EN ISO 14683:2017

Thermal bridges in building construction - Linear thermal transmittance - Simplified methods and default values (ISO 14683:2017)

ISO 14683:2007 deals with simplified methods for determining heat flows through linear thermal bridges which occur at junctions of building elements.
ISO 14683:2007 specifies requirements relating to thermal bridge catalogues and manual calculation methods.
Default values of linear thermal transmittance are given in Annex A for information.

Wärmebrücken im Hochbau - Längenbezogener Wärmedurchgangskoeffizient - Vereinfachte Verfahren und Standardwerte (ISO 14683:2017)

Dieses Dokument behandelt vereinfachte Verfahren zur Bestimmung der Wärmeströme durch linienförmige Wärmebrücken, die an Bauteilverbindungen auftreten.
Dieses Dokument legt Anforderungen an Wärmebrückenkataloge und manuelle Berechnungsverfahren fest.
Im Anhang C sind Standardwerte des längenbezogenen Wärmedurchgangskoeffizienten angegeben.
ANMERKUNG   Tabelle 1 in der Einleitung zeigt die relative Position dieses Dokuments innerhalb des EPB Normen-pakets im Kontext der in ISO 52000 1 dargelegten modularen Struktur.

Ponts thermiques dans les bâtiments - Coefficient linéique de transmission thermique - Méthodes simplifiées et valeurs par défaut (ISO 14683:2017)

L'ISO 14683:2017 traite des méthodes simplifiées pour la détermination des flux thermiques à travers les ponts thermiques linéaires qui se produisent aux jonctions de parois de bâtiments.
L'ISO 14683:2017 spécifie des exigences concernant les catalogues de ponts thermiques et les méthodes manuelles de calcul.
Les valeurs par défaut du coefficient linéique de transmission thermique sont indiquées dans l'Annexe C.
NOTE       Le Tableau 1 de l'Introduction indique la position relative de l'ISO 14683:2017 dans la série de normes PEB dans le contexte de la structure modulaire définie dans l'ISO 52000‑1.

Toplotni mostovi v stavbah - Linearna toplotna prehodnost - Poenostavljena metoda in privzete vrednosti (ISO 14683:2017)

ISO 14683:2007 obravnava poenostavljene metode za določevanje toplotnih tokov skozi linearne toplotne mostove ob spojih stavbnih elementov.
ISO 14683:2007 določa zahteve v povezavi s katalogi toplotnih mostov in ročnimi računskimi metodami. Privzete vrednosti linearne toplotne prehodnosti so informativno podane v dodatku A.

General Information

• Status: Published
• Publication Date: 18-Jul-2017
• Withdrawal Date: 30-Jan-2018
• ICS: 91.120.10 - Thermal insulation of buildings
• Technical Committee: CEN/TC 89 - Thermal performance of buildings and building components
• Drafting Committee: CEN/TC 89 - Thermal performance of buildings and building components
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 19-Jul-2017
• Completion Date: 19-Jul-2017
• Directive: 2010/31/EU - Directive 2010/31/eu of the European Parliament and of the Council of 19 May 2010 on the energy performance of buildings (recast)
• Directive: 89/106/EEC - Construction products
• Mandate: M/480 - Mandate to CEN, CENELEC and ETSI for the elaboration and adoption of standards for a methodology calculating the integrated energy performance of buildings and promoting the energy efficiency of buildings, in accordance with the terms set in the recast of the Directive on the energy performance buildings (2010/31/EU)
• Ref Project: SIST EN ISO 14683:2017 - Thermal bridges in building construction - Linear thermal transmittance - Simplified methods and default values (ISO 14683:2017)

Relations

• Replaces: EN ISO 14683:2007 - Thermal bridges in building construction - Linear thermal transmittance - Simplified methods and default values (ISO 14683:2007)
• Effective Date: 26-Jul-2017

Overview

EN ISO 14683:2017 - "Thermal bridges in building construction - Linear thermal transmittance - Simplified methods and default values" is the 2017 CEN/ISO standard for assessing heat flows caused by linear thermal bridges at junctions of building elements. It provides simplified calculation approaches, requirements for thermal-bridge catalogues and manual methods, and includes default linear thermal transmittance (psi) values in the annexes for use where detailed data are not available. The standard is part of the EPB (energy performance of buildings) set used to support energy performance assessments and regulatory compliance across Europe.

