Cost and carbon calculator to inform design decisions

An embodied carbon calculator that integrates carbon into cost planning to enable better design decisions, supporting early-stage optimisation, delivering significant carbon and cost savings across projects.
Climate Change Mitigation Advancing Net Zero Solutions Embodied carbon

Problem Addressed

As operational energy use in buildings continues to decrease, embodied carbon is becoming a dominant contributor to whole life carbon emissions.

However, project teams often lack:

  • Early-stage visibility of embodied carbon impacts
  • Tools to link carbon performance with cost decisions
  • Consistent, data-driven methods to influence design at RIBA Stages 2–3

This results in:

  • Missed opportunities to reduce carbon when design flexibility is highest
  • Carbon treated as a secondary consideration rather than a core project driver
  • Difficulty balancing sustainability ambitions with commercial viability

 

Solution Overview

Turner & Townsend’s Embodied Carbon Calculator enables project teams to manage carbon alongside cost as a ‘dual currency’, embedding carbon decision-making into standard cost management processes. The tool focuses on upfront embodied carbon (A1–A5), where the greatest opportunity to influence outcomes exists at early design stages. It can complement whole life carbon assessments undertaken at later stages.

 

Key features

  • Identifies top carbon drivers within a design
  • Quantifies embodied carbon at elemental level
  • Provides design alternatives and optimisation opportunities
  • Integrates carbon assessment into cost planning workflows
  • Benchmarks performance against industry targets (e.g. LETI, UKGBC)
  • Includes carbon contingency to reflect design uncertainty

Approach

  • Apply carbon assessments at RIBA Stage 2 and 3
  • Use outputs to challenge design assumptions and specifications
  • Facilitate collaborative workshops with design teams
  • Optimise solutions for both carbon reduction and cost efficiency

This approach ensures carbon is treated as a core design parameter alongside time, cost and quality.

Company name

Turner & Townsend

UK availability

Yes

Solution launch date

2022

Links

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Case study

Faculty of Health, University of Sheffield

Embodied carbon assessments were undertaken at RIBA Stages 2 and 3 to inform design development and align with the client’s sustainability targets. The initial Stage 2 assessment identified an embodied carbon intensity of 844 kgCO₂e/m², alongside key carbon hotspots within the design.

In particular, the lowest floor construction accounted for approximately 25% of upfront embodied carbon despite representing only a small proportion of project cost, while concrete upper floors contributed over 10% of total embodied carbon. These insights enabled the project team to challenge design assumptions and prioritise areas with the greatest opportunity for improvement.

Through collaborative workshops, alternative design solutions were developed and implemented at Stage 3. This included rationalising the groundworks strategy and identifying more efficient fill solutions, as well as optimising the structural design of upper floors.

As a result, significant carbon and cost savings were achieved. The lowest floor construction was reduced from 535,000 kgCO₂e to 153,000 kgCO₂e, delivering a saving of 382,000 kgCO₂e and approximately £125,000. Concrete upper floors were reduced from 229,000 kgCO₂e to 113,000 kgCO₂e, saving a further 116,000 kgCO₂e and around £50,000.

Overall, the approach enabled a reduction of 121 kgCO₂e/m² between Stage 2 and Stage 3, demonstrating how early-stage embodied carbon analysis can drive meaningful reductions while improving project value.

Facts and Figures

200+

projects informing benchmark data

£5bn

value of projects utilising the calculator

Related

A Better Built Environment with the UK Green Building Council

UKGBC brings together hundreds of organisations across the built environment to accelerate practical, ambitious policy and industry action for a decarbonised, nature-positive, climate-resilience UK. We work with industry, local authorities and government to shape evidence-based policy that delivers warmer homes, lower bills, good jobs, healthier places and stronger communities.
Policy Document