What did the client need?

The client required a detailed embodied carbon assessment for a large expansion project of an energy storage facility. This would be the first assessment undertaken at the site. The aim was to support their 2025 GRI-aligned sustainability reporting, inform a voluntary carbon credit purchase, and input into possible future Science-Based Targets. They wanted to focus on upfront embodied emissions (RICS lifecycle stages A1–A5), covering:

• raw material processing;
• manufacturing of construction products;
• transportation to site; and
• energy use and waste during construction.

Beyond the assessment, the client sought insights into carbon hotspots and recommendations for future emissions reductions.

How did we support the client?

A combination of activity-based and spend-based carbon factors were used to calculate the embodied carbon associated with the energy storage facility growth project, in line with RICS 2nd Edition guidance. The embodied carbon assessment covered construction material use, fuel and energy used on site, water usage, transport distances of materials to site, and commuting data from construction workers.

A variety of data sources (from Bill of Quantities for materials and supplier specific EPDs, to waste reports and commuting data estimations) were analysed and used in calculations. OneClickLCA was used to source emissions data for products or materials, applying a data quality hierarchy in line with RICS guidance. In the absence of material quantities, a spend-based approach was used with US EEIO factors.

Where estimations and uncertainty in data quality had arisen, a standard RICS approach to contingency was applied – 15% total for Design Stage Contingency, Carbon Data Uncertainty Factor and Quantity Uncertainty Factor.

Verco recommended specific emissions reductions opportunities for the client. These were:

• lower-carbon concrete specification (already implemented in some areas with high GGBS content);
• design for material efficiency;
• onsite execution and construction logistics;
• procurement strategy and supplier engagement; and
• project carbon management.

What was the result?

Verco calculated the total upfront embodied carbon emissions for each contractor, highlighting materials with the greatest emissions contribution. Concrete and steel were identified as major emissions drivers, and some specific material types such as EnviroBuild Aluminium from China were pinpointed as emissions hotspots.

Verco provided actionable insights to improve data accuracy, carbon performance, and the design efficiency of future projects. By addressing the key sensitivities identified in this study and incorporating low-carbon design principles earlier in the process, future developments will better align with whole life carbon targets and the client’s ambitions for reduction.

Verco also introduced contracting conditions, including the provision of material quantities data by key suppliers and third-party contractors. This, as well as the prioritisation of early supplier engagement, allows for better accuracy in data provision – obtaining product-specific EPDs, for example.