Key Topics and Requirements

• Scope and intent
  • Simplified methods to determine heat flows through linear thermal bridges (junctions between walls, floors, roofs, windows, etc.).
  • Guidance to ensure consistency and transparency in energy performance calculations.
• Methods described
  • Numerical calculations for detailed modelling.
  • Thermal-bridge catalogues: standardized formats and requirements for reusable component data.
  • Manual calculation methods for common junction types when numerical simulation is not available.
• Output and parameters
  • Focus on linear thermal transmittance (ψ‑values) and their influence on overall heat transfer and transmission heat transfer coefficients.
• Documentation and templates
  • Includes an input and method selection data sheet (Annex A) and informative default choices (Annex B). Default psi-values are provided in an annex (see Annex C in the ISO text).
• Accuracy and applicability
  • Specifies available methods and discusses expected accuracy ranges and input data needs, allowing national or regional choices where required.

Applications

• Energy performance assessments and compliance with building energy regulations (EPBD-related methodologies).
• Early-stage design decisions for architects and building engineers to minimize thermal bridging and improve thermal insulation performance.
• Creation and use of thermal bridge catalogues by manufacturers, designers and certifiers.
• Manual or simplified calculations for retrofit projects, product selection, and certification where full 2D/3D numerical analysis is impractical.
• Input for building energy simulation tools where standardized psi-values or catalogue entries are needed.

Who Should Use This Standard

• Architects, structural and building services engineers
• Energy assessors and building certifiers
• Product manufacturers and façade/assembly designers
• Regulators and authorities adopting EPB standards or setting national parameters

Related Standards

• Part of the EPB (energy performance of buildings) series and developed in collaboration with CEN/TC 89 and ISO/TC 163. It supersedes previous editions (ISO 14683:2007) and supports harmonized energy performance calculation across member states.

