ISO 16745-2:2017

Sustainability in buildings and civil engineering works - Carbon metric of an existing building during use stage - Part 2: Verification

ISO 16745-2:2017 specifies requirements for the verification of a carbon metric calculation for GHG emissions of an existing building during the use stage, where the carbon metric calculation is performed in accordance with ISO 16745‐1. NOTE Before verification, the carbon metric according to ISO 16745‑1 is a claim. Only after the verification according to this document can the carbon metric be communicated as a carbon metric declaration.

Développement durable dans les bâtiments et les ouvrages de génie civil — Métrique du carbone des bâtiments existants pendant la phase opérationnelle — Partie 2: Vérification

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
• Start Date: 14-Sep-2022
• Completion Date: 13-Dec-2025

Relations

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

Overview

ISO 16745-2:2017, published by the International Organization for Standardization (ISO), addresses verification of carbon metrics for existing buildings during the use stage. This standard complements ISO 16745-1 by establishing clear requirements and procedures for the independent verification of greenhouse gas (GHG) emission calculations related to a building's operational phase.

Given that buildings contribute about one-third of global GHG emissions, measuring and reporting carbon footprints accurately is essential for sustainable building management and climate change mitigation. ISO 16745-2 enables stakeholders to validate carbon metric claims, ensuring transparency, accuracy, and comparability in emissions reporting.

Key Topics

• Scope and Purpose: ISO 16745-2 focuses on verifying carbon metrics calculated according to ISO 16745-1 for existing buildings during their operational stage. Prior to verification, carbon metrics are considered claims; post-verification, they become certified declarations.

• Verification Procedure: The standard outlines a structured verification process involving:

  • Independent review of data sources, coverage, accuracy, and adherence to ISO 16745-1 principles.
  • Validation of the carbon metric declaration against original calculation data.
  • Documentation and transparent reporting of verification findings while maintaining confidentiality of sensitive information.

• Competence and Independence of Verifiers: Verifiers must be impartial third parties with no conflicts of interest and possess sector-relevant expertise including:

  • Energy use in buildings
  • Applicable carbon metric methodologies
  • Knowledge of regulatory frameworks and related standards

• Data Confidentiality: The standard enforces confidentiality rules ensuring proprietary or sensitive business data is protected during the verification process.

• Definitions and Terminology: The document clarifies core terms such as "carbon metric," defined as the sum of annual GHG emissions and removals expressed in CO₂ equivalents for the building's use stage.

Applications

ISO 16745-2 is an essential tool for:

• Facility Managers and Building Owners: To substantiate the carbon performance of their buildings ensuring validated and credible carbon metrics for operational energy use.

• Environmental Consultants and Auditors: Providing guidance for independent verification audits of existing buildings’ GHG emissions.

• Governmental and Regulatory Bodies: Facilitating verified reporting to support policy decisions, sustainability targets, and carbon trading frameworks.

• Sustainability Certification Programs: Integrating verified carbon metric declarations for benchmarking and environmental labeling.

• Real Estate and Investment Sectors: Enabling transparent communication of verified carbon metrics, supporting greener investment strategies.

Related Standards

ISO 16745-2 closely interacts with several other key international standards:

• ISO 16745-1:2017 - Calculation, reporting, and communication of the carbon metric for buildings during the use stage.

• ISO 14064-1 - Specification and guidance on quantification and reporting of GHG emissions and removals at the organizational level.

• ISO 6707-1 - Vocabulary related to buildings and civil engineering works.

• ISO 14021, 14024, 14025 - Environmental labels and declarations frameworks relevant for self-claims and environmental product declarations.

• ISO 21929-1 and ISO 21931-1 - Frameworks for sustainability indicators and assessment of the environmental performance of construction works.

• ISO 16343 and ISO 16346 - Methods for expressing and assessing energy performance of buildings.

Implementing ISO 16745-2 ensures consistent verification methodologies for carbon metrics, fostering reliable data crucial for sustainable building management and advancing global efforts to reduce the environmental impact of the built environment.

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Keywords: ISO 16745-2, carbon metric verification, greenhouse gas emissions, building sustainability, operational energy use, carbon footprint, existing buildings, environmental performance, independent verification, GHG reporting, sustainability in buildings.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 16745-2
First edition
2017-05
Sustainability in buildings and civil
engineering works — Carbon metric of
an existing building during use stage —
Part 2:
Verification
Développement durable dans les bâtiments et les ouvrages de génie
civil — Métrique du carbone des bâtiments existants pendant la phase
opérationnelle —
Partie 2: Vérification
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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Fax [phone]
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www.iso.org
ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Verification . 2
4.1 General . 2
4.2 Procedure for review and independent verification . 2
4.2.1 Independent verification of data . 2
4.2.2 Verification of the carbon metric declaration . 2
4.2.3 Independence and competence of verifiers . 2
4.2.4 Rules for data confidentiality . 3
Bibliography . 4
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 edition of ISO 16745-2 together with ISO 16745-1 cancels and replaces ISO 16745:2015, of which
they constitute 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 the parts of the ISO 16745 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

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
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 informatio
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