ISO/TR 52018-2:2017

Energy performance of buildings — Indicators for partial EPB requirements related to thermal energy balance and fabric features — Part 2: Explanation and justification of ISO 52018-1

ISO/TR 52018-2:2017 refers to ISO 52018‑1. ISO 52018‑1 gives a succinct enumeration of possible requirements related to thermal energy balance features and to fabric features. It also provides tables for regulators to report their choices in a uniform manner. ISO/TR 52018-2:2017 provides many background considerations that can help both private actors and public authorities, and all stakeholders involved, to take informed decisions. ISO/TR 52018-2:2017 does not contain any normative provision.

Performance énergétique des bâtiments — Indicateurs pour des exigences PEB partielles liées aux caractéristiques du bilan énergétique thermique et du bâti — Partie 2: Explication et justification de l’ISO 52018-1

General Information

• Status: Published
• Publication Date: 20-Jun-2017
• ICS: 91.120.10 - Thermal insulation of buildings
• Technical Committee: ISO/TC 163/SC 2 - Calculation methods
• Drafting Committee: ISO/TC 163/SC 2/WG 15 - Energy Performance calculation methods
• Current Stage: 6060 - International Standard published
• Due Date: 10-Apr-2017
• Completion Date: 21-Jun-2017

Relations

• Consolidated By: ISO 22041:2019 - Refrigerated storage cabinets and counters for professional use — Performance and energy consumption
• Effective Date: 06-Jun-2022

Standards Content (Sample)

TECHNICAL ISO/TR
REPORT 52018-2
First edition
2017-06
Energy performance of buildings —
Indicators for partial EPB
requirements related to thermal
energy balance and fabric features —
Part 2:
Explanation and justification of ISO
52018-1
Performance énergétique des bâtiments — Indicateurs pour
des exigences PEB partielles liées aux caractéristiques du bilan
énergétique thermique et du bâti —
Partie 2: Explication et justification de l’ISO 52018-1
Reference number
ISO/TR 52018-2:2017(E)
©
ISO 2017

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ISO/TR 52018-2:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© 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.
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ii © ISO 2017 – All rights reserved

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ISO/TR 52018-2:2017(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and subscripts . 1
5 General aspects . 2
6 Mix of EPB features with requirements . 3
7 Summer thermal comfort . 3
7.1 Motivation . 3
7.2 Points of attention . 3
7.3 Indicators . 5
7.4 Comparable economic strictness . 5
7.5 New construction/renovation . 6
7.6 Exceptions . 6
8 Winter thermal comfort . 6
9 Energy need for heating, or variants . 6
9.1 Motivation . 6
9.2 Indicators . 7
9.3 Comparable economic strictness . 8
9.4 New construction/renovation . 9
9.5 Exceptions . 9
10 Energy need for cooling, or variants . 9
11 Combination of “needs” . 9
12 Overall thermal insulation of the thermal envelope .10
12.1 Motivation .10
12.2 Indicators .10
12.3 Comparable economic strictness .10
12.4 New construction/renovation .11
12.5 Intermediate forms between overall and individual thermal insulation .11
13 Thermal insulation of individual elements of the thermal envelope .11
13.1 Motivation .11
13.2 Indicators .12
13.3 Points of attention .12
13.4 Comparable economic strictness .14
13.5 New construction/renovation .14
13.6 Exceptions .15
14 Thermal bridges .15
14.1 General .15
14.2 Motivation .15
14.3 Requirement setting .15
14.4 Alternative routes .16
14.5 New construction/renovation .17
14.6 Further information .18
15 Window energy performance .18
15.1 Motivation .18
15.2 Indicators .18
15.3 Points of attention .18
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ISO/TR 52018-2:2017(E)

15.4 New construction/renovation .18
16 Airtightness.19
16.1 Motivation .19
16.2 Indicator and comparable economic strictness .19
16.3 New construction/renovation .20
16.4 Measurement .20
16.5 Further information .21
17 Solar control .22
Annex A (informative) Input and method selection data sheet — Template.23
Annex B (informative) Input and method selection data sheet — Default choices .24
Annex C (informative) Regional references in line with ISO Global Relevance Policy .26
Annex D (informative) Example method for integrating fictitious cooling into the overall
EPB indicators .27
Annex E (informative) Illustration of the variable value of the heating need per useful floor
area for a given set of technical measures .29
Annex F (informative) An underpinning of an expression for the maximum mean
thermal transmittance .33
Bibliography .37
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ISO/TR 52018-2:2017(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/d irectives).
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/p atents).
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: ww w .iso. org/iso / foreword. html.
ISO/TR 52018-2 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).
A list of all parts in the ISO 52018 series can be found on the ISO website.
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ISO/TR 52018-2:2017(E)