Keywords: EN ISO 14683:2017, thermal bridges, linear thermal transmittance, psi-values, thermal bridge catalogues, simplified methods, energy performance of buildings, EPBD, CEN, ISO.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2017
1DGRPHãþD
SIST EN ISO 14683:2008
Toplotni mostovi v stavbah - Linearna toplotna prehodnost - Poenostavljena
metoda in privzete vrednosti (ISO 14683:2017)
Thermal bridges in building construction - Linear thermal transmittance - Simplified
methods and default values (ISO 14683:2017)
Wärmebrücken im Hochbau - Längenbezogener Wärmedurchgangskoeffizient -
Vereinfachte Verfahren und Anhaltswerte (ISO 14683:2017)
Ponts thermiques dans les bâtiments - Coefficient linéique de transmission thermique -
Méthodes simplifiées et valeurs par défaut (ISO 14683:2017)
Ta slovenski standard je istoveten z: EN ISO 14683:2017
ICS:
91.120.10 Toplotna izolacija stavb Thermal insulation of
buildings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 14683
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2017
EUROPÄISCHE NORM
ICS 91.120.10 Supersedes EN ISO 14683:2007
English Version
Thermal bridges in building construction - Linear thermal
transmittance - Simplified methods and default values (ISO
14683:2017)
Ponts thermiques dans les bâtiments - Coefficient Wärmebrücken im Hochbau - Längenbezogener
linéique de transmission thermique - Méthodes Wärmedurchgangskoeffizient - Vereinfachte Verfahren
simplifiées et valeurs par défaut (ISO 14683:2017) und Standardwerte (ISO 14683:2017)
This European Standard was approved by CEN on 27 February 2017.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14683:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 14683:2017) has been prepared by Technical Committee ISO/TC 163 "Thermal
performance and energy use in the built environment" in collaboration with Technical Committee
CEN/TC 89 “Thermal performance of buildings and building components” the secretariat of which is
held by SIS.
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 January 2018 and conflicting national standards shall
be withdrawn at the latest by January 2018.
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.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
This document is part of the set of standards and accompanying technical reports on the energy
performance of buildings and has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association (Mandate M/480, see reference [EF3] below).
Directive 2010/31/EU recasting the Directive 2002/91/EC on energy performance of buildings (EPBD,
[EF4]) promotes the improvement of the energy performance of buildings within the European Union,
taking into account all types of energy uses (heating, lighting, cooling, air conditioning, ventilation) and
outdoor climatic and local conditions, as well as indoor climate requirements and cost effectiveness
(Article 1).
The directive requires Member States to adopt measures and tools to achieve the prudent and rational
use of energy resources. In order to achieve those goals, the EPBD requires increasing energy efficiency
and the enhanced use of renewable energies in both new and existing buildings. One tool for this is the
application by Member States of minimum requirements on the energy performance of new buildings
and for existing buildings that are subject to major renovation, as well as for minimum performance
requirements for the building envelope if energy-relevant parts are replaced or retrofitted. Other tools
are energy certification of buildings, inspection of boilers and air-conditioning systems.
The use of European standards increases the accessibility, transparency and objectivity of the energy
performance assessment in the Member States facilitating the comparison of best practices and
supporting the internal market for construction products. The use of EPB standards for calculating
energy performance, as well as for energy performance certification and the inspection of heating
systems and boilers, ventilation and air-conditioning systems will reduce costs compared to developing
different standards at national level.
The first mandate to CEN to develop a set of CEN EPBD standards (M/343, [EF1]), to support the first
edition of the EPBD ([EF2]) resulted in the successful publication of all EPBD related CEN standards in
2007-2008.
Mandate M/480 was issued to review the mandate M/343 as the recast of the EPBD raised the need to
revisit the standards and reformulate and add standards so that they become on the one hand
unambiguous and compatible, and on the other hand a clear and explicit overview of the choices,
boundary conditions and input data that need to be defined at national or regional level. Such national
or regional choices remain necessary, due to differences in climate, culture and building tradition,
policy and legal frameworks. Consequently, the set of CEN EPBD standards published in 2007-2008 had
to be improved and expanded on the basis of the recast of the EPBD.
The EPB standards are flexible enough to allow for necessary national and regional differentiation and
facilitate Member States implementation and the setting of requirements by the Member States.
Further target groups are users of the voluntary common European Union certification scheme for the
energy performance of non-residential buildings (EPBD article 11.9) and any other regional (e.g. pan
European) parties wanting to motivate their assumptions by classifying the building energy
performance for a dedicated building stock.
This document supersedes EN ISO 14683:2007.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
References:
[EF1] EPBD, Directive 2002/91/EC of the European Parliament and of the Council of 16 December
2002 on the energy performance of buildings
[EF2] EPBD Mandate M/343, Mandate to CEN, CENELEC and ETSI for the elaboration and adoption of
standards for a methodology calculating the integrated energy performance of buildings and estimating
the environmental impact, in accordance with the terms set forth in Directive 2002/91/EC , 30 January
[EF3] Mandate M/480, Mandate to CEN, CENELEC and ETSI for the elaboration and adoption of
standards for a methodology calculating the integrated energy performance of buildings and promoting
the energy efficiency of buildings, in accordance with the terms set in the recast of the Directive on the
energy performance of buildings (2010/31/EU), 14 December 2010
[EF4] EPBD, Recast of the Directive on the energy performance of buildings (2010/31/EU). 14
December 2010
Endorsement notice
The text of ISO 14683:2017 has been approved by CEN as EN ISO 14683:2017 without any modification.

