Holcim has partnered with Pritzker Prize-winning architect Alejandro Aravena and his firm ELEMENTAL to unveil a housing prototype featuring new biochar concrete technology that transforms buildings into carbon sinks. The project was revealed during the 2025 Architecture Biennale in Venice and marks the first full-scale application of the technology in a Basic Services Unit housing model.
The prototype follows the principle of incremental design, offering rapid construction of essential components while allowing residents to complete their homes independently. Holcim’s concrete mix, developed for the project, includes biochar and is composed entirely of recycled aggregates, aligning with circular construction principles.
“This collaboration demonstrates how Holcim’s carbon sink technology can shape the future of construction,” said Holcim CEO Miljan Gutovic. “We continue to lead in sustainable building by working across the value chain to deliver innovative solutions.”
Aravena added: “In Venice, we are bringing incremental housing to its core: a structural sanitation unit using precast panels takes care of the basic needs of inhabitation. Holcim’s new decarbonisation technology allows us to address the scale and speed of the housing crisis’ demand without putting a strain on the environment.”
Biochar, a charcoal-like substance produced from organic matter, captures and permanently stores carbon that would otherwise be released into the atmosphere. When incorporated into low-carbon cement, mortar or concrete, it reduces their emissions footprint without compromising structural performance. One kilogram of biochar can prevent the release of up to three kilograms of CO₂.
The innovation expands Holcim’s portfolio of sustainable solutions, which also includes ECOPact, ECOPlanet, and ECOCycle®.
The collaborative project will be on display from 7 May to 23 November 2025 as part of the Time Space Existence exhibition, organised by the European Cultural Centre in Venice.
