New construction technology stores CO2 in buildings
Holcim and the ELEMENTAL architecture firm of the multi-award-winning Chilean architect Alejandro Aravena have developed a biochar technology that transforms buildings into carbon sinks. It will be presented at the Architecture Biennale in Venice from 10 May.
Holcim and ELEMENTAL are presenting a new method for binding carbon in buildings at the Architecture Biennale in Venice, according to a press release. This new biochar technology will be presented there from 10 May to 23 November 2025 as part of the Time Space Existence exhibition. It is being organised by the European Cultural Centre.
On display will be full-size, minimalist prefabricated parts of a prototype for so-called incremental housing construction. The structures on display were designed by ELEMENTAL and are based on two decades of research. They consist of prefabricated concrete frames with sanitary infrastructure that can be used to build homes for low-income people in economically disadvantaged areas.
These prefabricated elements were built by Holcim. They consist of 100 per cent recycled aggregates and biochar. Biochar binds CO2 permanently, which would otherwise be released by organic materials at the end of their life cycle. As Holcim calculates, one kilogramme of biochar prevents the release of up to three kilogrammes of CO2. This biochar is added to Holcim’s low-CO2 cement, mortar and concrete mixes. This further reduces their CO2 footprint without compromising their performance, as Holcim emphasises.
“Holcim’s new decarbonisation technology allows us to cope with the scale and speed of demand fuelled by the housing crisis without harming the environment,” ELEMENTAL founder Alejandro Aravena is quoted as saying. Holcim CEO Miljan Gutovic adds: “Through our partnership with Alejandro Aravena and the ELEMENTAL team, we have shown how Holcim’s new carbon sink technology can shape the future of construction.”