Fergus Wooler
December 8, 2024
How to halve the carbon footprint of new builds
Concrete production is responsible for 7% of global emissions and is the most widely used construction material in the world. A new study by the Danish concrete association, Dansk Beton, has concluded that too much concrete is used in buildings and smarter design methods combined with lower emission types of concrete can almost halve a new building’s carbon footprint and significantly reduce material consumption.
There is a widespread perception in the construction industry that too many materials are used in new builds, which has intensified the focus on reducing concrete use and reinforcing structures. To bring attention and transparency to this issue, Dansk Beton initiated a study on an existing concrete building to determine potential material savings and carbon emission reductions.
“There has previously been a lack of data regarding the reductions in material use and carbon footprint that can be achieved if design is optimised and the lowest emission concrete types are used. We have now obtained this data, and it is enormously valuable.”
Danish pension provider and property developer, AP Pension, made one of its existing properties available for the analysis comprising a five-storey residential building with a basement and an eight-storey residential tower block. The construction is traditional precast concrete with both internal prefabricated walls, sandwich façade panels and hollow core decks.
The analysis reveals that through design optimisation - using lower concrete strengths, different wall and deck dimensions as well as optimised foundations and basement walls - a material saving of 21-25% concrete and 5-35% in reinforcing structures can be achieved. Overall, this corresponds to around a 25% reduction in the carbon footprint using solutions that are within current applicable norms and standards.
The approach to design optimisation employed the tool, "Basis for Dialogue for Design Optimisation of Concrete Structures", which was developed by Dansk Beton and several suppliers as well as consulting companies. The tool was used as a starting point for the study, and the early generation of ideas together with suppliers provided useful suggestions for solving the task.
The analysis also shows that using the lowest emission concrete materials available on the market today, can further reduce the building’s carbon footprint by approximately 20-25 percent compared to 2018, when the building was constructed.
The calculations demonstrate that the vision of halving the carbon footprint from concrete construction, which the concrete industry put forward back in 2019, can already be fulfilled today. The industry has since raised the ambition to a 70% reduction in carbon emissions by 2030.
“It is very positive to see that concrete construction is becoming more sustainable. A lot of concrete is still used in wooden buildings as well. Therefore, as a developer, we have a strong focus on not just looking at alternative materials – but also keeping an eye on the fact that the producers of more traditional building materials are moving in a more sustainable direction,” says Morten Leen, Chief Sustainability Officer at AP Pension.
“The findings from this analysis are promising in that they are also relevant in other countries and in larger scale building developments where many of the same conditions and principles often apply,” concludes Tim Gudmand-Høyer who is a concrete expert at Ramboll and project manager on the study for Dansk Beton.
Click on the link to download the full analysis (in Danish).
Want to know more?
Tim Gudmand-Høyer
Senior Chief Engineer
+45 51 61 83 19