ISO 16346:2013

Energy performance of buildings - Assessment of overall energy performance

ISO 16346:2013 defines the general procedures to assess the energy performance of buildings, including technical building systems, and defines the different types of ratings, and the building boundaries. The purpose of ISO 16346:2013 is to a) collate results from other International Standards that calculate energy use for specific services within a building, b) account for energy generated in the building, some of which may be exported for use elsewhere, c) present a summary of the overall energy use of the building in tabular form, d) provide energy ratings based on primary energy, carbon dioxide emission, or other parameters defined by a national energy policy, and e) establish general principles for the calculation of primary energy factors and carbon dioxide emission coefficients. ISO 16346:2013 defines the energy services to be taken into account for setting energy performance ratings for planned and existing buildings and provides for 1) a method to compute the standard calculated energy rating, a standard energy use that does not depend on occupant behaviour, actual weather, and other actual (environment or indoor) conditions, 2) a method to assess the measured energy rating, based on the delivered and exported energy, 3) a method to improve confidence in the building calculation model by comparison with actual energy use, and 4) a method to assess the energy effectiveness of possible improvements. ISO 16346:2013 is applicable to a part of a building (e.g. flat), a whole building, or several buildings.

Performance énergétique des bâtiments — Evaluation de la performance énergétique globale

General Information

• Status: Withdrawn
• Publication Date: 22-Sep-2013
• Withdrawal Date: 22-Sep-2013
• 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: 9599 - Withdrawal of International Standard
• Start Date: 21-Jun-2017
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO 52000-1:2017 - Energy performance of buildings - Overarching EPB assessment - Part 1: General framework and procedures
• Effective Date: 14-Nov-2015

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 16346
First edition
2013-10-01
Energy performance of buildings —
Assessment of overall energy
performance
Performance énergétique des bâtiments — Evaluation de la
performance énergétique globale
Reference number
©
ISO 2013
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO 2013 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 2
5 Assessment of energy performance of buildings. 2
5.1 Energy uses . 2
5.2 Assessment boundaries . 3
5.3 Types and uses of ratings . 6
6 Weighted energy ratings . 6
6.1 Types of ratings and indicators used . 6
6.2 Types of factors or coefficients . 7
6.3 Energy use indicator . 8
6.4 Primary energy rating . 8
6.5 Carbon dioxide rating .12
6.6 Policy energy rating .13
7 Calculated energy rating .13
7.1 Calculation procedure .13
7.2 Set of formulae .15
7.3 Building thermal needs .21
7.4 Technical building systems .22
8 Measured energy rating .26
8.1 General requirements .26
8.2 Assessment period .26
8.3 Assessing the used amounts of all energy carriers.29
8.4 Correction for weather .30
9 Validated building calculation model .31
9.1 Introduction .31
9.2 Procedure — Validation of the building calculation model .31
9.3 Climatic data .31
9.4 Occupancy data .32
9.5 Ratings based on the validated calculation model .33
10 Planning retrofit measures for existing buildings .33
11 Test report .34
12 Standard operating assumptions .36
12.1 Introduction .36
12.2 Input data .36
Annex A (normative) Parallel routes in normative references .38
Annex B (informative) Methods for collecting building data .39
Annex C (informative) Energy monitoring .43
Annex D (informative) Other uses of energy .46
Annex E (informative) Calorific values of fuels .48
Annex F (informative) Confidence intervals .51
Annex G (informative) Example .55
Bibliography .62
iv © ISO 2013 – All rights reserved

