During the Time Space Existence exhibition, organized by the European Cultural Centre in Venice, the building-solutions company Holcim and Pritzker Prize-winning architect Alejandro Aravena, with his firm ELEMENTAL, unveiled a full-scale prototype that introduces a new approach in incremental housing solutions.
The housing prototype—The Basic Services Unit—was built with Hoclim's recently launched biochar technology, which transforms buildings into carbon sinks by permanently trapping carbon in a bio-based material called biochar. This material is used as a component of low-carbon concrete, cement, and mortars.
During the Biennale of Architecture 2025 in Venice, several architects, from Aravena himself to Tatiana Bilbao and others, commented on this new technology from Holcim, sharing their opinions and hopes.
Interview with Alejandro Aravena
In order to achieve net-zero, one part is this new material, the biochar. Another part is the reuse of material—the debris coming from other sources.
Interview with Kunlé Ademyemi
The biochar, we would hope, can make concrete an even more sustainable material for development on and around water.
Interview with Jing Liu
These materials can be used in a prototype project. It has the potential to proliferate on a larger scale very quickly.
Interview with Tatiana Bilbao
The idea that this new material engages with local waste to create a different type of concrete with net-zero carbon emissions is an incredible way to start—by engaging with local economies and local possibilities, with the specific problems and contexts of the world.
Learn more about biochar and how it can help transform buildings into carbon sinks.
