Building better with less: how we can decarbonize . . .

When we see cranes in the sky and new buildings coming up, we think about growth and prosperity, new homes for people to live in, schools and hospitals for citizens’ basic needs, and places for leisure and community bonding. But constructing these buildings is responsible for 30 percent of the built environment’s overall emissions. With the world building the equivalent of one New York city every month to accommodate the growing population, we need all hands on deck to decarbonize one of the hardest-to-abate sectors.

The good news is that green building is possible today. Traditional concrete doesn’t have the best reputation environmentally — and rightly so — but green concrete is a game changer. Concrete is the world’s most-popular building material and innovating to make it low-carbon is already helping build greener cities. Some types of green concrete get there through the extensive use of alternative materials and fuels. Some get there by incorporating construction and demolition waste. Today, we encourage customers all over the world to opt for our concrete and cement with up to 90 percent fewer CO2 emissions and no compromise on performance. Building better with less is now a reality, not just a pipedream.

Using smart design can also help build better with less. For example, 3D concrete printing can reduce material use by up to 80 percent, thus reducing its carbon footprint with no compromise on performance. We’ve deployed 3D concrete printing solutions in Africa to build affordable, quality housing and schools. At home in Switzerland, we’re partnering with the Block Research Group and the Swiss Federal Institute of Technology to create innovative solutions such as a new lightweight floor system that reduces material use by 50 percent and embodied CO2 by up to 80 percent.

With concrete being infinitely recyclable, we can have truly circular cities by using construction and demolition to build new from old without taking any more precious virgin resources from our planet. In Zurich, for example, it’s not an option, it’s a must. The Swiss city requires recycled concrete to be used in the construction of public buildings (the concrete needs to contain at least 25 percent recycled demolition waste in order to be classified as recycled). Earlier this year we achieved a circularity breakthrough at our cement plant in Altkirch, France: we produced the world’s first clinker, the main component of cement that undergoes the carbon-intensive calcination process, made entirely of recycled minerals — and we’re already scaling it to our other plants in Europe. But we’re not stopping there because next, in the very near future, we will produce 100 percent recycled cement and then 100 percent recycled concrete with the final objective of constructing the world’s first building with 100 percent recycled materials. Imagine if every new building was made from 50 percent of an old one. That means 50 percent fewer materials drawn from nature and less CO2 emissions. We already have the solutions to make this a reality.

Finally, as energy security and energy poverty become a more pressing issue than ever before, concrete is one of the most versatile materials used in buildings for temperature regulation because it absorbs, stores and releases energy efficiently — something called thermal concrete activation. We’re already seeing ‘cool schools’ popping up in Austria leveraging this simple yet highly-effective technology: the Lieselotte Hansen-Schmidt educational campus in Seestadt is carbon-free thanks to a combination of concrete core activation, heat pumps, geothermal probes and solar energy. If we start using green concrete for these ‘batteries’, we’ll have a real win-win and no one will ever have to choose between eat or heat.

Many regions already require buildings to deliver sustainable outcomes through regulation and incentives. And although zero-carbon buildings must undoubtedly become the standard in the future, we should not wait for ‘zero’ because all practical steps available today should be used to drastically reduce the whole-life carbon footprint of buildings. Smart design methods, low-carbon materials, and energy-efficient systems are practical methods available to the market today and align with pathways such as the World Green Building Council’s Net Zero Carbon Buildings framework, which requires halving emissions by 2030.

To get there, it’s essential to ensure that we have an effective, fair and reliable carbon-pricing mechanism that establishes a level playing field on carbon costs between domestic manufacturers and imports. This forms the central pillar of the low-carbon business case and is fundamental to our ability to invest on a large scale in the deployment of low-carbon technologies and products.

To create and accelerate demand for such products and technologies will require a regulatory environment and building standards/codes that incentivize greater and faster market uptake of low-carbon products by integrating sustainability performance into building codes, public procurement and product standards, alongside traditional criteria such as safety, performance, durability and affordability.

Additionally, no single solution will be perfectly scalable everywhere due to geographic, technological and legislative conditions. This means we need a flexible yet unequivocal regulatory framework that recognizes all carbon-capture technologies in carbon accounting and verification mechanisms as carbon mitigation avenues for hard-to-abate sectors.

The paradigm shift to sustainable construction has not yet fully happened, although we are seeing tremendous activity in individual cases among designers as well as certain contractors and owners. A massive shift to sustainable construction could be accelerated by adapting standards, green procurement and building codes, and we are optimistic about that. Given the complexity of this shift, no single organization can get there alone. We all have a role to play. Public authorities can evolve building norms and regulations to make material recycling mandatory. Building owners and infrastructure developers can put their procurement to work to specify more recycled materials. Companies can innovate to develop new technologies, from recycling to digital material management. It’s up to all of us to empower circular, decarbonized cities.