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 meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 163, Thermal performance and energy use in the
built environment, in collaboration with Technical Committee ISO/TC 205, Building environment design.
Introduction
This International Standard is prepared by ISO/TC 163, Thermal performance and energy use in the built
environment, in collaboration with Technical Committee ISO/TC 205, Building environment design and is
one of three closely linked documents dealing with definitions and general procedures for the overall
building energy performance rating and certification (see also Figure 1):
— ISO/TR 16344, Energy performance of buildings — Common terms, definitions and symbols for the
overall energy performance rating and certification;
— ISO 16343: Energy performance of buildings — Methods for expressing energy performance and for
energy certification of buildings;
— ISO 16346: Energy performance of buildings — Assessment of the overall energy performance.
ISO/TR 16344 provides a coherent set of terms, definitions, and symbols for concepts and physical
quantities related to the overall energy performance of buildings and its components, including
definitions of system boundaries, to be used in all International Standards elaborated within ISO on
energy performance of buildings.
ISO 16343 sets out ways of expressing the energy performance in an energy performance certificate
of a building (including the technical building systems) and ways of expressing requirements as to the
energy performance. This includes an overall numerical energy performance indicator and classes
against benchmarks.
Their development greatly benefited from similar CEN documents (viz. CEN/TR 15615, EN 15217, and
EN 15603) developed to support the European Energy Performance of Buildings Directive (EPBD).
A revision of the set of CEN standards to support the EPBD is anticipated in the near future. Issuing the
ISO documents aims to bring the key subjects of building energy performance assessment to the global
international level.
Given the strong demand for these International Standards at ISO level, it was decided not to delay
the advancement of these International Standards and Technical Report by waiting on these CEN
developments. However, it is expected that a future revision of these International Standards and
Technical Report will be carried out in collaboration with CEN under the Vienna Agreement.
vi © ISO 2013 – All rights reserved

Common terms, deinitions and symbols
Energy Performance (EP)
ISO TR 16344
EP
Overall Energy
Performance of the
EP
ISO 16343
building including its
expressions
technical building
ISO 16346
systems
EP aggregation
Boundaries, classi
ication
Collect all energy elements
Building energy needs
and system energy losses
Component input data
Boundary conditions
Figure 1 — Flow diagram illustrating the successive elements of the general procedures
Introduction to the assessment of overall energy performance
Energy assessments of buildings are carried out for various purposes, such as:
a) judging compliance with building regulations expressed in terms of a limitation on energy use or a
related quantity;
b) checking for transparency in commercial operations through the energy certification and/or display
of a level of energy performance (energy performance certification);
c) monitoring of the energy efficiency of the building and its technical building systems;
d) helping in planning retrofit measures through prediction of energy savings which would result
from various actions.
This International Standard specifies a general framework for the assessment of overall energy use of a
building and the calculation of energy ratings in terms of primary energy, CO emissions, or parameters
defined by a national energy policy. Separate standards calculate the energy use of services within a
building (heating, cooling, hot water, ventilation, lighting, and transport for people) and produce results
that are used here in combination to show overall energy use. This assessment is not limited to the
building alone, but takes into account the wider environmental impact of the energy supply chain.
An allowance is made for energy that may be generated within or on the surface of the building and
which is used to offset fuel and power drawn from other sources. Energy generated at the building site
and exported is credited, provided it is exported for use elsewhere.
Energy certification of buildings requires a method that is applicable to both new and existing buildings
and which treats them in an equivalent way. Therefore, a method to obtain equivalent results from
different sets of data is presented in this International Standard. A method to assess missing data
and to calculate a standard energy use for space heating and cooling, ventilation, domestic hot water,
and lighting is provided. This International Standard also provides a method to assess the energy
effectiveness of possible improvements.
Two principal types of energy ratings for buildings are proposed in this International Standard:
a) calculated energy rating;
b) measured energy rating.
Because of the differences in the way these two ratings are obtained, they cannot be directly compared.
However, the difference between the two ratings for the same building can be used to assess the
cumulative effects of actual construction, systems, and operating conditions versus standard ones and
the contribution of energy uses not included in the calculated energy rating.
Values for factors and coefficients needed to calculate primary energy and CO emissions related to
energy policy should be defined in a national annex.
NOTE Energy is not produced, but only transformed. However, in this International Standard, energy is used
in one form by systems that generate other forms of energy. At its final stage in the building, energy is used to
provide services such as heating, cooling, ventilation, hot water, lighting.
viii © ISO 2013 – All rights reserved

