SIST EN ISO 16757-5:2026
(Main)Data structures for electronic product catalogues for building services - Part 5: Product catalogue exchange format (ISO 16757-5:2025)
Data structures for electronic product catalogues for building services - Part 5: Product catalogue exchange format (ISO 16757-5:2025)
This document describes how product catalogue data for building services products is exchanged by means of ISO 16739-1 (Industry Foundation Classes, IFC) and EN 17549-2 from manufacturers to designers of building services systems.
This document specifies how the product catalogue structures and content are set up using the definitions stored in a data dictionary.
In scope of this document are:
— processes for the provision and exchange of product catalogues;
— rules for the geometrical representation of products;
— representation of products, product classes, ports, in/outlets, components and accessories by using IFC;
— representation of properties in IFC and the use of IFC constraints for the representation of product variants;
— representation of parametric geometry and the generation of IFC geometries for selected variants;
— calculation of article number.
The resulting product catalogue can be used by designers to select the desired products and integrate them into their model of the building services system.
The expected audience of this document are software providers for the built environment sector and professionals working in the sector who create product catalogues or use product catalogues by means of software tools.
Not in scope of this document is the representation of properties in data dictionaries. The use of data dictionaries is described in ISO 16757-4.
Datenstrukturen für elektronische Produktkataloge der Technischen Gebäudeausrüstung - Teil 5: Austauschformat für Produktkataloge (ISO 16757-5:2025)
Dieses Dokument beschreibt, wie Produktkatalogdaten für Gebäudeausrüstungsprodukte anhand von ISO 16739 1 (Industry Foundation Classes, IFC) und EN 17549 2 von Herstellern an Planer von Gebäudeausrüstungssystemen ausgetauscht werden.
Dieses Dokument legt fest, wie die Strukturen und Inhalte des Produktkatalogs anhand der in einem Datenkatalog gespeicherten Definitionen erstellt werden.
Im Anwendungsbereich dieses Dokuments sind:
Prozesse für die Bereitstellung und den Austausch von Produktkatalogen;
Regeln für die geometrische Darstellung von Produkten;
Darstellung von Produkten, Produktklassen, Anschlüssen, Ein-/Ausgängen, Komponenten und Zubehör durch die Verwendung von IFC;
Darstellung von Merkmalen in IFC und die Verwendung von IFC Einschränkungen für die Darstellung von Produktvarianten;
Darstellung der parametrischen Geometrie und die Erzeugung von IFC Geometrien für ausgewählte Varianten;
Berechnung der Artikelnummer.
Der sich daraus ergebende Produktkatalog kann von Planern verwendet werden, um die gewünschten Produkte auszuwählen und sie in ihr Modell des technischen Gebäudeausrüstungssystems zu integrieren.
Dieses Dokument richtet sich an Anbieter von Software für die gebaute Umwelt und an Fachleute in diesem Bereich, die Produktkataloge erstellen oder Produktkataloge mithilfe von Softwaretools verwenden.
Nicht im Anwendungsbereich dieses Dokuments ist die Darstellung von Merkmalen in Datenkatalogen. Die Verwendung von Datenkatalogen wird in ISO 16757 4 beschrieben.
Structures de données pour catalogues électroniques de produits pour les services du bâtiment - Partie 5: Format d'échange pour les catalogues de produits (ISO 16757-5:2025)
Le présent document décrit la façon dont les données du catalogue de produits pour les produits des services du bâtiment sont échangées au moyen de l’ISO 16739-1 (classes de fondation d’industrie, IFC) et de l’EN 17549-2 entre les fabricants et les concepteurs de systèmes de services du bâtiment.
Le présent document spécifie la manière dont les structures et le contenu du catalogue de produits sont définis en utilisant les définitions stockées dans un dictionnaire de données.
Sont inclus dans le domaine d’application du présent document:
— les processus de fourniture et d’échange de catalogues de produits;
— les règles de représentation géométrique des produits;
— la représentation des produits, classes de produits, interfaces, entrées/sorties, composants et accessoires en utilisant les IFC;
— la représentation des propriétés en IFC et l’utilisation des contraintes IFC pour la représentation des variantes de produits;
— la représentation de la géométrie paramétrique et la génération de géométries IFC pour les variantes sélectionnées;
— le calcul du nombre d’articles.
