ISO/TR 52000-2:2017

Energy performance of buildings - Overarching EPB assessment - Part 2: Explanation and justification of ISO 52000-1

ISO/TR 52000-2:2017 refers to the overarching EPB-standard, ISO 52000‑1[1]. It contains information to support the correct understanding, use and national implementation of ISO 52000‑1. This includes: - explanation on the procedures and background information and justification of the choices that have been made; - reporting on validation of calculation procedures given in the standard; - explanation for the user and for national standards writers involved with implementation of the set of EPB standards, including detailed examples.

Performance énergétique des bâtiments — Évaluation globale de la PEB — Partie 2: Explication et justification de l'ISO 52000-1

General Information

• Status: Published
• Publication Date: 20-Jun-2017
• ICS: 91.120.10 - Thermal insulation of buildings
• Technical Committee: ISO/TC 163 - Thermal performance and energy use in the built environment
• Drafting Committee: ISO/TC 163/WG 4 - Joint ISO/TC 163 - ISO/TC 205 WG: Energy performance of buildings using holistic approach
• Parallel Committee: ISO/TC 205 - Building environment design
• Current Stage: 6060 - International Standard published
• Start Date: 21-Jun-2017
• Completion Date: 13-Dec-2025

Overview

ISO/TR 52000-2:2017 is a Technical Report supporting the overarching EPB (Energy Performance of Buildings) assessment framework defined in ISO 52000‑1. Published by ISO in 2017, this report provides explanation, justification and background for the procedures and methodological choices in ISO 52000‑1. It is intended to aid correct understanding, national implementation and practical use of the EPB assessment set of standards by supplying validation results, worked examples and detailed guidance.

Key topics and technical scope

ISO/TR 52000-2:2017 expands and clarifies the overarching EPB assessment approach without replacing the normative content of ISO 52000‑1. Major technical topics covered include:

• Overarching framework and modular structure: explanation of the systematic, modular approach for step-by-step implementation of EPB standards.
• Terms, definitions, symbols and units: clear definitions and notation to ensure consistent interpretation across national implementations.
• Preparation and classification: guidance on identifying building types, space categories, assessment types and building services included in EPB.
• Calculated energy performance: explanation of input data categories (product data, system design, operating conditions, constants) and the calculation procedure.
• Measured energy performance and verification: measurement intervals, measurement procedures, and methods for comparing measured vs. calculated energy performance.
• Overall assessment rules: normalization to building size, assessment boundaries, weighting (primary energy, greenhouse gas factors, export handling) and calculation of renewable energy share.
• Zoning and thermal zones: rules for defining thermal zones, spaces and service areas within the EPB framework.
• Validation and examples: reporting of validation of calculation procedures and detailed example cases to support national standard writers and users.

Practical applications and who should use it

ISO/TR 52000-2 is aimed at stakeholders involved in building energy assessment and regulation:

• National standards bodies implementing ISO 52000‑1 in local regulation or building codes.
• Energy assessors and auditors who perform EPB calculations and need guidance on inputs, measurement and reporting.
• Building designers and engineers using EPB methodology for design-stage energy evaluation.
• Policy makers and regulators seeking justification of methodological choices and validation evidence.
• Software developers building compliant calculation tools for building energy performance.

By providing clarification, examples and validation, the report improves consistency in energy performance of buildings assessments and supports reliable national implementation of the ISO EPB framework.

Related standards

• ISO 52000‑1 - Overarching EPB assessment (normative reference; ISO/TR 52000‑2 explains and justifies this standard)
• Other standards in the ISO EPB series (refer to ISO 52000‑1 for the modular numbering and cross-references)

Keywords: ISO/TR 52000-2:2017, energy performance of buildings, EPB assessment, ISO 52000-1, calculation procedures, measured energy performance, primary energy, zoning, building services.

Standards Content (Sample)