INTERNATIONAL STANDARD ISO 16346:2013(E)
Energy performance of buildings — Assessment of overall
energy performance
1 Scope
This International Standard defines the general procedures to assess the energy performance of
buildings, including technical building systems, and defines the different types of ratings, and the
building boundaries.
The purpose of this International Standard is to
a) collate results from other International Standards that calculate energy use for specific services
within a building,
b) account for energy generated in the building, some of which may be exported for use elsewhere,
c) present a summary of the overall energy use of the building in tabular form,
d) provide energy ratings based on primary energy, carbon dioxide emission, or other parameters
defined by a national energy policy, and
e) establish general principles for the calculation of primary energy factors and carbon dioxide
emission coefficients.
This International Standard defines the energy services to be taken into account for setting energy
performance ratings for planned and existing buildings and provides for
1) a method to compute the standard calculated energy rating, a standard energy use that does not
depend on occupant behaviour, actual weather, and other actual (environment or indoor) conditions,
2) a method to assess the measured energy rating, based on the delivered and exported energy,
3) a method to improve confidence in the building calculation model by comparison with actual
energy use, and
4) a method to assess the energy effectiveness of possible improvements.
This International Standard is applicable to a part of a building (e.g. flat), a whole building, or several buildings.
It is up to national bodies to define under which conditions, for which purposes, and for which types of
buildings the various ratings apply.
This International Standard handles the energy performance of a building as a whole. The assessment
of the energy performance of specific technical building systems is handled in the appropriate part of
the EN 15241, EN 15243, and EN 15316 series or the appropriate International Standards or national
standards as listed in Annex A.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 7345:1995, Thermal insulation — Physical quantities and definitions
ISO 12569, Thermal performance of buildings and materials — Determination of specific airflow rate in
buildings — Tracer gas dilution method
ISO 13789, Thermal performance of buildings — Transmission and ventilation heat transfer coefficients —
Calculation method
ISO 13790, Energy performance of buildings — Calculation of energy use for space heating and cooling
ISO 14025, Environmental labels and declarations — Type III environmental declarations — Principles
and procedures
ISO 16343, Energy performance of buildings — Methods for expressing energy performance and for energy
certification of buildings
ISO 16818, Building environment design — Energy efficiency — Terminology
ISO/TR 16344, Energy performance of buildings — Common terms, definitions and symbols for the overall
energy performance rating and certification
EN 15193:2007, Energy performance of buildings — Energy requirements for lighting
EN 15232:2007, Energy performance of buildings — Impact of Building Automation, Controls and
Building Management
EN 15241, Ventilation for buildings — Calculation methods for energy losses due to ventilation and
infiltration in commercial buildings
EN 15243, Ventilation for buildings — Calculation of room temperatures and of load and energy for buildings
with room conditioning systems
EN 15316 (all parts), Heating systems in buildings — Method for calculation of system energy requirements
and system efficiencies
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345 and ISO/TR 16344 apply.
NOTE These terms and definitions are applicable to energy calculations according to this International
Standard and to International Standards that are based on this one, to provide input to or use output from this
International Standard.
4 Symbols and abbreviated terms
The International Standards dealing with the energy performance of buildings introduce a large number
of quantities and their associated symbols.
To facilitate the use of the International Standards, a common set of symbols and subscripts has been
defined, as given in ISO/TR 16344 (Terms, definitions, and symbols). The symbols follow established
standards of nomenclature, such as ISO 7345, and introduce others that are common to the set of
International Standards needed to assess the energy performance of buildings, in particular a set of
subscripts to distinguish between different energy uses, different energy carriers, etc.
The symbols given in ISO/TR 16344 concern only data passed from one International Standard (or part
of an International Standard) to another.
5 Assessment of energy performance of buildings
5.1 Energy uses
The assessment of the annual energy used by a building shall comprise the following services:
— heating;
2 © ISO 2013 – All rights reserved