INTERNATIONAL ISO
STANDARD 14683
Third edition
2017-06
Thermal bridges in building
construction — Linear thermal
transmittance — Simplified methods
and default values
Ponts thermiques dans les bâtiments — Coefficient linéique de
transmission thermique — Méthodes simplifiées et valeurs par défaut
Reference number
ISO 14683:2017(E)
©
ISO 2017
ISO 14683:2017(E)
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

ISO 14683:2017(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and subscripts . 2
4.1 Symbols . 2
4.2 Subscripts . 3
5 Description of the method . 3
5.1 Output . 3
5.2 General description . 3
5.3 Influence of thermal bridges on overall heat transfer . 3
5.3.1 Transmission heat transfer coefficient . 3
5.3.2 Linear thermal transmittance . 4
5.3.3 Internal and external dimensions . 4
6 Methods for determination of linear thermal transmittance . 5
6.1 Output data . 5
6.2 Calculation time intervals . 5
6.3 Input data . 5
6.4 Available methods and expected accuracy . 6
6.5 Numerical calculations . 6
6.6 Thermal bridge catalogues . 6
6.7 Manual calculation methods . 7
7 Default values of linear thermal transmittance . 7
Annex A (normative) Input and method selection data sheet — Template .8
Annex B (informative) Input and method selection data sheet — Default choices .10
Annex C (normative) Default values of linear thermal transmittance .12
Bibliography .25
ISO 14683:2017(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 on 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 the following
URL: w w w . i s o .org/ iso/ foreword .html.
ISO 14683 was prepared by ISO Technical Committee ISO/TC 163, Thermal performance and energy use
in the built environment, Subcommittee SC 2, Calculation methods, in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 89, Thermal performance of
buildings and building components, in accordance with the Agreement on technical cooperation between
ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 14683:2007), which has been technically
revised.
The changes in the third edition are mostly editorial. The document has been re-drafted according to
CEN/TS 16629:2014.
iv © ISO 2017 – All rights reserved

