ISO/FDIS 50002-2

ISO/TC 301/WG 17
Secretariat: ANSI
Date: 2025-02-13
Energy audits —
Part 2:
Guidance for conducting an energy audit using ISO 50002-1 in
buildings
FDIS stage
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
E-mail: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles of energy auditing . 2
5 Performing an energy audit . 2
5.1 General . 2
5.2 Planning . 3
5.3 Opening meeting . 5
5.4 Data collection . 6
5.5 Measurement plan . 8
5.6 Site visit . 9
5.7 Analysis . 10
5.8 Reporting . 13
5.9 Closing meeting . 15
6 Competence of the energy auditor. 15
Annex A (informative) Data which can be collected . 17
Bibliography . 23

iii
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 301, Energy management and energy savings.
This first edition, along with ISO 50002-1 and ISO 50002-3, cancels and replaces the first edition ISO
50002:2014.
A list of all parts in the ISO 50002 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
Introduction
An energy audit can help an organization to identify opportunities to improve energy efficiency. It can be part
of a site-wide energy management system (EnMS). Energy audits in buildings can help to achieve
improvements such as:
— energy conservation;
— energy efficiency;
— improved occupant comfort, health and well-being;
— sustainability goals and targets; and
— climate resilience.
The benefits to the organization maycan include:
— reduced energy and operating costs;
— improved information for asset management;
— wiser investment strategy based on energy audit results; and
— meeting organizational goals related to greenhouse gas (GHG), emissions reduction net zero, materials
use, productivity and occupant satisfaction.
The use and operation of buildings requires the provision of services such as heating, cooling, ventilation,
lighting, domestic hot water, transportation systems (e.g. elevators, escalators, moving walkways) in
buildings, information systems and processes. In addition, the operation of buildings typically involves other
energy end uses such as appliances or plug loads within the building.
A building's energy consumption depends on:
— local climate conditions;
— the characteristics of the building envelope;
— the age and typology of the building(s)
— the designed indoor environment conditions;
— the characteristics and settings of the technical building systems;
— activities and processes in the building; and
— occupant behaviour and operational regime.
When dealing with buildings, the audited objects are sometimes similar, technically simple and numerous (e.g.
in the residential sector), but can also be unique, complex and highly technical (such as hospitals, swimming
pools and spas, etc.).
Energy audits in buildings may include the whole building, parts of the building or some particular technical
system.
v
Energy performance indicators (benchmark values, if available) or average statistical specific energy
consumption data are usually published nationally for different building types and ages. This information can
be used in the analysis to provide comparative energy performance evaluation. Where this information is not
available, comparable data can be found for similar climates through international sources [(e.g. Thethe
International Energy Agency (IEA)].)).
NOTE The energy audits covered by this document can be independent from building energy performance
certification.
Energy audits and energy saving opportunities identified in energy audits are best implemented in the context
of an EnMS, such as one consistent with ISO 50001. Whether or not an organization has an EnMS in place,
organizations are more likely to achieve the intended outcomes of an energy audit when their top
management supports the audit objective(s) and agrees to provide sufficient resources for the audit process
and post-audit activities.
In this document, the following verbal forms are used:
• “shall” indicates a requirement;
• should” indicates a recommendation;
• “may” indicates a permission;
• “can” indicates a possibility or a capacity.
vi
Energy audits —
Part 2:
Guidance for conducting an energy audit using ISO 50002-1 in
buildings
1 Scope
This document gives guidance on how to apply ISO 50002-1 to carry out energy audits of a building or group
of buildings (new or existing). It is intended to be used in conjunction with, and is supplementary to, ISO
50002-1.
This document does not apply to other areas such as process audits (see ISO 50002-3), specific energy systems
(e.g. compressed air) or transport.
This document is applicable to buildings and can be used independently or in conjunction with ISO 50002-3.
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 50002-1, Energy audits — Part 1: General requirements with guidance for use
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 50002-1 and the following apply.
ISO and IEC maintain terminologicalterminology 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
building
construction as a whole, including its envelope and all technical building systems (3.5(3.4),), for which energy
can be used to condition the indoor climate, and to provide domestic hot water, illumination and other services
related to the use of the building and the activities performed within the building
Note 1 to entry: The term can refer to the building as a whole or to parts thereof that have been designed or altered to be
used separately.
Note 2 to entry: The building can include its site location and related external environment.
Note 3 to entry: Processes within the building (e.g. chilling of food in supermarkets) are addressed in ISO 50002-3. To
the extent that the energy use of such processes affects, or is affected by, the building, they can be included in the scope
of the energy audit process described in this document.
3.2
building envelope
elements of a building (3.1) that enclose conditioned spaces through which thermal energy can be transferred
to or from the exterior, or to or from unconditioned spaces
3.3
building fabric
all physical elements of a building (3.1), excluding technical building systems (3.5(3.4))
EXAMPLE Roofs, walls, floors, doors, gates and internal partitions.
Note 1 to entry: It includes elements both inside and outside of the thermal envelope, including the thermal envelope
itself.
Note 2 to entry: The fabric determines the thermal transmission, the thermal envelope airtightness and (nearly all of) the
thermal mass of the building (apart from the thermal mass of furniture and technical building systems). The fabric also
makes the building wind and water tight. The building fabric is sometimes described as the building as such, i.e. the
building without any technical building system.
[SOURCE: ISO 52000-1:2017, 3.1.5]
3.4
building servicesservice
servicesservice provided by the technical building systems (3.5(3.4)) and by appliances to condition the indoor
environment (thermal comfort, air quality, visual and acoustic quality) and other services related to the use
of the building (3.1) (such as escalators/elevators)
3.5
technical building system
technical equipment for heating, cooling, ventilation, humidification, dehumidification, domestic hot water,
lighting, information systems including building automation and control, and on-site energy production
Note 1 to entry: A technical building system can refer to one or to several building services (3.4(3.3)) (e.g. heating system
includeincluding heating, domestic hot water system and controls).
Note 2 to entry: A technical building system is composed of different subsystems and includes controls.
Note 3 to entry: Electricity and thermal energy production can include cogeneration, wind power, photovoltaic systems,
district energy, heat pumps and other renewable energy sources, within the agreed scope of the energy audit.
Note 4 to entry: ISO 52000-1 provides definitions of specific technical building systems.
[SOURCE: ISO 520
...