— cooling and dehumidification;
— ventilation and humidification;
— hot water;
— lighting (optional for residential buildings);
— transport for people (optional);
— other services (optional).
The annual energy use includes auxiliary energy and losses of all systems.
National bodies decide if energy for lighting in residential buildings, as well as energy for transport
for people and other services (e.g. electrical appliances, cooking, industrial processes) in all types of
buildings shall be included or not in the calculated rating.
NOTE Energy uses for lighting and other services are included in the measured energy rating.
5.2 Assessment boundaries
The boundary for the energy performance assessment shall be clearly defined before the assessment. It
is called system boundary. The system boundary is related to the rated object (e.g. flat, building).
Inside the system boundary, the system losses are taken into account explicitly; outside the system
boundary, they are taken into account in the conversion factor.
Energy can be imported or exported through the system boundary. Some of these energy flows can be
quantified by meters (e.g. gas, electricity, district heating, and water). The system boundary for energy
carriers is the meters for gas, electricity, district heating, and water, the loading port of the storage
facility for liquid, and solid energy carriers.
Consequently, if a part of a technical building system (e.g. boiler, chiller, cooling tower, etc.) is located
outside the building envelope but forms part of the building services assessed, it is considered to be
inside the system boundary and its system losses are therefore taken into account explicitly.
Key
1 user
2 emission
3 distribution
4 storage
5 boiler
6 fuel
7 electricity
8 auxiliary energy
9 thermal solar collector
10 photovoltaic panels
11 boundary
Figure 2 — Boundary — Examples of energy flows across the system boundary
The following two figures illustrate the energy flows inside and across the system boundary.
NOTE 1 These illustrations are more complete than Figure 2.
4 © ISO 2013 – All rights reserved

NOTE 2 Part of the recoverable heat or cold from the systems may be recovered in the building, thus reducing
or augmenting the building energy needs for heating and/or cooling.
Figure 3 — Boundary and energy flows — Main energy flows within and crossing the boundaries
Figure 4 — Boundary and energy flows — More detailed view on the energy flows for produced,
used, and exported electricity at and from the building site
For active solar, wind, or water energy systems, the incident solar radiation on solar panels or the kinetic
energy of wind or water is not part of the energy balance of the building. Only the energy delivered by
the generation devices and the auxiliary energy needed to supply the energy from the source (e.g. solar
collector) to the building are taken into account in the energy balance. It is decided on the national level
whether this energy is part or not of the delivered energy.
The assessment can be made for a group of buildings if they are on the same lot or are serviced by the
same technical systems.
Specific rules for the boundaries, depending on the purpose of the energy performance assessment and
the type of the buildings, may be provided at national level.
5.3 Types and uses of ratings
This Internatonal Standard gives two principal options for energy rating of buildings:
— calculated energy rating;
— measured energy rating.
The calculated energy rating includes energy use for heating, cooling, ventilation, hot water, and when
appropriate, fixed built-in lighting. It does not include energy for other services unless so decided at national
level. Therefore, both ratings cannot be compared without special caution, as mentioned in Clause 8.
The calculated energy rating can be either:
— standard, based on conventional climate, use, surroundings, and occupant-related input data
defined at national level and given in a national annex. This rating is called “design rating” when
applied to a planned building;
— tailored, calculated with climate, occupancy, and surroundings data adapted to the actual building
and the purpose of the calculation.
The assessment method of the measured energy rating is given in Clause 8.
National bodies determine
— which type of rating applies for each building type and purpose of the energy performance assessment,
— under what conditions the design rating can be considered as or converted to a calculated energy
rating for the actually realized building, and
— if renewable energy produced on site is part or not of delivered energy.
The types of rating are summarized in Table 1.
Table 1 — Types of ratings
Name Input data Utility or purpose
Use Climate Building
Calculated Design Standard Standard Design Building permit, certificate under conditions
Standard Standard Standard Actual Energy performance certificate, regulation
Tailored Depending on purpose Actual Optimization, validation, retrofit planning
Measured Operational Actual Actual Actual Energy performance certificate, regulation
6 Weighted energy ratings
6.1 Types of ratings and indicators used
NOTE 1 Annex G contains a worked example of the procedures in this clause.
6 © ISO 2013 – All rights reserved

