How are we measuring and reporting embodied carbon emissions?
The Construction Carbon Problem
Every hour, 1 million tonnes of CO2 is produced from construction activities. To compound the problem, annual decarbonisation progress in construction almost halved from 2016 to 2019. In order to get on track for our 2050 net zero target, we need to half all building emissions by 2030.
Why measure Carbon?
Data is critical in the implementation of large scale change. However there is a lack of carbon data in the construction industry. This makes carbon budgeting, benchmarking, and legislating difficult. The more whole-building, whole-life carbon data we have, the better we can identify key trends and insights, helping us to identify the best route to decarbonisation.
Moreover, a robust dataset will be the ultimate tool in low-carbon and sustainable infrastructure planning. At the low level it would serve as a valuable referencing resource for industry use. At the high level it will be a key indicator of carbon trends in the built environment. Additional applications involve prediction modelling and API-first technology. The absence of this dataset is a blocker for clean innovation.
Finally, measuring carbon is becoming an essential priority to businesses. Globally, the percentage of retail and institutional investors that apply ESG principles to a quarter or more of their portfolios leapt from 48% in 2017 to 75% in 2019. Legislation is also being introduced across Europe and the Americas mandating carbon metrics in construction planning.
There are different ways to measure and report your construction carbon. Here we mention a few schemes that we interact with (we’re UK based).
MEASURE: Greenhouse Gas (GHG) Protocol
The GHG protocol is a series of standards to measure and manage a company’s emissions. Most commonly used is ‘The Corporate Standard’ which represents a framework of accountability for carbon reporting. Categories of emissions are divided into scopes, relating to the source of emissions. Scope 1 involved the direct emissions from the activities of the organisation, such as fuel burnt for the manufacture of a product. Scope 2 involves emissions from indirect sources of energy, such as purchased electricity.
Scope 3 emissions are a little more complex, and can often make up the majority of carbon footprint, taking into account all emissions in the value chain. This may include upstream activities such as the processing of upstream materials, outsourced activities, employee commuting. As well as downstream activities such as waste management and product use cases. The scope is outlined in the guidance note ‘Corporate Value Chain (Scope 3) Accounting and Reporting’ from the GHG protocol.
MEASURE: RICS Whole Life Carbon Assessment (WLCA) / EN 15978
Proposed in 2017 from the RICS, the WLCA is a methodology of building carbon assessment, based on life cycle assessment principles. It’s derivative of the European standard EN15978, which covers every aspect of a building’s life cycle for its environmental, social, and economic performance.
Similar to Scope 1–3 of the GHG protocol, the WLCA boundary includes all aspects of the construction value chain. The framework is made up of 4 major categories; Product stage (raw material extraction, transportation to plant, and manufacture), Construction stage (transport to site and construction), use stage (maintenance & replacement, and operational emissions) and end of life (demolition, transport to disposal facility & waste processing). There is also a 5th module to include the benefits and loads beyond the system boundary (similar to Scope 4 emissions in the GHG protocol), indicating the building’s circularity. This can be reported separately but does not alter the building’s WLCA score.
The RICS WLCA allows construction organisations to accurately and precisely monitor carbon across their schemes. It is also a tool to lower carbon at design stage. It is an appropriate method for most construction companies to use due to the accessibility of the upstream data required, however the analysis can be time consuming due to the decentralised nature of the data required. WLCA is now mandatory on major development in the Greater London Area.
REPORT: Carbon Disclosure Project (CDP)
The CDP is a global ESG (environmental, social and governance) disclosure system for businesses and stakeholders. It’s one of the largest ESG organisations, with nearly 1/5th of GHG emissions being reported through the CDP.
The CPD’s carbon reporting process is based on the GHG protocol, with a number of accepted upstream methodologies (see CDP Climate Change Scoring Methodology) for data collection. Once you have measured your company’s carbon, you can then fill in a CDP questionnaire, armed with your measured environmental impact metrics.
The questionnaire is based on the CDP’s core principles of sustainable development, however sector and geography are taken into account. You can report Scope 1, 2 and 3 emissions, as well as emissions from biologically sequestered carbon and emission intensities.
Based on how the information you provide, the CPD will score you based on its 4 levels of environmental stewardship: disclosure, awareness, management and leadership. The company will then be awarded a grade from A-D.
Written by Isabelle Gough.
There are many other carbon schemes out there. Here we mention a few, are you using a different one? Drop it in the comments.
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