ISO 16745-1:2017

Sustainability in buildings and civil engineering works — Carbon metric of an existing building during use stage — Part 1: Calculation, reporting and communication

ISO 16745-1:2017 provides requirements for determining and reporting a carbon metric of an existing building, associated with the operation of the building. It sets out methods for the calculation, reporting and communication of a set of carbon metrics for GHG emissions arising from the measured energy use during the operation of an existing building, the measured user-related energy use, and other relevant GHG emissions and removals. These carbon metrics are separated into three measures designated CM1, CM2, and CM3 (see 5.1.1). ISO 16745-1:2017 follows the principles set out in ISO 15392 and those described in Clause 4. Where deviations from the principles in ISO 15392 occur, or where more specific principles are stated, this document takes precedence. The carbon metrics CM1 and CM2 are not quantified based on life cycle assessment (LCA) methodology. Carbon metric CM3 may include partial quantification based on the results of LCA. ISO 16745-1:2017 does not include any method of modelling of the operational energy use of the building but follows the conventions provided by other International Standards, as given in relevant clauses. ISO 16745-1:2017 is not an assessment method for evaluating the overall environmental performance of a building or a building-rating tool and does not include value-based interpretation of the carbon metric(s) through weightings or benchmarking. ISO 16745-1:2017 deals with the application of the carbon metric(s) for an existing building, either residential or commercial, or a building complex. It does not include provisions for regional and/or national building stock.

Développement durable dans les bâtiments et les ouvrages de génie civil — Métrique du carbone des bâtiments existants pendant la phase opérationnelle — Partie 1: Calculs, rapports et communication

General Information

• Status: Published
• Publication Date: 16-May-2017
• ICS: 91.040.01 - Buildings in general
• Technical Committee: ISO/TC 59/SC 17 - Sustainability in buildings and civil engineering works
• Drafting Committee: ISO/TC 59/SC 17/WG 4 - Environmental performance of buildings
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 14-Sep-2022

Relations

• Revises: ISO 16745:2015 - Environmental performance of buildings — Carbon metric of a building — Use stage
• Effective Date: 05-Nov-2015

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 16745-1
First edition
2017-05
Sustainability in buildings and civil
engineering works — Carbon metric of
an existing building during use stage —
Part 1:
Calculation, reporting and
communication
Développement durable dans les bâtiments et les ouvrages de génie
civil — Métrique du carbone des bâtiments existants pendant la phase
opérationnelle —
Partie 1: Calculs, rapports et communication
Reference number
ISO 16745-1:2017(E)
©
ISO 2017

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ISO 16745-1:2017(E)

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© ISO 2017, Published in Switzerland
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ISO 16745-1:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principles . 5
4.1 General . 5
4.2 Completeness . 5
4.3 Consistency . 5
4.4 Relevance . 6
4.5 Coherence . 6
4.6 Accuracy . 6
4.7 Transparency . 6
4.8 Avoidance of double counting . 6
5 Protocol of measuring the carbon metric of a building in the use stage .6
5.1 System boundary . 6
5.1.1 Types of carbon metrics of a building . 6
5.1.2 System boundary for the carbon metrics of a building . 7
5.2 Carbon metric and carbon intensity .10
5.3 Calculation of GHG emissions .10
5.3.1 GHG emissions associated with energy use of a building .10
5.3.2 Measurement of energy carrier .10
5.3.3 Exported energy .11
5.3.4 Energy usage .11
5.3.5 GHG emission coefficients .12
6 Reporting and communication of the carbon metric .14
6.1 General .14
6.2 Reporting of the carbon metric.14
6.2.1 Mandatory requirements .14
6.2.2 Additional information .18
6.3 Communication of the carbon metric.19
6.3.1 Type of communication .19
6.3.2 Provision of information .20
6.3.3 Availability of information .21
6.3.4 Carbon metric disclosure report .21
6.3.5 Explanatory material.22
Annex A (informative) Aim of carbon metric .23
Annex B (informative) Building energy use defined by usage by ISO 12655 .24
Annex C (informative) Types of factors or coefficients by ISO 16346 .27
Annex D (informative) Allocation of emissions related to target energy in combined heat
and power generation by VDI 4660 Part 2 .28
Annex E (informative) Status of ISO 16745 and other documents and concepts related to
the description and assessment of greenhouse gas emissions caused by buildings .35
Bibliography .38
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ISO 16745-1:2017(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 59, Buildings and civil engineering works,
Subcommittee SC 17, Sustainability in buildings and civil engineering works.
This first edition of ISO 16745-1, together with ISO 16745-2, cancels and replaces ISO 16745:2015, of
which it constitutes a minor revision.
ISO 16745:2015, Clause 7 has been transferred to ISO 16745-2 to keep the requirements for the
verification of the carbon metric declaration independent of the requirements for the carbon metric
calculation, reporting and communication, as well as other minor editorial modifications.
A list of all parts in the ISO 16745 series can be found on the ISO website.
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ISO 16745-1:2017(E)