Introduction
Relation between this document and the accompanying International Standard
For proper understanding of the present document, it is necessary to read it in close conjunction,
clause by clause, with ISO 52018-1. Essential information provided in Part 1 is not repeated in this part.
References to a clause refer to the combined content of that clause in both parts 1 and 2. Brief articles
[20] [21] [22]
on the subject can be found in , and .
The set of EPB standards, technical reports and supporting tools
In order to facilitate the necessary overall consistency and coherence, in terminology, approach,
input/output relations and formats, for the whole set of EPB-standards, the following documents and
tools are available:
a) a document with basic principles to be followed in drafting EPB-standards: CEN/TS 16628:2014,
[1]
Energy Performance of Buildings - Basic Principles for the set of EPB standards ;
b) a document with detailed technical rules to be followed in drafting EPB-standards:
CEN/TS 16629:2014, Energy Performance of Buildings - Detailed Technical Rules for the set of EPB-
[2]
standards ;
The detailed technical rules are the basis for the following tools:
1) a common template for each EPB standard, including specific drafting instructions for the relevant
clauses;
2) a common template for each technical report that accompanies an EPB standard or a cluster of EPB
standards, including specific drafting instructions for the relevant clauses;
3) a common template for the spreadsheet that accompanies each EPB (calculation) standard, to
demonstrate the correctness of the EPB calculation procedures.
Each EPB standard follows the basic principles and the detailed technical rules and relates to the
[3]
overarching EPB standard, ISO 52000-1 .
One of the main purposes of the revision of the EPB standards has been to enable that laws and
regulations directly refer to the EPB standards and make compliance with them compulsory. This
requires that the set of EPB standards consists of a systematic, clear, comprehensive and unambiguous
set of energy performance procedures. The number of options provided is kept as low as possible,
taking into account national and regional differences in climate, culture and building tradition, policy
and legal frameworks (subsidiarity principle). For each option, an informative default option is provided
(Annex B).
Rationale behind the EPB technical reports
There is a risk that the purpose and limitations of the EPB standards will be misunderstood, unless
the background and context to their contents – and the thinking behind them – is explained in some
detail to readers of the standards. Consequently, various types of informative contents are recorded
and made available for users to properly understand, apply and nationally or regionally implement the
EPB standards.
If this explanation would have been attempted in the standards themselves, the result is likely to be
confusing and cumbersome, especially if the standards are implemented or referenced in national or
regional building codes.
Therefore each EPB standard is accompanied by an informative technical report, like this one, where
all informative content is collected, to ensure a clear separation between normative and informative
[2]
contents (see CEN/TS 16629 ):
— to avoid flooding and confusing the actual normative part with informative content,
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ISO/TR 52018-2:2017(E)