NOTE 2 ISO 16343 describes different levels of ratings, from integrated building energy performance to energy
performance at component level. So it is to be discussed if the performance ratings of the envelope and of systems
would not be better placed in ISO 16343.
ISO/FDIS 23045 presents a list of indicators for the different aspects of the energy efficiency of buildings,
as in the following:
— performance of the building envelope;
— performance of the building envelope including the building technical systems;
— performance of technical building systems;
— performance of the building expressed in terms of primary energy use;
— performance of the building expressed in terms of related CO .
The indicators may be expressed as an absolute value that gives information about the global performance
of the building or a relative value that allows comparison between the buildings and/or the technical
building systems of the same category. As energy required and, consequently, energy delivered are closely
related to designed comfort, indoor design conditions shall also be given at project definition stage.
Area (or volume) considered for the expression of efficiency and performance factors is the heated
and/or cooled area as defined in ISO 16818. If not applicable, the definition of the floor area shall be
defined as most factors can be related to this area.
A building usually uses more than one energy carrier. Therefore, a common expression of all energy
carriers shall be used to aggregate the used amounts, sometimes expressed in various units and always
having various impacts.
According to this International Standard, the aggregation methods are based on the following impacts
the use of energy have:
— primary energy;
— carbon dioxide emission;
— parameters defined by national energy policy.
NOTE 3 Cost is a parameter that may be used in the energy policy aggregation method.
6.2 Types of factors or coefficients
6.2.1 General
The aggregation needs factors and coefficients determined at a national level according to the rules
given below. Values for factors needed to calculate the primary energy and/or CO emissions should be
defined in a national annex.
NOTE 6.4.2 provides factors which can be used if no national values are given.
In a multi-plant generation system (e.g. electricity, district heating), the weighting factor at any time
depends on which generation plants operate continuously and which plants are affected by a change
in energy demand. A distinction between average, marginal, and end-use factors or coefficients may
therefore be appropriate for the aggregation.
6.2.2 Average factor or coefficient
The average factor or coefficient reflects the annual average impact of all plants delivering energy
(directly or indirectly) to the building. It is calculated by estimating the total impact (primary energy
use, CO production) during a year and divided by the total energy delivered.
6.2.3 Marginal factor or coefficient
If energy use or production is reduced (or increased), not all power stations are affected equally: the
operation of “base load” stations is unchanged. A decrease in demand is met by reduced operation of
other plants. Exported energy by a building reduces the need for a new plant.
The marginal factor or coefficient takes into account only production units that are affected by such
changes in energy demand or production. For example, the marginal new plant factor or coefficient
relates to a new plant that should be built if the energy demand increases or that is saved due to exported
electricity produced at the building sites.
6.2.4 End-use factor or coefficient
Different services (e.g. lighting, heating, air-conditioning) produce demands at different times, each
having very different demand patterns that may justify the use of specific demand-weighted factors for
different end uses.
6.2.5 Use of environmental declaration
The environmental declaration, as defined in ISO 14025, is based on the Life Cycle Assessment (LCA)
Methodology. Information about use of energy resource and CO can be used as a basis to express the
useful indicator related to primary energy or CO .
6.3 Energy use indicator
6.3.1 General
The energy use indicator represents the performance of the building envelope. This indicator does not
take into account the performance of the technical building systems. It may be used to consider the
intrinsic ability of the building as the lifetime of the building may exceed the lifetime of the component
of the technical building systems.
6.3.2 Energy use indicator
This indicator is calculated from the energy use for heating, cooling, and lighting including solar and
internal gains but no heat recovery by technical systems.
EQ=
Di∑
(1)
where
Q is the energy needed for any purpose, as defined in 5.1.
i
NOTE Recovered losses are not taken into account as they are related to the definition of the technical
building systems.
For comparison purposes, this indicator can be used as an absolute value (MJ or kWh) or as a relative
value compared to the surface unit of the energy use for the building.
6.4 Primary energy rating
6.4.1 General
The primary energy approach makes possible the simple addition from different types of energies (e.g.
thermal and electrical) because primary energy includes the losses of the whole energy chain, including
8 © ISO 2013 – All rights reserved

