model conceptual diagram in UML
Similarly, the GIS model class structures reflecting the requirements defined in Table 1 can also be
expressed in UML as shown in Figure 5.
Figure 5 — GIS model conceptual diagram in UML
Package relationships for the B2G CM are shown in Figure 6.
Figure 6 — B2G CM package relationships in UML
To perform the mapping function each package shall meet the requirements specified in Table 2.
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Table 2 — B2G CM package requirements
Package Requirements
B2G PD External data associations and views that require BIM from a use case perspective
shall be supported. The external data required for B2G CM shall be capable of being
uniquely linked to the PK (primary key), such as the BIM element GUID.
The data view shall define an external data item to link to the BIM model element.
The value of the associated data item shall enable change into a format that can be
used in the use case.
A more detailed definition of this operator is defined in Clause 7.
B2G EM The following mapping operators shall be defined for element mapping. Predefined
operators can be used to create mapping rules. The mapping rules can be configured
differently depending on the use case.
EM()EE→
BG
where

E
B
is an element of BIM

E
G
is an element of GIS
A more detailed definition of this operator is defined in Clause 8.
B2G LM The following mapping operator shall be defined for LOD mapping.
LM(,LL→ LOD )
BG name
where

L
B
is the LOD of BIM

L
G
is the LOD of GIS

LOD
name
name of LOD
A more detailed definition of this operator is defined in Clause 9.
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7 BIM to GIS perspective definition
7.1 General
B2G PD supports the method for perspective information representation depending on the specific use
cases. To define the information perspective for binding and using BIM, GIS and external data sets, B2G
PD includes the methods specifying:
— what data is needed related to BIM model use cases,
— how to extract and integrate the data between BIM, GIS and external data sets, and
— how
...

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