— to reduce the page count of the actual standard, and
— to facilitate understanding of the set of EPB standards.
[17]
This was also one of the main recommendations from the European CENSE project that laid the
foundation for the preparation of the set of EPB standards.
This document
This document accompanies ISO 52018-1, which forms part of the set EPB standards.
The role and the positioning of the accompanied standard in the set of EPB standards is defined in the
Introduction to ISO 52018-1.
General aspects of EPB indicators, requirements, ratings and certificates and application to the overall
[5] [6]
energy performance of buildings can be found in ISO 52003-1 and ISO/TR 52003-2 .
Accompanying spreadsheet
Because in the accompanying document ISO 52018-1 no calculation procedures are defined, an
accompanying calculation spreadsheet is not relevant.
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TECHNICAL REPORT ISO/TR 52018-2:2017(E)
Energy performance of buildings — Indicators for partial
EPB requirements related to thermal energy balance and
fabric features —
Part 2:
Explanation and justification of ISO 52018-1
1 Scope
This document refers to ISO 52018-1.
ISO 52018-1 gives a succinct enumeration of possible requirements related to thermal energy balance
features and to fabric features. It also provides tables for regulators to report their choices in a uniform
manner. This document provides many background considerations that can help both private actors
and public authorities, and all stakeholders involved, to take informed decisions.
This document does not contain any normative provision.
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 52018-1, Energy performance of buildings – Indicators for partial EPB requirements related to thermal
energy balance and fabric features – Part 1: Overview of options
NOTE More information on the use of EPB module numbers, in all EPB standards, for normative references
to other EPB standards is given in ISO/TR 52000-2.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 52018-1 apply.
[4]
More information on some key EPB terms and definitions is given in ISO/TR 52000-2 .
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
4 Symbols and subscripts
For the purposes of this document, the symbols and subscripts given in ISO 52018-1 apply.
[4]
More information on key EPB symbols and subscripts is given in ISO/TR 52000-2 .
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5 General aspects
This document is fully complementary to ISO 52018-1. For a good comprehension, before reading
a clause in this document, the corresponding (succinct) clause in ISO 52018-1 should be read, as this
document does not repeat the content of ISO 52018-1, but only provides additional information.
This document contains many straightforward considerations with which many readers may already be
familiar. In order for the text to also provide full support to novices in the field, such basic considerations
have nevertheless been included. On the other hand, commonly circulating argumentations that could
not withstand the test of critical, rational analysis have been omitted. It is self-evident, by the very
nature of the topic, that the treatment can never be fully exhaustive; many additional motivations, for
instance influenced by specific local conditions, may influence the final choice of the mix of energy
features and indicators for which requirements are set.
For each of the partial EPB features enumerated in ISO 52018-1, this document formulates background
considerations with respect to the following aspects (in as far as applicable):
— possible motivations,
— possible indicators,
— comparable economic strictness of the requirements,
— practical points of attention,
— testing,
— new construction and renovation issues,
— exceptions,
— other.
Achieving a good indoor environmental quality is one of the major objectives when designing buildings
(first and foremost for the people in the building, but also for the proper preservation of any –specific–
goods in the building). The topic of indoor environment is thematically and technically closely
related to the energy efficiency of buildings, and both aspects are therefore logically considered in an
integrated manner when building regulations are established. All the partial EPB features discussed
in ISO 52018-1 and in this document are listed in Table 1 together with an indication whether indoor
environment and/or energy efficiency is (are) usually the main motivation(s). (There may of course still
be other possible reasons for setting a requirement, such as fabric preservation, but such other reasons
are not visualized in the summary table.) Requirements on most EPB features may to a greater or lesser
extent serve both purposes. The nuances are further discussed in each of the clauses.
Table 1 — Overview of the different partial EPB features
Clause Partial EPB feature Indoor Energy
environment efficiency
6 summer thermal comfort X (X)
7 winter thermal comfort X (X)
8 energy “need” for heating, or variants (X) X
9 energy “need” for cooling, or variants (X) X
10 combination of “needs” X
11 overall thermal insulation of the envelope X
12 thermal insulation of individual envelope elements X X
13 thermal bridges X X
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Table 1 (continued)
Clause Partial EPB feature Indoor Energy
environment efficiency
14 window energy rating X
15 airtightness X X
16 solar control X X
Often, an important consideration when setting EPB requirements is to achieve a strictness that
is more or less cost optimal (at an assumed scenario of the future energy prices) for each individual
[5]
construction project. This issue is explained in a general manner in ISO 52003-1 and ISO/TR 52003-
[6]
2 . In this document, this aspect is discussed in a more practical manner for each of the EPB features.
6 Mix of EPB features with requirements
No additional information beyond ISO 52018-1.
7 Summer thermal comfort
7.1 Motivation
If there are complaints by the building users about the indoor environmental quality, it often includes
summer thermal comfort. The occurrence of this problem can potentially be aggravated by EPB
building regulations if these are not well-considered and well-equilibrated. Partial EPB requirements
only dealing with the heating aspect may lead designer teams to maximize solar gains in winter, while
neglecting the summer impact. And in uncooled buildings, or if active cooling would not be included in
the overall energy performance assessment, even an overall EPB requirement can cause such single-
sided design.
Setting a summer thermal comfort requirement may thus be an important complement in order to
achieve a balanced, integral building design that performs well in all respects, both in winter and in
summer. In addition, good summer indoor conditions strongly reduce the probability that active cooling
will be installed later on during the lifetime of the building. In this manner such requirement thus also
contributes in the long run to the energy saving goal.
7.2 Points of attention
Special consideration should be given to the potential issue that a diverging approach between uncooled
and actively cooled buildings might result in unwanted consequences.
For instance, if overall EPB requirements and/or partial EPB requirements (e.g., on the cooling “need”)
in actively cooled buildings are much more severe than in uncooled buildings, and if at the same
time there is no attention in the building regulation for summer comfort in uncooled buildings, then
the regulation might cause (especially in the segment of the construction market that is first cost
dominated) an increase of uncooled building designs with uncomfortable summer conditions, resulting
in the installation of (potentially less efficient) active cooling any time after construction.
Vice-versa, a requirement on summer thermal comfort in uncooled buildings that is not matched with
(overall and/or partial) EPB requirements that equally impact cooled buildings, might possibly cause
an undesired immediate shift in new construction towards actively cooled buildings for the sole reason
of a regulatory requirement that is technically and/or economically more easily satisfied.
A possible approach to avoid such divergent regulatory treatment between uncooled and cooled
buildings is to simply set for a given building category (such as dwellings, offices, schools, etc.) the
same type of requirement and the same strictness for each building, independently of the fact whether
or not the building is actively cooled. The requirement can either be a cooling “need” requirement
(see Clause 10) for all buildings (so, also in buildings that are not actively cooled) or alternatively a
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summer thermal comfort requirement for all buildings (whereby in the evaluation of this requirement,
it is assumed that
...