ETH Zurich research shows how reused concrete can cut carbon

Reusing existing building materials such as structural concrete and steel could dramatically reduce emissions across the construction industry, according to new research from ETH Zurich. The work, led by Professor Catherine De Wolf, explores how circular construction practices can keep valuable materials in use, cutting both embodied carbon and waste.

De Wolf, Professor of Circular Engineering for Architecture at ETH Zurich, is pioneering techniques to give concrete and steel elements a “second life.” Her team has shown how façades, slabs and beams from existing structures can be re-engineered and reinstalled — avoiding demolition and the high energy costs of producing new materials. In one high-profile example, glass components from the Centre Pompidou in Paris were salvaged and reused as office partitions rather than discarded.

“The cheapest option is often to demolish and start again,” said De Wolf, “but we need to ensure the cost and effort of circular construction are no higher than today’s linear approach.” Her research advocates automating the recovery of materials, creating digital marketplaces for reclaimed components, and developing “material passports” to document each element’s history, performance and carbon footprint.

Although based in Switzerland, De Wolf’s work has clear relevance for the UK. With the government’s Net Zero 2050 target and the built environment accounting for around 25% of UK emissions, retrofit and reuse are increasingly seen as essential. Adopting ETH’s data-led methods could strengthen the UK’s emerging Circular Construction and Retrofit Strategy, helping to reduce embodied carbon in structural concrete and steel — two of the sector’s biggest emitters.

The ETH research also supports global efforts to make the construction supply chain more sustainable. By promoting modular design, reversible connections and digital record-keeping, De Wolf’s team aims to ensure that every material — from concrete slab to steel beam — can be tracked, maintained and reused safely.

As the UK concrete and construction sectors invest in low-carbon mixes, cement substitution and recycled aggregates, experts say the next frontier lies in reuse. Research like De Wolf’s highlights how architecture, engineering and data science can work together to build more — with less.