Introduction
Buildings contribute approximately one-third of global greenhouse gas (GHG) emissions. With its
high share of emissions, the building and construction sector has the responsibility to take the global
lead in implementing strategies to reduce GHG emissions. The building and construction sector has
more potential and opportunity to deliver quick, deep, and cost-effective GHG mitigation than any
other sectors. Carbon dioxide (CO ) emissions contribute to global warming, which is one of the most
2
recognized environmental impacts attributable to buildings.
In this context, measurement and reporting of GHG emissions from existing buildings are critical
for enabling significant and cost-effective GHG mitigation. Currently, there has not been a globally
agreed method established to measure, report, and verify potential reductions of GHG emissions from
existing buildings in a consistent and comparable way. If such a method existed, it could be used as a
universal tool for measurement and reporting of GHG emissions, providing the foundation for accurate
performance baselines of buildings to be drawn, national targets to be set, and carbon trading to occur
on a level playing field.
In principle, accurate and precise reporting can only be achieved if GHG emissions (and removals) from
all life cycle stages of buildings are measured and/or quantified. However, not all countries in the world
have sufficient capacity or resources to use and apply life cycle assessment (LCA) methodologies.
Respecting the need for collaboration on a global scale, the need exists for a metric that is usable not
only in countries with sufficient number of experts and a precise database, but also in those countries
where experts’ services are limited and databases have considerable gaps. For instance, with the
potential for global scale carbon trading within building-related sectors, a method that is consistently
usable in both the well-developed and developing world is needed.
Operational energy use in buildings typically accounts for 70 % to 80 % of energy use over the building
life cycle. Therefore, the operating stage of the building’s life cycle is the focus of measurement and
reporting of direct and indirect GHG emissions.
This document aims to set out a globally applicable common method of measuring and reporting of
associated GHG emissions (and removals) attributable to existing buildings, by providing requirements
for the determining and reporting of a carbon metric(s) of a building.
The carbon metric is a measure (a partial carbon footprint) that is based on energy use data and
related building information for an existing building in operation. It provides information related to
the calculation of GHG emissions and can be used as an environmental indicator. Using this approach,
the metric and its protocol can be applied by all stakeholders in both developing and well-developed
countries, where building energy consumption and other relevant data can be retrieved or collected,
making it useful and globally transferable.
This document aims to be practical for many stakeholders (i.e. not only for the building profession), who
are expected to use the carbon metric of a building as reference for decision making in their business
activities, governmental policies, and as a baseline for benchmarking.
The simplicity of approach provides applicability at all scales, ranging from cities and building portfolios
to individual buildings.
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INTERNATIONAL STANDARD ISO 16745-1:2017(E)
Sustainability in buildings and civil engineering works —
Carbon metric of an existing building during use stage —
Part 1:
Calculation, reporting and communication
1 Scope
This document provides requirements for determining and reporting a carbon metric of an existing
building, associated with the operation of the building. It sets out methods for the calculation, reporting
and communication of a set of carbon metrics for GHG emissions arising from the measured energy use
during the operation of an existing building, the measured user-related energy use, and other relevant
GHG emissions and removals. These carbon metrics are separated into three measures designated CM1,
CM2, and CM3 (see 5.1.1).
This document follows the principles set out in ISO 15392 and those described in Clause 4. Where
deviations from the principles in ISO 15392 occur, or where more specific principles are stated, this
document takes precedence.
The carbon metrics CM1 and CM2 are not quantified based on life cycle assessment (LCA) methodology.
Carbon metric CM3 may include partial quantification based on the results of LCA.
This document does not include any method of modelling of the operational energy use of the building
but follows the conventions provided by other International Standards, as given in relevant clauses.
This document is not an assessment method for evaluating the overall environmental performance
of a building or a building-rating tool and does not include value-based interpretation of the carbon
metric(s) through weightings or benchmarking.
This document deals with the application of the carbon metric(s) for an existing building, either
residential or commercial, or a building complex. It does not include provisions for regional and/or
national building stock.
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 6707-1:2004, Buildings and civil engineering works — Vocabulary — Part 1: General terms
ISO 12655, Energy performance of buildings — Presentation of measured energy use of buildings
ISO 14050, Environmental management — Vocabulary
ISO 15392, Sustainability in building construction — General principles
ISO/TR 16344:2012, Energy performance of buildings — Common terms, definitions and symbols for the
overall energy performance rating and certification
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ISO 16745-1:2017(E)

