Embodied carbon methodology heralds vital step for industry

A standard method for measuring the embodied carbon of building materials could prove a vital first step towards a comprehensive carbon assessment system for buildings.

The information paper Methodology to Measure Embodied Carbon of Materials has been produced by the Royal Institution of Chartered Surveyors (RICS) in direct response to the government’s Low Carbon Construction Action Plan, published in June 2011. It called for embodied carbon – that is, the impact of building materials like cement, bricks, glass etc. on the atmosphere in terms of CO2 emissions generated during manufacture, transport and construction – to be considered at every stage of the construction process as well as during operation.

The methodology is intended for use by quantity surveyors, building surveyors, building control surveyors and project managers and aims to address a current lack of consensus on how embodied carbon should be defined and calculated by setting out a practical approach to measuring carbon emissions during a building’s construction.

The paper includes calculation methodologies, tools, and data sources for measuring carbon, plus a step-by-step guide on how to conduct an assessment during the design, materials and product manufacture phases of a building project.

Martin Russell-Croucher, director of sustainability at RICS, who managed the development of this paper, said: “This paper is an important first step in producing a carbon assessment system, which will support and enable our members to deliver whole-life (embodied + operational) carbon appraisals in line with government ambitions for these to be factored into feasibility studies. By using this methodology our members can therefore contribute to the wider UK carbon reduction agenda.”

Matt Fulford, head of buildings at carbon reduction firm Sustain, who sat on the paper’s working group, added: “This will be of great support to industry practitioners… Embodied carbon should not be underestimated and is a major development area for surveyors. As the operational carbon elements of buildings reduce to near zero, embodied carbon elements become significantly higher.”

Efforts to arrive at a standard definition of embodied carbon and how it should be measured have proved a huge challenge for the industry. Although quantity surveyors already offer basic embodied carbon assessments as an extension to cost and lifecycle assessments, a more complex assessment methodology requires a greater understanding of material and resource inputs into construction.

Composite products, such as mechanical and electrical systems like boilers or air conditioning units, are particularly problematic due to a lack of product-specific embodied carbon data. And there has been confusion over how far an embodied carbon assessment should extend – material-related emissions are obviously important, but should it also cover waste generated during construction, energy used to demolish the building, or energy used to maintain or replace products?