CARBON CALCULATOR

An urgent challenge

The built environment is now one of the defining fronts in the global effort to tackle climate change. Buildings are responsible for 39% of global energy‑related carbon emissions, with 11% coming directly from the embodied carbon of materials and construction alone. In the UK, a quarter of all national emissions can be traced back to the built environment. And with the world constructing the equivalent of a new Paris every week, the scale and urgency of the challenge are only increasing.

of global energy-related carbon emissions come from buildings

of UK emissions are directly attributable to the built environment

of global carbon comes from the embodied carbon of materials and from construction of buildings

EXPECTATIONS

Data-led decisions

It is within this context that we have embedded our Embodied Carbon Calculator (ECC) into this year’s report. By integrating carbon assessment into the same workflows used to manage cost, we help clients make informed, value-driven decisions that support their net-zero carbon ambitions without compromising commercial outcomes.

Our calculator measures embodied carbon in line with the RICS Whole Life Carbon Assessment Professional Statement, ensuring consistency, comparability and confidence at every design stage. It enables rapid assessment of design options, clear benchmarking against industry targets such as LETI 2030 and UKGBC 2030, and early identification of opportunities to reduce carbon while maintaining programme, quality and cost certainty.

Key legislation

In the UK, all new buildings must be net-zero Carbon in operation by 2030, and all buildings must achieve net-zero Carbon, both upfront embodied and operational, by 2050.
The European Union has revised its Energy Performance of Buildings Directive (EPBD). From 2028, new buildings with a floor area greater than 1,000m² must calculate and report their whole life-cycle global warming potential (GWP).
The US has no federal target, however, California has set a 40% net reduction in embodied carbon emissions for new buildings by 2035 with an interim 20% target by 2030.

EXPECTATIONS

ECC example cost plan for London

We have applied our Embodied Carbon Calculator (ECC) directly to the London cost plan, the basis of the cost data in this guide, to demonstrate how cost and carbon can be evaluated together from the earliest design stages.

By mapping each elemental component of the cost plan to verified carbon factors in line with the RICS Whole Life Carbon Assessment v2 methodology, we are able to generate a transparent, auditable view of the project’s upfront embodied carbon alongside its commercial profile.

This integrated approach highlights which elements, such as MEP systems, structural interventions and high‑volume materials, are driving the greatest carbon intensity, enabling us to challenge assumptions, explore lower‑carbon alternatives, and quantify the cost implications of each option in parallel.

As can be seen in the summary table, the total upfront embodied carbon based on the London cost plan is 825,000kgCO2e, equating to 353kgCO2e/m2 of the fit-out area.

To help drive lower carbon outcomes, the ECC automatically identifies the top ten carbon-intensive items and materials within the cost plan. This makes it straightforward to focus on areas of the design where the greatest carbon reductions can be achieved at best value.

For the London cost plan, the highest carbon-intensive item is the raised access floor, accounting for approximately 55% of the total emissions for measured items, while representing just over 3% of the total construction cost. By selecting a lower-carbon alternative product, a saving of approximately 100,000kgCO2e can be achieved at a relatively small cost premium of around £5/m2. Similarly, introducing a circular economy approach - using a recycled and re-certified panel on new pedestals - would deliver a further saving of around 100,000kgCO2e for a comparable cost premium.

With online material trading platforms becoming increasingly sophisticated, and material suppliers in London operating buy-back and refurbishment schemes, the circular economy approach is gaining traction. When planned and implemented properly, it represents a viable and effective solution for reducing the carbon impact of fit outs.

As shown in the image below, carbon is reported in elemental format, making it simple to benchmark, compare and seek improved outcomes in exactly the same way as cost. We are increasingly seeing clients set explicit carbon targets for their fit outs; therefore starting carbon assessments at concept stage and pursuing more efficient design solutions as part of the standard value improvement process is strongly recommended to help achieve these targets at best value.