Comment: Decarbonising the built environment from the ground up

The built environment accounts for around 40 per cent of global carbon emissions and therefore plays a vital role in global efforts to combat climate change. Recognising this, Holcim’s team of researchers, scientists and engineers have developed a decarbonisation strategy addressing four key areas that the industry needs to tackle in order to work towards a greener building environment: greening building materials, building better with less, promoting sustainability in buildings, and driving circular construction. Together, these pillars work in conjunction to reduce the environmental impact of construction and help the whole industry transition towards a more sustainable future.

Greening building materials

The first pillar, greening building materials, involves decarbonising operations by incorporating green energy and green mobility throughout. Cement production is responsible for about eight per cent of the world’s carbon emissions. The environmental impact of steel is roughly comparable. A critical aspect of decarbonisation in cement production is reducing the use of clinker, a major source of CO2 emissions. This means replacing it in our cement with mineral components like calcined clay and novel binders. By 2030, we aim to reduce clinker content to the extent that we reduce our CO2 emissions in Europe by 50 per cent.

The push towards lower emissions doesn’t stop with materials. We need to leverage advanced technologies like carbon capture, utilisation, and storage (CCUS), which has the potential to be a game-changer in the construction industry’s fight against climate change.

Building better with less

The second pillar is building better with less. The industry needs to focus on reducing material usage without sacrificing performance. This includes the use of 3D printing and design optimisation, allowing material usage to be cut by up to 80 per cent. As well as improving efficiency, this approach has the potential to reduce waste and resource consumption, while also addressing critical infrastructure gaps. With over 1.6 billion people lacking access to adequate housing and sanitation, 3D printing can be deployed to provide schools and homes, ensuring no-one is left behind.

To this end, the industry needs to forge strategic partnerships with leading academic institutions. For instance, Holcim has extensively collaborated with the Massachusetts Institute of Technology (MIT) and the Swiss Federal Institute of Technology (ETH), to develop design solutions that significantly reduce upfront carbon emissions. By using optimised design and strategically placing the right materials within structures, substantial CO2 savings can be achieved. This, combined with greater efficiency in the construction, has the potential to significantly reduce absolute carbon emissions in construction.

Enhancing sustainability in the built environment

The third key component of carbon reduction centres on promoting and enhancing sustainability in the built environment. This includes working to enhance energy efficiency to promote green retrofitting, ensuring that buildings are more environmentally sustainable throughout their life cycles and reducing embodied carbon emissions.

Adapting the public realm to be more biodiverse and resilient to climate change is another way in which the architecture, construction and engineering sector can help address the climate crisis. This can include urban greening on building facades and roofs, but also using permeable concrete to allow the restoration of groundwater. within the public spaces to combat urban heat islands, increase biodiversity and filer air pollution, to creating a public realm that is resilient to drought as well as torrential rain. 

Circular construction

Circular construction is the fourth pillar of a decarbonised built environment. When buildings and infrastructure can no longer be retrofitted and reused, we should be looking to incorporate construction demolition waste within new materials. This is already possible with the most common building materials, such as aluminium, steel, glass and concrete. At Holcim, we have recycled 8.4 million tons of CDM (construction and demolition materials) last year, a 24 per cent increase compared to 2022. We are on track to meet our target of recycling 10 million tons of CDM by 2025, and to expand recycling operations to 150 centres across Europe by 2030.

To achieve these goals across the sector, however, we need collaboration from key stakeholders and decision makers. Materials can incorporate CDM without loss of quality, but the use of these innovative materials can be hindered by outdated regulation and lack of knowledge. If we are to make a meaningful shift from a carbon and material-intensive cradle-to-grave model to a more circular approach, we need to push for wider recognition and acceptance of these materials with regulators, and within our industry more widely.

To decarbonise, the construction industry needs to reinvent itself. By moving from volume to value, we can transforming the way materials are produced and used, shifting towards low-carbon, circular, energy-efficient, and sustainable materials. We believe that through continued innovation, collaboration, and knowledge sharing, we can build towards a greener future for the industry, and for the world.

Edelio Bermejo, head of global R&D and innovation at Holcim