Les concepteurs peuvent utiliser le catalogue de produits résultant pour sélectionner les produits souhaités et les intégrer dans leur modèle du système de services du bâtiment.
Le présent document est destiné aux fournisseurs de logiciels dans le secteur de l’environnement bâti, ainsi qu’aux professionnels travaillant dans ce secteur qui créent ou utilisent des catalogues de produits au moyen d’outils logiciels.
Le domaine d’application du présent document ne couvre pas la représentation des propriétés dans les dictionnaires de données. L’utilisation des dictionnaires de données est décrite dans l’ISO 16757-4.
Podatkovne strukture digitalnih knjižnic gradnikov stavbnih sistemov - 5. del: Format izmenjave za kataloge izdelkov (ISO 16757-5:2025)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2026
Podatkovne strukture digitalnih knjižnic gradnikov stavbnih sistemov - 5. del:
Format izmenjave za kataloge izdelkov (ISO 16757-5:2025)
Data structures for electronic product catalogues for building services - Part 5: Product
catalogue exchange format (ISO 16757-5:2025)
Datenstrukturen für elektronische Produktkataloge der Technischen Gebäudeausrüstung
- Teil 5: Austauschformat für Produktkataloge (ISO 16757-5:2025)
Structures de données pour catalogues électroniques de produits pour les services du
bâtiment - Partie 5: Format d'échange pour les catalogues de produits (ISO 16757-
5:2025)
Ta slovenski standard je istoveten z: EN ISO 16757-5:2025
ICS:
35.240.67 Uporabniške rešitve IT v IT applications in building
gradbeništvu and construction industry
91.010.01 Gradbeništvo na splošno Construction industry in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 16757-5
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2025
EUROPÄISCHE NORM
ICS 91.010.01
English Version
Data structures for electronic product catalogues for
building services - Part 5: Product catalogue exchange
format (ISO 16757-5:2025)
Structures de données pour catalogues électroniques Datenstrukturen für elektronische Produktkataloge
de produits pour les services du bâtiment - Partie 5: der Technischen Gebäudeausrüstung - Teil 5:
Format d'échange des catalogues de produits (ISO Austauschformat für Produktkataloge (ISO 16757-
16757-5:2025) 5:2025)
This European Standard was approved by CEN on 29 September 2025.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16757-5:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 16757-5:2025) has been prepared by Technical Committee ISO/TC 59
"Buildings and civil engineering works" in collaboration with Technical Committee CEN/TC 442
“Building Information Modelling (BIM)” the secretariat of which is held by SN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2026, and conflicting national standards shall be
withdrawn at the latest by April 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 16757-5:2025 has been approved by CEN as EN ISO 16757-5:2025 without any
modification.