TECHNICAL ISO/TR
REPORT 52000-2
First edition
2017-06
Energy performance of buildings —
Overarching EPB assessment —
Part 2:
Explanation and justification
of ISO 52000-1
Performance énergétique des bâtiments — Évaluation globale
de la PEB —
Partie 2: Explication et justification de l’ISO 52000-1
Reference number
©
ISO 2017
© 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
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[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
3.1 Buildings . 2
3.2 Indoor and outdoor conditions. 3
3.3 Technical building systems . 3
3.4 Energy . 4
3.5 Energy performance . 4
3.6 Energy calculation . 4
3.7 General information on terms and definitions . 4
3.7.1 General. 4
3.7.2 Overarching terms and definitions . 4
3.7.3 Difference between definition and specification . 5
3.7.4 Undefined and/or unspecified policy related terms . . 5
4 Symbols, units, subscripts and abbreviations. 5
4.1 Symbols . 5
4.2 Subscripts . 6
4.3 Abbreviations . 6
5 Description of the overarching framework and procedures . 6
5.1 Output of the method . 6
5.2 General description of the procedures and routing . 7
5.3 Selection criteria between the methods . 7
5.4 The over-arching reference modular structure . 7
5.4.1 Purpose . 7
5.4.2 Systematic modular structure of the standards. 7
5.4.3 The connection between the modules – step by step implementation . 8
5.4.4 Systematic consecutive numbering of the standards .10
6 Overarching preparation steps .11
6.1 General .11
6.2 List of types and categories .13
6.2.1 Type of object .13
6.2.2 Building category and space categories.14
6.2.3 Type of application .15
6.2.4 Types of assessment .15
6.2.5 Building services .16
6.3 Identification of types and categories for a specific case .17
6.4 Example cases .17
6.4.1 General.17
6.4.2 Example case 1 .18
6.4.3 Example case 2 .19
6.4.4 Example case 3 .19
6.4.5 Example case 4 .20
6.4.6 Example case 5 .21
6.4.7 Example case 6 .22
7 Calculated energy performance of buildings .22
7.1 Output data .22
7.2 Calculation intervals and calculation period . .22
7.2.1 Calculation interval .22
7.2.2 Calculation period . .25
7.3 Input data .25
7.3.1 Product data . .25
7.3.2 System design data . . .25
7.3.3 Operating conditions .25
7.3.4 Constants and physical data.27
7.3.5 Other data .27
7.4 Description of the calculation procedure .28
8 Measured overall energy performance and comparison with calculations .28
8.1 General .28
8.2 Output of the method .29
8.3 Measurement intervals and measurement period .29
8.4 Input data .30
8.4.1 Product data . .30
8.4.2 System design data . . .30
8.4.3 Operating conditions data .30
8.4.4 Constants and physical data.31
8.4.5 Other data .31
8.5 Measurement procedures.31
8.6 Calculation of the energy performance based on measured energy .31
8.7 Comparison between calculated energy performance and measured
energy performance .31
8.8 Measured energy performance reporting .32
9 Overall assessment of the energy performance of buildings .32
9.1 Categorization of building and/or spaces .32
9.2 Combination of building services included in EPB in each space .32
9.3 Useful floor area and air volume .32
9.4 Normalization to building size .33
9.4.1 Reference size .33
9.4.2 Normalization . .35
9.4.3 Reference floor area .35
9.5 Assessment boundary and perimeters .35
9.5.1 General principles .35
9.5.2 Assessment boundary for multiple buildings .36
9.6 Overall energy performance .36
9.6.1 Weighted overall energy balance .36
9.6.2 Primary energy factors .37
9.6.3 Greenhouse gas emission factors .39
9.6.4 Additional weighting factors .39
9.6.5 Costs factors .39
9.6.6 Weighting factors for exported energy .39
9.6.7 Energy flows .42
9.7 Share of renewable energy .43
9.7.1 General.43
9.7.2 Amount of primary energy from renewable source E .
P;ren 43
9.7.3 Amount of total primary energy E .
Ptot 43
9.7.4 Examples of RER calculation .43
9.8 Energy performance indicators for technical building systems .45
9.9 Calculation methods for energy performance indicators per part of a building
and/or service .45
10 Zoning .46
10.1 General .46
10.2 Thermal zones and service areas .48
10.3 Spaces .48
10.4 Zoning rules .50
10.4.1 Principle .50
10.4.2 Specific zoning criteria .51
10.5 Assignment rules .52
10.5.1 Subdivision .52
iv © ISO 2017 – All rights reserved

10.5.2 Recombination .54
10.6 Zoning procedure .55
11 Calculation of the energy performance, routing and energy balance .55
11.1 General .55
11.2 Overall calculation procedure (steps) .55
11.3 Calculation principles of the recovered gains and losses .56
11.4 Effect of building automation and control (BAC) and technical building
management (TBM) .56
11.5 Climatic and external environment data .61
11.6 Overall energy performance .61
11.6.1 General.61
11.6.2 Electricity and other energy carriers with exportation .61
11.6.3 Energy carriers without exportation .72
11.6.4 Exported heat on-site produced and not included in thermal use of
the building . .72
12 Common overarching output – General .73
12.1 General .73
12.2 Tabulated overview of the amounts of energy per energy carrier and energy service .75
12.2.1 Absolute values .75
13 Additional information to the over-arching EPB standard .89
13.1 Worked out examples .89
13.2 Application range .89
13.3 Regulation use .89
13.4 Validation test .90
13.5 Quality issues .90
Annex A (informative) Input and method selection data sheet — Template.91
Annex B (informative) Input and method selection data sheet — Default choices .93
Annex C (informative) Common subscripts .101
Annex D (informative) Calculation of measured energy performance .108
Annex E (informative) Calculation methods for energy performance indicators per part of a
building and/or service .109
Annex F (informative) Alphabetic index of terms .116
Annex G (informative) Electrical grid related indicators .117
Annex H (informative) Proposal of indicators for the assessment of nearly Zero-Energy
Buildings (NZEB) .118
Annex I (informative) Lighting systems.121
Annex J (informative) Calculation examples .123
Annex K (informative) Flow diagram .170
Annex L (informative) List of technologies .174
Bibliography .178
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/TR 52000-2 was prepared by the European Committee for Standardization (CEN) Technical
Committee CEN/TC 371, Energy Performance of Buildings project group, in collaboration with ISO
Technical Committees TC 163, Thermal performance and energy use in the built environment, and TC 205,
Building environment design, in accordance with the Agreement on technical cooperation between ISO
and CEN (Vienna Agreement).
A list of all parts in the ISO 52000 series can be found on the ISO website.
vi © ISO 2017 – All rights reserved