3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6707-1, ISO 12655, ISO 14050,
ISO 15392, ISO/TR 16344 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
building service
service provided by technical building systems (3.19) and by appliances to provide acceptable indoor
environment conditions, domestic hot water, illumination levels, and other services related to the use of
the building
Note 1 to entry: For the purposes of this document, the following terms are used as per their definitions in the
following reference documents: appliances (ISO 6707-1:2004, 5.4.7) and building (ISO 6707-1:2004, 3.1.3).
[SOURCE: ISO 52000-1:2017, 3.3.3, modified – Note 1 to entry has been added.]
3.2
carbon intensity
carbon metric (3.3) expressed in relation to a specific reference unit related to the function of the
building
Note 1 to entry: For the purposes of this document, the following terms are used as per their definitions in the
following reference documents: function (ISO 15686-10:2010, 3.10) and building (ISO 6707-1:2004, 3.1.3).
Note 2 to entry: Examples of reference units may include per unit area, per person, per kilobyte, per unit output,
and per GDP.
3.3
carbon metric
sum of annual greenhouse gas emissions and removals, expressed as CO equivalents, associated with
2
the use stage of a building
Note 1 to entry: For the purposes of this document, the following terms are used as per their definitions in the
following reference documents: greenhouse gas emissions (ISO 14064-1:2006, 2.5), removals (ISO 14064-1:2006,
2.6), CO equivalents (ISO 14064-1:2006, 2.19) and building (ISO 6707-1:2004, 3.1.3).
2
3.4
cooling
removal of latent and/or sensible heat
[SOURCE: ISO 16818:2008, 3.47]
3.5
delivered energy
energy (3.6), expressed per energy carrier (3.7), supplied to the technical building systems (3.19) through
the system boundary (3.18), to satisfy the uses taken into account [heating, cooling (3.4), ventilation
(3.20), domestic hot water, lighting, appliances, etc.], or to produce electricity
Note 1 to entry: For the purposes of this document, the term appliances is used as per its definition in
ISO 6707-1:2004, 5.4.7.
Note 2 to entry: Delivered energy can be calculated for defined energy uses or it can be measured.
[SOURCE: ISO/TR 16344:2012, 2.1.33, modified – Note 1 related to active solar and wind energy systems
has been deleted.]
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ISO 16745-1:2017(E)