International
Standard
ISO 16757-5
First edition
Data structures for electronic
2025-10
product catalogues for building
services —
Part 5:
Product catalogue exchange format
Structures de données pour catalogues électroniques de produits
pour les services du bâtiment —
Partie 5: Format d’échange des catalogues de produits
Reference number
ISO 16757-5:2025(en) © ISO 2025
ISO 16757-5:2025(en)
© ISO 2025
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
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 16757-5:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Overview of supported processes . 2
4.1 General .2
4.2 Creation of product catalogues using the definitions in the data dictionary .3
4.3 Provision of the product catalogue .4
4.4 Product determination in the product catalogue .4
4.5 Product integration into the technical system model .4
4.6 Data exchange of the technical system model .5
4.7 Use of product catalogues according to the ISO 16757 series .5
5 Product representation . 5
5.1 Part numbers .5
5.2 Geometry .5
5.3 Symbolic geometry .8
5.4 Shape geometry .8
5.5 Ports .10
5.6 In/outlets .10
5.7 Spaces . 12
5.8 Media data . 12
6 Product catalogue as IFC structure .13
6.1 General . 13
6.2 IFC catalogue metadata .14
6.3 Product classes and their structures in IFC .14
6.4 Product series in IFC .16
6.5 Components and accessories in IFC .16
6.6 Properties and constraints for property values in IFC .17
6.7 Parametric geometry in IFC . 20
6.8 Product ports in IFC .21
6.9 Product in/outlets in IFC . 22
6.10 Part numbers in IFC tables or created by scripts . 23
6.11 External media data .24
7 Centrally stored property data dictionary .24
8 JavaScript (ECMA script) functions .24
Annex A (informative) Data structure examples .25
Annex B (informative) Example: product selection programme, procedure .32
Annex C (informative) Example: IFC file with IFC meta-object geometry .33
Annex D (informative) Example: Pseudo IFC file as meta geometry with variable dimension
terms (reduced) .39
Annex E (informative) Example: spreadsheet as meta geometry .53
Annex F (informative) Example: silencer referencing an external document. 67
Annex G (informative) Example: silencer with properties and various types of constraints .70
Bibliography .89
iii
ISO 16757-5:2025(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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 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), in collaboration with the European Committee
for Standardization (CEN) Technical Committee CEN/TC 442, Building Information Modelling (BIM), in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 16757 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.
iv
ISO 16757-5:2025(en)
Introduction
Building information modelling (BIM) provides a means for describing and displaying information required
throughout the asset life cycle. Increasingly this modelling approach is expanding to encompass all aspects
of the built environment, including civil infrastructure, utilities and public space.
The ISO 16757 series provides the structure of a product catalogue model for data sharing and data exchange
of product models in product catalogues. It contains specifications for:
— selection of products from different product classes and product variants;
— combining product components and accessories to products;
— geometrical representation in technical systems;
— connectivity to other products in models of technical systems;
— calculation of dynamic property values in accordance with the product behaviour in technical systems.
Specialist planners of complete systems for building services, for example, expect almost all of this data in
the product catalogue, as they require the shape data for dimensioning and clash detection in addition to the
technical design and setting of the products.
This data format provides the opportunity to search and select product data together with accessory data
which can be read into software applications for planning, designing, calculating and simulating as well as
for facility managing.
This document focuses only on the format of the data exchanged and not on how to process it. Notes on the
implementation of the standard in application software can be found in Annex B.
This document does not directly lead to an automatic selection of products.
The product catalogue does not contain any decision criteria for this. However, the data of a product
catalogue can be searched by application programs looking for a suitable product size.
According to ISO 16757-4, this document does not provide a data template, as it assumes that these are
already defined in data dictionaries according to ISO 12006-3.
Besides this document, the ISO 16757 series contains the following documents:
— ISO 16757-1 describes the fundamental concepts and assumptions about the creation of manufacturer-
related product catalogues as BIM data exchange models. It describes the content of product catalogues
and the mapping of the content to a data format.
This data format provides the opportunity to search and select product data together with accessory
data which can be read into software applications for planning, designing, calculating and simulating as
well as for facility management.
— ISO 16757-2 describes the concept of geometry of the building services product data of a product
catalogue in form of 2D or 3D symbols and 3D shape models and specifies the required spaces and ports.
It contains the fundamental concepts and assumptions about the parametric geometry of special
products, used in planning software applications, e.g. for air conditioning systems such as ducts and
transitions between different forms. It also contains a concept for representing products as 3D solid
models made from thin sheet metal.
— ISO 16757-4 describes the data structures that are required in a data dictionary to support the exchange
of product data from manufacturers to designers of building services systems.
It defines subject kinds to distinguish subjects representing products from subjects representing
features of products like ports and in/outlets, it defines relationship types and a number of property
v
ISO 16757-5:2025(en)
kinds, in particular dynamic properties for the description of the behaviour of a product under changing
conditions. In addition, ISO 16757-4 defines a mapping to the dictionary model of ISO 12006-3.
vi
International Standard ISO 16757-5:2025(en)
Data structures for electronic product catalogues for building
services —
Part 5:
Product catalogue exchange format
1 Scope
This document describes how product catalogue data for building services products is exchanged by means
of ISO 16739-1 (Industry Foundation Classes, IFC) and EN 17549-2 from manufacturers to designers of
building services systems.