ISO 14683:2017(E)
Introduction
This document is part of a series aimed at the international harmonization of the methodology for
assessing the energy performance of buildings. Throughout, this series is referred to as a “set of EPB
standards”.
All EPB standards follow specific rules to ensure overall consistency, unambiguity and transparency.
All EPB standards provide a certain flexibility with regard to the methods, the required input data and
references to other EPB standards, by the introduction of a normative template in Annex A and Annex B
with informative default choices.
For the correct use of this document, a normative template is given in Annex A to specify these choices.
Informative default choices are provided in Annex B.
The main target groups for this document are architects, engineers and regulators.
Use by or for regulators: In case the document is used in the context of national or regional legal
requirements, mandatory choices may be given at national or regional level for such specific
applications. These choices (either the informative default choices from Annex B or choices adapted to
national/regional needs, but in any case following the template of Annex A) can be made available as
national annex or as separate (e.g. legal) document (national data sheet).
NOTE 1 So in this case:
— the regulators will specify the choices;
— the individual user will apply the document to assess the energy performance of a building, and thereby use
the choices made by the regulators.
Topics addressed in this document can be subject to public regulation. Public regulation on the same
topics can override the default values in Annex B. Public regulation on the same topics can even, for
certain applications, override the use of this document. Legal requirements and choices are in general
not published in standards but in legal documents. In order to avoid double publications and difficult
updating of double documents, a national annex may refer to the legal texts where national choices
have been made by public authorities. Different national annexes or national data sheets are possible,
for different applications.
It is expected, if the default values, choices and references to other EPB standards in Annex B are not
followed due to national regulations, policy or traditions, that:
— national or regional authorities prepare data sheets containing the choices and national or regional
values, according to the model in Annex A. In this case a national annex (e.g. NA) is recommended,
containing a reference to these data sheets;
— or, by default, the national standards body will consider the possibility to add or include a national
annex in agreement with the template of Annex A, in accordance to the legal documents that give
national or regional values and choices.
Further target groups are parties wanting to motivate their assumptions by classifying the building
energy performance for a dedicated building stock.
More information is provided in the Technical Report (ISO/TR 52019-2) accompanying this document.
The subset of EPB standards prepared under the responsibility of ISO/TC 163/SC 2 cover inter alia:
— calculation procedures on the overall energy use and energy performance of buildings;
— calculation procedures on the internal temperature in buildings (e.g. in case of no space heating or
cooling);
— indicators for partial EPB requirements related to thermal energy balance and fabric features;
ISO 14683:2017(E)
— calculation methods covering the performance and thermal, hygrothermal, solar and visual
characteristics of specific parts of the building and specific building elements and components, such
as opaque envelope elements, ground floor, windows and facades.
ISO/TC 163/SC 2 cooperates with other technical committees for the details on appliances, technical
building systems, indoor environment, etc.
This document provides the means (in part) to assess the contribution that building products and
services make to energy conservation and to the overall energy performance of buildings.
This document deals with methods for assessing thermal bridges, which give rise to changes in heat
flow rates and surface temperatures compared with those of the unbridged structure. These heat
flow rates and temperatures can be precisely determined by numerical calculation in accordance with
ISO 10211. However, for linear thermal bridges, it is often convenient to use simplified methods or
tabulated values to obtain an estimate of their linear thermal transmittance.
The effect of repeating thermal bridges which are part of an otherwise uniform building element, such
as wall ties penetrating a thermal insulation layer or mortar joints in lightweight blockwork, needs
to be included in the calculation of the thermal transmittance of the building element concerned, in
accordance with ISO 6946.
Although not covered by this document, thermal bridges can also give rise to low internal surface
temperatures, with an associated risk of surface condensation or mould growth.
Table 1 shows the relative position of this document within the set of EPB standards in the context of
the modular structure as set out in ISO 52000-1.
NOTE 2 In ISO/TR 52000-2, the same table can be found, with, for each module, the numbers of the relevant
EPB standards and accompanying technical reports that are published or in preparation.
NOTE 3 The modules represent EPB standards, although one EPB standard could cover more than one module
and one module could be covered by more than one EPB standard, for instance a simplified and a detailed method
respectively. See also Clause 2 and Tables A.1 and B.1.
vi © ISO 2017 – All rights reserved

