Case Studies
Using innovative digital tools to help customers manage and reduce their carbon emissions.
CarboniCa is our in-house innovative carbon calculation tool that allows our project teams to work with our customers to estimate, manage and reduce whole life carbon emissions through the design, construction and entire lifecycle of an asset.
The tool has been developed to help support and empower our clients to make environmentally friendly decisions based on meaningful and robust data, in order to reduce the harmful effects of carbon emissions on local communities.
Using CarboniCa, we were able to work with HLM and Arup (the project's design lead and planner and estimator) at design stage 3 to seek opportunities for where we could reduce carbon at preconstruction stage of the project.
We took the CarboniCa design recommendations for the building and issued to the design team for review. Targets have been set based on the stage 2 cost plan and include;
Investigation of ground improvement techniques enabling a pad foundation design saving 20 tonnes embodied carbon.
Rationalisation of column and beam sizes and sourcing of lower carbon steel to realise an estimated 1% saving in embodied carbon (or 1 tonne of carbon).
For the roof and upper floors, the project team are investigating using the concrete planks for thermal mass to see if operational energy demand can be reduced by 1% or 82 tonnes over 60 years.
We worked with our supply chain partner, Sigmat Limited, to find alternative solutions to the project's structural frame. We consulted the client and let them know that changing the concrete frame to a lightweight steel frame would create huge carbon savings.
By using CarboniCa we were able to carry out a comparison of the two frame options and calculate the embodied carbon at practical completion. The lightweight steel frame saved 8% or 177 tonnes of carbon.
Working with our strategic supply chain partner Speedy, we switched from using red diesel to HVO (Hydrotreated Vegetable Oil). The project has estimated 25,000 litres of this fossil-free fuel can be procured. This will equate to a carbon saving of 70.5 tonnes. The fuel also results in improved local air quality as exhaust emissions contain less Nitrogen Oxides and harmful particulate matter.
We undertook workshops in conjunction with our supplier Roger Bullivant to change the piling technique, realising that if we changed this, we could save the client money and reduce their carbon simultaneously.
We switched the piling to a displacement technique meaning less waste soil was generated. In addition, less material (concrete/reinforcement) was required saving money and embodied carbon within the project. The carbon savings have also been calculated for the soil which would have had to be removed for disposal and transported from the project. In total this change saved 9.65 tCO₂e of carbon.
Using CarboniCa, the embodied carbon savings were also calculated from an estimated reduction of 20m3 of concrete and associated rebar.
The project is a Passivhaus scheme which demands best practice energy efficiency measures and a very low heating demand per square meter. The required standards were achieved to meet Passivhaus standards and then working with the supply chain, we ensured that the insulation and air tightness was as rigorous as possible without wasting material. By using CarboniCa, the heating requirement was reduced from 15 to 14kWh/m2/year through the design choices of wall and roof insulation.
The project team have reduced the operational energy for space heating even lower than the required standard resulting in a further saving of 80 tonnes of carbon over the school's lifetime.
By running the project through CarboniCa, the team have saved the project a total 1,977 tonnes of CO2e against the baseline design.
The carbon reductions have been achieved through:
✅ Reducing the pile diameter meaning less concrete was required
✅ Changing the concrete mix in the foundations and floor slabs to substitute the cement content for a lower carbon replacement
✅ Using lower carbon rebar; procured lower carbon steel for the frame and rebar (produced via an electric arc furnace which is a much cleaner manufacturing process)
✅ Reduced the volume of the structural framing system and switched from cement particle board to Glasroc X which has a lower carbon footprint