This document specifies how the product catalogue structures and content are set up using the definitions
stored in a data dictionary.
In scope of this document are:
— processes for the provision and exchange of product catalogues;
— rules for the geometrical representation of products;
— representation of products, product classes, ports, in/outlets, components and accessories by using IFC;
— representation of properties in IFC and the use of IFC constraints for the representation of product
variants;
— representation of parametric geometry and the generation of IFC geometries for selected variants;
— calculation of article number.
The resulting product catalogue can be used by designers to select the desired products and integrate them
into their model of the building services system.
The expected audience of this document are software providers for the built environment sector and
professionals working in the sector who create product catalogues or use product catalogues by means of
software tools.
Not in scope of this document is the representation of properties in data dictionaries. The use of data
dictionaries is described in ISO 16757-4.
2 Normative references
The following document is 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 6707-1, Buildings and civil engineering works — Vocabulary — Part 1: General terms
ISO 16757-1, Data structures for electronic product catalogues for building services — Part 1: Concepts,
architecture and model
ISO 16757-4, Data structures for electronic product catalogues for building services - Part 4: Data dictionary
structures for product catalogues
ISO 16757-5:2025(en)
ISO 23386:2020, Building information modelling and other digital processes used in construction — Methodology
to describe, author and maintain properties in interconnected data dictionaries
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16757-1, ISO 16757-4, ISO 6707-1
and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
object
any part of the perceivable or conceivable world
Note 1 to entry: An object is something abstract or physical toward which thought, feeling, or action is directed.
[SOURCE: ISO 12006-2:2015, 3.1.1]
3.2
attribute
data element for the computer-sensible description of a property, a relation or a class
[SOURCE: ISO 22274:2013, 3.2, modified — EXAMPLE has been removed.]
3.3
constraint
logical expression that restricts the possible values for one or several properties
3.4
data dictionary
centralized repository of data about data or data elements such as meaning, relationships to other data,
origin, usage, and format
[SOURCE: ISO 23386:2020, 3.9, modified — The words "information about data" have been replaced with
"data about data or data elements"; note 1 to entry has been removed.]
3.5
function
modular unit of programming code to perform specific tasks with algorithms and formulae for the
calculation of computable, dynamic properties
Note 1 to entry: The representation of functions and formulae follows a simple program script syntax.
3.6
technical system
interconnected products for the supply and disposal of materials and energy to buildings
4 Overview of supported processes
4.1 General
This document describes the definition and handling of product catalogues that use IFC as their basic
exchange format. In the following these product catalogues are referred to as IFC catalogues. The main
processes, supported by the ISO 16757 series, are the definition of product catalogues as IFC catalogues
with content from the manufacturer’s catalogue, selection of individual products and insertion into the BIM
project model (see Figure 1).
ISO 16757-5:2025(en)
Figure 1 — Main processes supported by the ISO 16757 series
The definitions of product classes (in ISO 16757-4 called product subjects), product properties and property
attributes shall be organized in accordance with ISO 23386:2020, Clauses 5 and 6, by commissions of
experts. This also includes the definitions of the functions for calculating the values of dynamic properties.
The elements defined in the commissions of experts can be provided in list form.
Experts introduce the product classes and their properties into data dictionaries according to ISO 12006-3
and ISO 16757-4. This can be done via the special user interfaces of the dictionaries or by transferring the
list of elements via provided application programming interfaces (API).
Three roles can be described for the creation, provision and use of product catalogues:
a) product manufacturer (possibly supported by service providers);
b) catalogue provider;
c) end user.
4.2 Creation of product catalogues using the definitions in the data dictionary
The required definitions of product classes and related properties as well as the classes of ports and in/
outlets can be read from the central data dictionary via an API.
The hierarchy of product classes and product property classes is also specified by the definitions in the data
dictionary.
The data dictionary contains also the defined names and parameter list of all needed functions.