Introduction
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, Energy Performance of Buildings - Basic Principles for the set of EPB
[13]
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-
[14]
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 standard, to demonstrate the
correctness of the EPB calculation procedures.
Each EPB-standards follows the basic principles and the detailed technical rules and relates to the
[1]
overarching EPB-standard, ISO 52000-1 .
One of the main purposes of the revision of the EPB-standards is 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
[14]
contents (see CEN/TS 16629 ):
— to avoid flooding and confusing the actual normative part with informative content,
— to reduce the page count of the actual standard, and
— to facilitate understanding of the set of EPB standards.
[5]
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 the overarching EPB standard (ISO 52000-1) that addresses the
overarching principles for EPB-standards. The overarching EPB standard, contains the common terms,
definitions and overall energy performance assessment procedures, as a basis for a systematic, clear
and comprehensive set of EPB standards. It forms part of a set of standards related to the evaluation of
the energy performance of buildings (EPB).
The role and the positioning of ISO 52000-1 in the set of EPB standards is defined in the Introduction to
the standard.
Accompanying spreadsheets
Spreadsheets are produced through the implementation of ISO 52000-1. These spreadsheets (including
possible updated versions) are available at www .epb .center. In this document, examples of each of these
calculation sheets are included.
1)
Background and history of this document, ISO 52000-1 and the set of EPB standards :
Boosting energy efficiency of buildings
Since buildings burn 40 % of all the energy consumed, designing better buildings and retrofitting existing
ones will help to reduce the energy demand and to create significant job opportunities world-wide.
The building sector has a great potential to reduce the greenhouse gas emissions, in line with the
climate targets set at the Paris climate conference (COP21) in December 2015. Helping to decarbonize
the building sector is the goal of the new holistic approach, the set of EPB standards (ISO 52000-series;
see below under “Road ahead”) being developed for the energy performance of buildings (EPB).
Holistic approach
The set of EPB standards …
take into account and include:
• indoor climate • needs
• thermal properties (of walls, windows, etc.) • use
• heating • calculation
• cooling and air conditioning • measurement
• domestic hot water • inspection
• ventilation • building design
• lighting • new and existing buildings
• (de)humidification • certification/labelling
• building automation and control (BAC/BMS) • simple and complex buildings
• renewable energy sources
Why is the holistic approach important for the energy performance of buildings (EPB) ?
In the past, energy performance requirements were set at component level – minimum thermal
insulation levels and minimum efficiencies of products. This, however, leads to sub-optimal solutions
and creates a barrier to the necessary technology transitions.
The holistic approach to assessing the overall energy performance of buildings and the built
environment, provided by the set of EPB standards, is a key tool to overcome these barriers.
1) The references [26] to [43] (see bibliography) contain more extensive background information on the set of
EPB standards.
viii © ISO 2017 – All rights reserved