those located outside the building system boundary. These losses (and possible gains) are included in a
primary energy factor.
EXAMPLE If building A exports heat to building B, which is located outside the assessment boundaries, this
heat is taken into account in the same way as district heating. The primary energy factor used for building B
includes the system losses (generation, heat losses between building A and B, etc).
6.4.2 ISO weighted energy use
Primary energy factors vary in the world. Nevertheless, for an international comparison of the energy
performance of buildings, a common “ISO” energy performance indicator may be used. In this case, the
information given in Table 2 shall be used.
NOTE 1 Because of different primary energy factors, different climate conditions, and different operation
assumptions, international comparisons are often difficult and can mislead. The design of a building should follow
the concrete conditions and not average international values.
The ISO weighted energy use, E , is calculated from the delivered and exported energy for each
ISO
energy carrier:
EE=− E
ISOI∑∑SO;del;Ici SO;exp;ci
ci ci
(2)
with
EE=×f
ISO;del;ci EPdel,cIiiSO,del,c
(3)
EE=×f
ISO;exp;ci exp,cIiiSO,exp,c
(4)
where
E is the annual ISO weighted energy use for all energy uses included in the energy perfor-
ISO
mance assessment, in MJ or kWh;
E is the annual delivered energy in ISO weighted energy units, for energy carrier ci, in MJ
ISO;del;ci
or kWh, determined according to Formula (3);
E is the annual exported energy in ISO weighted energy units, for energy carrier ci, in MJ
ISO;exp;ci
or kWh, determined according to Formula (4);
E is the annual delivered energy, for energy carrier ci, for all energy uses included in the
EPdel;ci
energy performance assessment, in MJ or kWh, determined according to Formula (10);
E is the annual exported energy, for energy carrier ci, in MJ or kWh, determined according
exp;ci
to Formula (17) for electricity and Formula (18) for thermal energy;
f is the ISO factor for the delivered energy carrier ci, to be determined according to Table
ISO,del,ci
2;
f is the ISO factor for the exported energy carrier ci, to be determined according to
ISO,exp,ci
Table 2.
Table 2 — Conversion factors for ISO weighted energy use f and f
ISO,del,ci ISO,exp,ci
Total energy factor Non-renewable energy factor
Fossil fuels 1,2 1,2
Electricity 3,0 2,5
Log 1,1 0,1
Liquid biomass and biogas 1,5 0,5
NOTE 2 For Table 2, the results of an inventory of national primary energy conversion factors have been used.
6.4.3 Primary energy
The annual primary energy use, E , is calculated from the delivered and exported energy for each
P
energy carrier:
EE=− E
PP∑∑;del;Pci ;exp;ci
ci ci
(5)
with
EE=×f
P;del;ci EPdel,cPii,del,c
(6)
EE=×f
P;exp;ci exp,cPii,exp,c
(7)
where
E is the annual primary energy use for all energy uses included in the energy performance
P
assessment, in MJ or kWh;
E is the annual delivered energy in primary energy units, for energy carrier ci, in MJ or
P;del;ci
kWh, determined according to Formula (6);
E is the annual exported energy in primary energy units, for energy carrier ci, in MJ or
P;exp;ci
kWh, determined according to Formula (7);
E is the annual delivered energy, for energy carrier ci, for all energy uses included in the
EPdel;ci
energy performance assessment, in MJ or kWh, determined according to Formula (10);
E is the annual exported energy, for energy carrier ci, in MJ or kWh, determined according
exp;ci
to Formula (17) for electricity and Formula (18) for thermal energy;
f is the primary energy factor for the delivered energy carrier ci, to be determined accord-
P,del,ci
ing to 6.2;
f is the primary energy factor for the exported energy carrier ci, to be determined accord-
P,exp,ci
ing to 6.2.
These two factors, f and f , can be the same.
P,del,ci P,exp,ci
Table 2 is used for the primary energy calculations. The energy used for different purposes and by
different fuels is recorded separately.
10 © ISO 2013 – All rights reserved