The responsibilities of product manufacturers or their service providers are:
— to define the products of their product catalogues, including their variants and the grouping of variants;
— to define the properties of their products and their values or domains of values;
— to translate these values or domains of values in appropriate languages (if necessary), re-using as much
as possible translated lists of values provided by the dictionary;
— to define the constraints between properties;
— to define the formulas that will allow the calculation of values of dynamic properties (e.g. pressure loss)
on selected products;
— to generate a meta-object file describing each configurable product, using its preferred file format;
ISO 16757-5:2025(en)
— to code a JavaScript function that will transform the meta-object into an IFC file;
— to provide to product catalogue providers the 3 elements that define each product: EN 17549-2:2023
properties and constraints, a geometrical meta-object and a JavaScript function to transform it into IFC files.
4.3 Provision of the product catalogue
On web portals, realised by product catalogue providers, manufacturers present their main product classes
with possible areas of application, boundary conditions and special property values and offer the product
data exchange files for download. Special web applications can be used for the presentation.
The responsibilities of product catalogue providers are:
— to collect product catalogues conforming to this document from multiple manufacturers into a database
(EN 17549-2 properties, meta-objects, JavaScript functions that will transform the meta-object into an
IFC file);
— to allow end-users to interact with data dictionaries to retrieve semantics of properties, product classes,
relationships;
— to provide a search mechanism to browse product catalogues from multiple manufacturers;
— to provide a decision support mechanism to help end-users configure the products;
— Once the end-user has configured the product:
— to generate the configured EN 17549-2 file;
— to generate the IFC file describing the geometric representation of the configured product, by
running the JavaScript function provided by the manufacturer;
— to provide a download mechanism for the end-user.
4.4 Product determination in the product catalogue
Planning and other software applications guide the user (designer) in determining a single product and/
or in assembling a product group of components and accessories based on product classes and product
property values.
Based on the determined product classes, product property values, components and accessories, the
software applications create the corresponding article numbers.
The responsibilities of product catalogue end-users are:
— to perform end-user search through multiple product catalogues;
— to configure the product by assigning values to variable properties;
— to download the configured product (EN 17549-2 properties and IFC geometric representation);
— to integrate the configured product into their data base.
4.5 Product integration into the technical system model
The software applications that use prefabricated product catalogues can be planning systems, CAD systems,
calculation systems or combinations of these, for example. They read the product catalogue data into their
own data structure and integrate it into their system model. CAD systems create the product-related
graphical symbol, design and connection data for the determined products.
The software applications can calculate and simulate the behaviour of the products in building services
systems with the help of the property values and the calculation of dynamic properties based on the
technical rules specified by the product manufacturer.
ISO 16757-5:2025(en)
4.6 Data exchange of the technical system model
Software applications can transfer with the technical system model the links to the product classes, the
product property values, components and accessories as well as the corresponding article numbers of the
products via IFC for further (actual) data exchange with external software applications.
4.7 Use of product catalogues according to the ISO 16757 series
The way in which end users use product catalogues according to the ISO 16757 series depends on the
orientation of the software systems they use.
Pure CAD systems that do not have the option of calculating building services may only be able to display the
geometry of the products from the product catalogues. This may, for example, already fulfil the requirements
of the preliminary planning of technical systems. Using the product catalogues automatically ensures that
the shapes and dimensions of products exist.
Pure calculation software, on the other hand, are interested in certain dimensions (pipe lengths, heater
surfaces) from the product catalogue. If the CAD pre-planning described above exists, the correct dimension
values can be taken from there. Dynamic properties, using manufacturer-related algorithms and values, can
enlarge the features of calculation systems.
The more planning and calculation are coordinated in integrated software systems, the greater the benefit
of using the product catalogues according to the ISO 16757 series.
5 Product representation
5.1 Part numbers
Every deliverable product has a combination of property values. But not all theoretically possible
combinations of values lead to a deliverable product. Some combinations contradict each other (tiny radiator
with very large heat radiation, large valve with very small ports); some combinations are not producible.
To determine and order a specific product from a product catalogue, it is generally sufficient to specify one
or several part numbers.