ISO 14683:2017(E)
Table 1 — Position of this document (in casu M2–5) within the modular structure of the set of
EPB standards
Building
Overarching Technical building systems
(as such)
Buil
De Do ding
Hu
hu mes auto
Sub Ven mi PV,
Descrip Descrip Descrip Hea Coo mi tic Ligh ma
mo tila difi win
tions tions tions ting ling difi hot ting tion
dule tion ca d, .
ca wat and
tion
tion er cont
rol
sub1 M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11
1 General General General
Common
terms and Buil
definitions; ding
a
2 Needs
symbols, energy
units and needs
subscripts
(Free)
Indoor Maxi
condi- mum
3 Applications
tions load and
without power
systems
Ways to Ways to
Ways to ex- express express
4 press energy energy energy
performance perfor- perfor-
mance mance
Heat
Building
trans- Emis-
categories ISO
5 fer by sion and
and building 14683
trans- control
boundaries
mission
Heat
Building oc- transfer Distri-
cupancy and by infil- bution
operating tration and
conditions and ven- control
tilation
Aggregation
of energy Internal Storage
7 services heat and
and energy gains control
carriers
Solar Genera-
Building
8 heat tion and
zoning
gains control
Load
Building
dis-
dy-
Calculated patch-
namics
9 energy per- ing and
(ther-
formance operat-
mal
ing con-
mass)
ditions
a
The shaded modules are not applicable.
ISO 14683:2017(E)
Table 1 (continued)
Building
Overarching Technical building systems
(as such)
Buil
De Do ding
Hu
hu mes auto
Sub Ven mi PV,
Descrip Descrip Descrip Hea Coo mi tic Ligh ma
mo tila difi win
tions tions tions ting ling difi hot ting tion
dule tion ca d, .
ca wat and
tion
tion er cont
rol
sub1 M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11
Meas- Meas-
Measured ured ured
10 energy per- energy energy
formance perfor- perfor-
mance mance
Inspec- Inspec-
11 Inspection
tion tion
Ways to ex-
12 press indoor BMS
comfort
External
13 environment
conditions
Economic
calculation
a
The shaded modules are not applicable.
viii © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 14683:2017(E)
Thermal bridges in building construction — Linear thermal
transmittance — Simplified methods and default values
1 Scope
This document deals with simplified methods for determining heat flows through linear thermal
bridges which occur at junctions of building elements.
This document specifies requirements relating to thermal bridge catalogues and manual calculation
methods.
Default values of linear thermal transmittance are given in Annex C.
NOTE Table 1 in the Introduction shows the relative position of this document within the set of EPB
standards in the context of the modular structure as set out in ISO 52000-1.
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 7345, Thermal insulation — Physical quantities and definitions
ISO 10211, Thermal bridges in building construction — Heat flows and surface temperatures — Detailed
calculations
ISO 13370, Thermal performance of buildings — Heat transfer via the ground — Calculation methods
ISO 13789, Energy performance of buildings — Transmission and ventilation heat transfer coefficients —
Calculation method
ISO 52000-1:2017, Energy performance of buildings — Overarching EPB assessment — Part 1: General
framework and procedures
NOTE 1 Default references to EPB standards other than ISO 52000-1 are identified by the EPB module code
number and given in Annex A (normative template in Table A.1) and Annex B (informative default choice in
Table B.1).
EXAMPLE EPB module code number: M5–5, or M5–5,1 (if module M5–5 is subdivided), or M5–5/1 (if
reference to a specific clause of the standard covering M5–5).
NOTE 2 In this document, there are no choices in references to other EPB standards. NOTE 1 and the EXAMPLE
above are kept to maintain uniformity between all EPB standards.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345 and 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 https:// www .iso .org/ obp/
ISO 14683:2017(E)
3.1
linear thermal bridge
thermal bridge with a uniform cross section along one of the three orthogonal axes
3.2
point thermal bridge
localized thermal bridge whose influence can be represented by a point thermal transmittance
3.3
linear thermal transmittance
heat flow rate in the steady-state divided by length and by the temperature difference between the
environments on either side of a thermal bridge
Note 1 to entry: The linear thermal transmittance is a quantity describing the influence of a linear thermal bridge
on the total heat flow through the building envelope.
3.4
point thermal transmittance
heat flow rate in the steady-state divided by the temperature difference between the environments on
either side of a thermal bridge
Note 1 to entry: The point thermal transmittance is a quantity describing the influence of a point thermal bridge
on the total heat flow through the building envelope.
3.5
transmission heat transfer coefficient
heat flow rate due to thermal transmission through the fabric of a building, divided by the difference
between the environment temperatures on either side of the construction
3.6
EPB standard
[4]
standard that complies with the requirements given in ISO 52000-1, CEN/TS 16628 and
[5]
CEN/TS 16629
Note 1 to entry: These three basic EPB documents were developed under a mandate given to CEN by the
European Commission and the European Free Trade Association and support essential requirements of EU
Directive 2010/31/EU on the energy performance of buildings. Several EPB standards and related documents
are developed or revised under the same mandate.
[SOURCE: ISO 52000-1:2017, 3.5.14]
4 Symbols and subscripts
4.1 Symbols
For the purposes of this document, the symbols given in ISO 52000-1 and the following apply.
Symbol Quantity Unit
A area m
b width m
d thickness m
H heat transfer coefficient W/K
l length m
R thermal resistance m ·K/W
U thermal transmittance W/(m ·K)
θ temperature °C
λ design thermal conductivity W/(m·K)
2 © ISO 2017 – All rights reserved

ISO 14683:2017(E)
Symbol Quantity Unit
Φ heat flow rate W
Ψ linear thermal transmittance W/(m·K)
χ
...