6.4.4 Primary energy factors
There are two conventions for defining primary energy factors.
a) Total primary energy factor: The conversion factors represent all the energy overheads of delivery
to the point of use (e.g. production outside the building system boundary, transport, extraction). In
this case, the primary energy conversion factor always exceeds unity.
b) Non-renewable primary energy factor: The conversion factors represent the energy overheads of
delivery to the point of use but exclude the renewable energy component of primary energy, which
may lead to a primary energy conversion factor less than unity for renewable energy sources.
The primary energy factors shall include at least
— energy to extract the primary energy carrier,
— energy to transport the energy carrier from the production site to the utilization site, and
— energy used for processing, storage, generation, transmission, distribution, and any other operations
necessary for delivery to the building in which the delivered energy is used.
The primary energy factors may also include
— energy to build the transformation units,
— energy to build the transportation system, and
— energy to clean up or dispose the wastes.
National annexes giving tables of values representing local conditions for electricity generation and fuel
supply may be added to this International Standard. Such tables shall give values for primary energy
factors or non-renewable primary energy factors, depending on which are to be used at national level.
Examples of such factors are given in Annex B.
Any national annex that defines primary energy factors and non-renewable primary energy factors
shall state which of the above overheads have been included (e.g. energy to build the transformation and
transportation system). If the coefficients for fuels are given by energy unit, they shall be based on gross
calorific values. In the national annex, it shall also be clearly stated which type of factor or coefficient
defined in 6.2 is used.
6.5 Carbon dioxide rating
6.5.1 Carbon dioxide emissions
The emitted mass of CO is calculated from the delivered and exported energy for each energy carrier:
mE=×()kE−×()k
CO ∑∑del,ceidel,eci xp,cicxp, i
(8)
where
E is the delivered energy for energy carrier ci, according to 7.2;
del,ci
E is the exported energy for energy carrier ci, according to 7.2;
exp,ci
k is the CO emission coefficient for delivered energy carrier ci, to be determined according
del,ci 2
to 6.2;
k is the CO emission coefficient for exported energy carrier ci, to be determined according
exp,ci 2
to 6.2.
The two coefficients K and K can be the same.
del,ci exp,ci
The CO emission calculation shall be reported in accordance with Table 3.
Table 3 — Calculation of ratings (example: CO rating)
Row C1 C2 C3
Delivered energy
Energy carrier 1 Energy carrier i
1 Energy delivered (unweighted) E E
del,1 del,i
2 Weighting factor or coefficient k k
del,1 del,i
3 Weighted delivered energy or CO m m
m
2 CO ,,del1 CO ,,del i
å CO ,,del i
2 2
Exported energy
thermal electrical
4 Energy exported (unweighted) Q E
exp,T exp,el
5 Weighting factor k k
exp,T exp,el
6 Weighted exported energy or CO m m
m
2 CO ,,expT CO ,,expel
å CO ,,exp i
2 2
m
7 Rating
CO
6.5.2 CO emission coefficients
The CO emission coefficients shall include all CO emissions associated with the primary energy used by
2 2
the building, as defined in 6.4. It shall be defined at national level whether the CO emission coefficients
also include the equivalent emissions of other greenhouse gas emissions, e.g. methane.
Any national annex that defines CO emission coefficients shall state which of the additional overheads
mentioned in 6.2 have been included. If the coefficients for fuels are given by energy unit, they shall be
based on gross calorific values. This annex shall also state which type of coefficient defined in 6.2 is used.
12 © ISO 2013 – All rights reserved

6.6 Policy energy rating
In order to influence the energy behaviour of citizens, policy factors can be used to favour or penalize
some energy carriers. The policy energy rating is calculated from the delivered and exported energy for
each energy carrier:
EE=×fE−×f
() ()
pold∑∑el,ciipol,del,cexp,ciipol,exp,c
(9)
where
E is the delivered energy for energy carrier ci, according to 7.2;
del,ci
E is the exported energy for energy carrier ci, according to 7.2;
exp,ci
f is the policy factor for delivered energy carrier ci, to be determined according to 6.2;
pol,del,ci
f is the policy factor for exported energy, to be determined according to 6.2.
pol,exp,ci
7 Calculated energy rating
7.1 Calculation procedure
7.1.1 General
The calculation direction goes from the needs to the source (e.g. from the building energy needs to the
primary energy).
Electrical services (e.g. lighting, ventilation, auxiliary) and thermal services (e.g. heating, cooling,
humidification, dehumidification, domestic hot water) are considered separately inside the building
boundaries.
The building’s on-site energy production based on locally available renewable resources and the
delivered ene
...