For configurable products, the part numbers are defined on the basis of the values of specific properties,
from which the part numbers can be calculated. The following types of products in product catalogues can
be distinguished:
a) Configured products
For these products, part numbers are clearly assigned in the product catalogue. The quantity of property
values is manageable.
b) Configurable products
The (descriptive) part numbers for these products are only generated when the order is placed by
combining property values. Depending on the number of property value lists that can be combined,
billions of possible variants are conceivable in practice. It is possible that some part numbers are never
generated for certain combinations of property values.
5.2 Geometry
The content of an electronic product catalogue also includes the geometry of the products. The geometry
shall be usable as a model for planning in CAD systems and for calculations (e.g. in pressure loss calculation,
heat transfer and sound emission).
As the geometry cannot be defined in a data dictionary according to ISO 16757-4, the mapping of the
geometry in an electronic product catalogue is described in this subclause.
ISO 16757-5:2025(en)
Every product has geometric data - at least it can be represented by a graphic symbol.
The geometry from product catalogues is not used for product manufacture and therefore has no production-
relevant data such as demolding slopes or punching radii.
Therefore, a pure constructive solid geometry (CSG) description of the product geometry is usually sufficient.
Basic geometric elements such as lines, circles and arcs and geometric solids such as cuboids, cylinders,
spheres, cones and Boolean operations are usually sufficient to describe the representation of products.
This applies in particular to the geometry of configurable products such as pipes, air ducts, radiators,
silencers or fire dampers, for which arbitrary dimensions can sometimes be specified.
In most cases, an overly realistic geometric representation (see Figure 2) is not desired, as thousands of
similar but not equal, elaborately represented products can be used in a building model. This results in a
high loss of performance. In addition, these detailed geometries become colour-filled patches in the scales of
overview representations, which no longer allow the user to differentiate between them.
Figure 2 — Overly realistic geometric representation
Depending on the level of information need, the user can request differently detailed geometries according
to the ISO 7817 series.
Levels of geometry that can be defined individually by the user require not only a great deal of effort on the
part of the user, but also a further examination of the result and possibly a repeated readjustment of the
level of geometry in dialogue with the creator of the model.
For the user of a product catalogue, on the other hand, it is important to be able to directly address certain
predefined types of more or less detailed geometries.
ISO 16757-5:2025(en)
For this purpose, 14 types of geometric representation are defined and shall be used in product catalogues:
— Symbolic geometry (see 5.3):
— Type 1: Symbolic geometry (normal)
It represents the main function of a product.
— Type 2: Symbolic geometry (detailed)
It represents the explicit main and sub functions of a product.
— Type 3: Symbolic geometry (port)
The location and direction in piping and instrumentation diagram (P & ID) (the ISO 10628 series)
can be recognized.
— Type 4: Symbolic geometry (in/outlet)
The location and direction in P & ID (the ISO 10628 series) can be recognized.
— Shape geometry (see 5.4):
— Type 5: Shape geometry (minimized)
The main product class can be recognized.
— Type 6: Shape geometry (normal)
The product direction for installation (front/backside) can be recognized.
— Type 7: Shape geometry (realistic)
All main geometric properties of a product can be recognized.
— Port geometry (see 5.5):
— Type 8: Shape geometry (port)
Location and direction at the shape geometry can be recognized.
— In/outlet geometry (see 5.6):
— Type 9: Shape geometry (in/outlet)
Location and direction at the shape geometry can be recognized.
— Space geometry (see 5.7)
— Type 10: Overall space
3D shape of space that includes the entire product space and all other spaces.
— Type 11: Operation space
3D shape of space that enables the product to be operated.
— Type 12: Access space
3D shape of space that enables the product to be accessed.
— Type 13: Transportation space
3D shape of space that enables the product to be transported.
ISO 16757-5:2025(en)
— Type 14: Installation space
3D shape of space that enables the product to be installed.
5.3 Symbolic geometry
Graphical symbols represent the technical functions of a product. There are two levels of graphical symbols,
less detailed graphical symbols (normal) (see Figure 3) and high detailed graphical symbols (see Figure 4).