3.6
energy
capacity for doing work; having several forms that may be transformed from one to another, such as
thermal (heat), mechanical (work), electrical, or chemical
[SOURCE: ISO 16818:2008, 3.74]
3.7
energy carrier
substance or phenomenon that can be used to produce mechanical work or heat or to operate chemical
or physical processes
Note 1 to entry: For the purposes of this document, the term heat is used as per its definition in
ISO 16818:2008, 3.117.
Note 2 to entry: The energy content of fuels (3.10) is given by their gross calorific value (ISO/TR 16344:2012,
2.1.78).
[SOURCE: ISO/TR 16344:2012, 2.1.46]
3.8
energy source
source from which useful energy (3.6) can be extracted or recovered either directly or by means of a
conversion or transformation process
EXAMPLE Oil or gas fields, coal mines, sun, wind, the ground (geothermal energy), the ocean (wave energy,
ocean thermal energy), forests, etc.
[SOURCE: ISO 52000-1:2017, 3.4.15]
3.9
exported energy
energy (3.6), expressed per energy carrier (3.7), delivered by the technical building systems (3.19)
through the system boundary (3.18) and used outside the system boundary
Note 1 to entry: It can be specified by generation types [e.g. combined heat and power (CHP), photovoltaic (PV)]
in order to apply different weighting factors.
[SOURCE: ISO/TR 16344:2012, 2.1.72, modified – Note 2 has been deleted.]
3.10
fuel
material that can be used to produce heat or generate power by combustion
Note 1 to entry: For the purposes of this document, the term heat is used as per its definition in
ISO 16818:2008, 3.117.
[SOURCE: ISO/TR 16344:2012, 2.1.74]
3.11
functional equivalent
quantified functional requirements and/or technical requirements for a building or part thereof for use
as a reference basis for comparison
Note 1 to entry: For the purposes of this document, the term building is used as per its definition in
ISO 6707-1:2004, 3.1.3.
[SOURCE: ISO 21931-1:2010, 3.7, modified – a reference to part of a building has been added.]
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ISO 16745-1:2017(E)

3.12
greenhouse gas emission coefficient
coefficient that describes the amount of a specific greenhouse gas that is released from doing a certain
activity, such as burning one tonne of fuel (3.10) in a furnace
Note 1 to entry: For the purposes of this document, the term greenhouse gas is used as per its definition in
ISO 14064-1:2006, 2.1.
Note 2 to entry: In general, GHG emission coefficients from specific energy consumption (ISO 50001:2011, 3.7) are
quantified based on GHG emission factors (ISO 14064-1:2006, 2.7) for use of the energy (3.6).
Note 3 to entry: Greenhouse gas emission coefficients can differ by year.
3.13
greenhouse gas reservoir
physical unit or component of the biosphere, geosphere, or hydrosphere with the capability to store
or accumulate a GHG removed from the atmosphere by a greenhouse gas sink (3.14) or a GHG captured
from a greenhouse gas source (3.15)
Note 1 to entry: For the purposes of this document, the term GHG is used as per its definition in
ISO 14064-1:2006, 2.1.
Note 2 to entry: The total mass of carbon contained in a GHG reservoir at a specified point in time could be
referred to as the carbon stock of the reservoir.
Note 3 to entry: A GHG reservoir can transfer greenhouse gases to another GHG reservoir.
Note 4 to entry: The collection of a GHG from a GHG source before it enters the atmosphere and storage of the
collected GHG in a GHG reservoir could be referred to as GHG capture and storage.
[SOURCE: ISO 14064-1:2006, 2.4]
3.14
greenhouse gas sink
physical unit or process that removes a GHG from the atmosphere
Note 1 to entry: For the purposes of this document, the term GHG is used as per its definition in
ISO 14064-1:2006, 2.1.
[SOURCE: ISO 14064-1:2006, 2.3]
3.15
greenhouse gas source
physical unit or process that releases a GHG into the atmosphere
Note 1 to entry: For the purposes of this document, the term GHG is used as per its definition in
ISO 14064-1:2006, 2.1.
[SOURCE: ISO 14064-1:2006, 2.2]
3.16
gross floor area
sum of the floor areas of the conditioned spaces within the building, including basements, mezzanine
and intermediate floor tiers, and penthouses, of headroom height 2,2 m or as specified in national or
regional codes and standards
Note 1 to entry: For the purposes of this document, the following terms are used as per their definitions in the
following documents: conditioned spaces (ISO 16818:2008, 3.38) and building (ISO 6707-1:2004, 3.1.3).
Note 2 to entry: It is measured from the exterior faces of exterior walls or from the centreline of walls separating
buildings, but excluding covered walkways, open roofed-over areas, porches and similar spaces, pipe trenches,
exterior terraces or steps, chimneys, roof overhangs, and similar features.
[SOURCE: ISO/TR 16344:2012, 2.1.79]
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ISO 16745-1:2017(E)