The set of EPB standards enable to assess the overall energy performance of a building. This means that
any combination of technologies can be used to reach the intended energy performance level, at the
lowest cost.
Due to this ‘competition’ between different technologies, the holistic approach is a key driver for
technological innovation and change. Countries using the approach for several years – take, for instance,
the Netherlands – have experienced large scale implementation and cost savings on a variety of new
technologies.
And there is the economic benefit: Energy expenditures account for a substantial part of a building’s
total operating costs.
Who are the potential users of the EPB set of standards, and what should they be aware of ?
The energy assessment of buildings is carried out for various purposes, such as:
— judging compliance with building regulations expressed in terms of limited energy use or a related
quantity,
— increasing transparency in real-estate transactions through an energy performance certification
and/or display of the level of energy,
— monitoring the energy efficiency of the building and its technical building systems,
— helping to plan retrofit measures through predicting energy savings that would result from various
actions.
In general, the holistic approach means that the energy performance is assessed as the total energy
used for heating, cooling, lighting, ventilation, domestic hot water, and, in some cases, appliances. It
ensures that all technologies are treated equally and balanced.
With the EPB set of standards:
— Policy makers acquire an instrumentation that enables them to take measures in the built
environment and to quantify how much these measures would reduce the energy consumed in
buildings.
— Building industry, engineers and designers can improve the energy-efficiency of their designs,
building products and systems. The set of standards take these current and future products,
systems and designs into account. Due to the holistic approach the risk of suboptimum solutions at
component level is minimized. This way industry knows in what direction to innovate.
— Building owners and occupants can benchmark against other buildings and predict the energy
saving potential of improvements.
First editions: European standards
The set of standards and accompanying technical reports on the energy performance of buildings have
been prepared under a mandate given to CEN by the European Commission and the European Free
[4]
Trade Association (Mandate M/480 )
Directive 2010/31/EU recasting the Directive 2002/91/EC on energy performance of buildings
[2]
(EPBD ) 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).
[3]
The first mandate to CEN to develop a set of CEN EPBD standards (M/343 ,), to support the first edition
[2]
of the EPBD resulted in the successful publication of all EPBD related CEN standards in 2007-2008.
The mandate M/480 was issued to review the previous 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 & 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.
Road ahead: ISO 52000‑ series
The numbers ISO 52000 through ISO 52150 are reserved for the EPB standards. So in the near future
the term ISO 52000 series of standards will become equivalent to the term EPB set of standards.
Only standards that meet specific requirements, will be awarded such number. Currently, only 15
numbers are issued, mostly general EPB standards, or for building (thermal, solar) calculations. In
2017/2018 some 30 standards might become an ISO 52xxx standard, making use of the work already
done in Europe.
The ISO 52000 series is modular and flexible, making it the perfect basis for future developments like
innovations, new insights and new market demands.
x © ISO 2017 – All rights reserved

TECHNICAL REPORT ISO/TR 52000-2:2017(E)
Energy performance of buildings — Overarching EPB
assessment —
Part 2:
Explanation and justification of ISO 52000-1
1 Scope
[1]
This document refers to the overarching EPB-standard, ISO 52000-1 .
It contains information to support the correct understanding, use and national implementation of
ISO 52000-1. This includes:
— explanation on the procedures and background information and justification of the choices that
have been made;
— reporting on validation of calculation procedures given in the standard;
— explanation for the user and for national standards writers involved with implementation of the set
of EPB standards, including detailed examples.
2 Normative references
There are no normative references in this document.
Some explanations regarding Clause 2 of the overarching EPB standard:
If a reference is made in the text of the standard to a specific part of another standard, only this specific
part is referenced, not the entire other standard.
The following text in ISO 52000-1:2017, Clause 2 “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.” is the
standard phrasing for any ISO standard. As stated in the ISO/IEC Directives, Part 2:2016, Clause 15,
the normative references clause is an informative element that lists, for information, those documents
which are cited normatively in the document. Information on how these references apply is found in
the place where they are cited in the document, and not in the normative references clause. The list of
normative references is therefore given for the convenience of the user, who can then consult the place
where they are cited in the document to understand and assess how they apply.
NOTE 1 EPB is regulated in some countries or regions: regulations do not necessarily endorse the complete
set of EPB standards and might modify the content of the standard(s).
To keep flexibility in referencing standards, the references to EPB standards are placed in the national
choices and input data sheet, see Annex A and Annex B.
The references to EPB standards are given as module code numbers instead of a simple list ([1], [2],.[3]),
because with the EPB module code numbers the same module code numbering can be used for all EPB
standards.
NOTE 2 This will facilitate the making of a consistent set of national annexes for each EPB standard and
contribute to overall consistency and transparency.
3 Terms and definitions
This clause provides an explanation of some of the terms and definitions given in ISO 52000-1. The
numbers in brackets refer to the term-numbers in ISO 52000-1:2017, Clause 3.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1 Buildings
Building (term 3.1.2)
“Building” means the physical construction including the technical building systems.
“Building unit” has been defined separately (term 3.1.8).
The definition in EPBD: “‘building’ means a roofed construction having walls, for which energy is used
to condition the indoor climate” is not usable in this context, e.g. because there are buildings without
walls (only roof), or without roof (e.g. pyramid shaped, only inclined walls).
Building category (term 3.1.3)
The term “category” does not only relate to the type of use: also to size, to the period of use (e.g.
temporary use) and to other qualifications (e.g. historic buildings).
See also the notes and examples in ISO 52000-1:2017 at this entry and at the definition of Space category
(term 3.1.14).
Reference floor area (term 3.1.12)
The reference floor area should not b
...