In addition, graphical symbols for ports (see Figure 5) and in/outlets (see Figure 6) can be attached to
graphical symbols of products.
All graphical symbols shall be represented as 3D geometry. They are designed with X-Y coordinates and
a Z-component of zero. Thus, they can be used in a CAD application not only in P & ID schemas but also in
isometric drawings.
a) Compressor general (ISO 14617-2-2302) b) Pump general (ISO 14617-2-2301)
Figure 3 — Examples of symbolic geometry representing the main function of a product
a) Compressor with alternative directions b) Compressor with alternative directions
(ISO 14617-2-2304) (ISO 14617-2-2303)
Figure 4 — Examples of symbolic geometry representing the explicit
main- and sub-functions of a product
Figure 5 — Example of geometric types: graphical symbol: ports at a pump symbol
(application of ISO 14617-2-2303)
Figure 6 — Example of geometric type: graphical symbol: in/outlets at a compressor symbol
(application of ISO 14617-2-2302)
5.4 Shape geometry
ISO 16757-2 defines for one geometric product model the following kinds of shape geometry (see Figure 7):
— Geometric type 5: 3D less detailed (minimized)
ISO 16757-5:2025(en)
— Geometric type 6: 3D more detailed (normal)
— Geometric type 7: 3D highly detailed (realistic)
a) Less detailed (minimized) b) More detailed (normal) c) Highly detailed (realistic)
Figure 7 — Examples of geometric type: shape
The types of shape geometry shall meet the following requirements:
Type 5 is a less detailed 3D shape geometry. It shall be elaborated so far that the main classification into a
product class is possible.
EXAMPLE A type 5 geometry makes it possible to distinguish, for example, a fire damper from a duct, a radiator
from a boiler, a bathtub from a sink and a valve from a pressure gauge.
Geometries of this level shall fulfil two objectives:
— The first objective is to prevent product geometries in overview displays from leading to an accumulation
of strokes that result in 'black' spots.
— The second objective is to minimize the number of geometric elements to ensure the best performance
for CAD systems.
To ensure these objectives, a type 5 geometry of a product shall be limited to three geometric elements.
Type 6 is a more detailed 3D shape geometry. It shall be elaborated so far that a differentiation between
products of different manufacturers is possible. The main geometric differences in the shape design shall be
displayed. The direction of mounting shall be visible.
Type 7 is a highly detailed 3D shape geometry. It shall be elaborated so far that all main geometric properties
of a product are visible. It shall provide a nearly photorealistic view of the product without representing
details of lower interest such as rivets or flat sheet metal seams.
ISO 16757-5:2025(en)
The main target of this level is to present particular products to end users or to create detailed visualizations
in order to highlight particular instances of products in building services system models. The provision of
such detailed geometry is optional.
A product catalogue shall contain at least a type 5 geometry of any product.
See ISO 16757-2 for a detailed description of shape geometry.
5.5 Ports
In the system model, product ports can be connected to ports of other products. They are used from and to
the product for the transfer of substances, energy, forces and signals. For more information about ports see
ISO 16757-4:2025, 4.3.4.2.
Ports shall be set up independently for (see Figure 8):
— the symbolic geometry in geometric type 1 and 2;
— the shape geometry in type 5, 6 and 7.
a) Symbolic geometry b) Shape geometry
(application of ISO 7000-1852)
Figure 8 — Examples: different port positions at symbolic (type 3) and at shape (type 8) geometry
Ports shall be positioned geometrically in the 2D plane or in 3D space only with the port position and port
directions.
No geometric shape data shall be assigned to ports. The shape, for example, of flanges is part of the
product shape.
During operation, the technical values of the media flowing through (volume flow, pressure, temperature,
flow velocity) are assigned to the ports. The values at the connections are taken from the mating connections
of the connected products or used for the subsequent calculations.
The graphical representation of ports lies in the responsibility of the respective CAD system. Connected
ports are not normally shown in the design. A CAD system can provide a graphic warning for connections
that do not match.
In the case of connections between ports, arrow symbols in certain colours, for example, can conve
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