3.17
renewable energy
energy (3.6) from an energy source (3.8) that is not depleted by extraction
[SOURCE: ISO/TR 16344:2012, 2.1.123, modified – specific reference to energy source has been added
and the examples and explanatory note have been removed.]
3.18
system boundary
boundary that includes within it all areas associated with a building (both inside and outside the
building) where energy (3.6) is consumed or produced
Note 1 to entry: For the purposes of this document, the term building is used as per its definition in
ISO 6707-1:2004, 3.1.3.
Note 2 to entry: Inside the system boundary, the system losses are taken into account explicitly, while outside the
system boundary, they are taken into account in the conversion factor.
[SOURCE: ISO/TR 16344:2012, 2.1.142]
3.19
technical building system
technical equipment for heating, cooling (3.4), ventilation (3.20), humidification, dehumidification,
domestic hot water, lighting, building automation and control and electricity production
Note 1 to entry: A technical building system can refer to one or to several building services (3.1) [e.g. heating,
heating and domestic hot water, and indoor transportation (e.g. escalator, elevator)].
Note 2 to entry: A technical building system is composed of different sub-systems.
Note 3 to entry: Electricity production can include cogeneration (ISO 52000-1:2017, 3.3.5), wind power and
photovoltaic (PV) systems.
[SOURCE: ISO 52000-1:2017, 3.3.13, modified – indoor transportation has been added to Note 1 to entry.]
3.20
ventilation
process of supplying or removing air by natural means or mechanical means to or from a space for the
purpose of controlling air contaminant levels, humidity, odours, or temperature within the space
[SOURCE: ISO 16818:2008, 3.242]
4 Principles
4.1 General
The application of the following principles is fundamental to ensuring that GHG-related information
presented through the carbon metric represents a true and fair measure. These principles provide
the basis for the application of the requirements in this document by the organization or individual
determining the carbon metric.
4.2 Completeness
Include all relevant GHG emissions and removals (see 5.1) that provide a significant contribution to the
carbon metric.
4.3 Consistency
Apply assumptions, methods, and data in the same way throughout the carbon metric determination to
arrive at conclusions in accordance with the needs of the intended user and intended use (see 5.1).
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4.4 Relevance
Select the GHG sources, GHG sinks, GHG reservoirs, data, and methodologies appropriate to the needs of
the intended user and the intended use (see 5.3.4).
4.5 Coherence
Select methodologies, standards, and guidance documents already recognized and adopted for energy
measurement and consumption to enhance comparability between common carbon metrics (see 5.3.2)
4.6 Accuracy
Ensure that the carbon metric quantification and communication are accurate, verifiable, relevant, and
not misleading and that bias is avoided and uncertainties are minimised (see 5.3.4).
4.7 Transparency
Address and document all relevant issues in an open, comprehensive, and understandable presentation
of information.
Disclose any relevant assumptions and make appropriate references to the methodologies and
data sources used. Clearly explain any estimates and avoid bias so that the carbon metric faithfully
represents what it purports to represent.
Ensure that the carbon metric communication is available to the intended audience and its intended
meaning is presented in a way that is clear, meaningful, and understandable. Include information on the
functional equivalent, data assumptions, calculation methods, and other characteristics to make the
limitat
...