Researchers at ETH Zurich have created a construction material that is alive, captures CO2, and can repair itself. If it works at scale, it would turn buildings from carbon sources into carbon sinks, merging structural function with carbon removal in a single product.

Why it matters

The built environment is responsible for roughly 37% of global CO2 emissions when you count both construction and operation. Concrete alone accounts for about 8% of worldwide emissions. A material that absorbs carbon dioxide while serving as a structural component would attack the problem from both sides: reducing the emissions footprint of construction and actively pulling CO2 from the air over the building’s lifetime. That is a fundamentally different proposition from simply making concrete “less bad.”

What we know

Details on the exact composition and mechanism are limited from the source reporting, but here is what has been shared. ETH Zurich researchers developed what they describe as a “living material” for construction. The material has two defining features:

  1. Carbon capture. It actively absorbs CO2, presumably through biological processes embedded in the material itself.
  2. Self-repair. It can mend its own damage, which implies living organisms (likely bacteria or microalgae) are integrated into the material’s structure and remain metabolically active after the material is placed. The concept of bio-integrated construction materials is not entirely new. Researchers have previously experimented with bacteria-infused concrete that can seal its own cracks. But combining that self-healing property with active carbon dioxide capture in a single material is a meaningful step forward. It suggests the biological component is doing double duty: fixing structural damage and sequestering carbon through metabolic activity like photosynthesis or biomineralization.

Implications

If a living building material can be validated and produced at reasonable cost, several things change for CDR and construction: Buildings become removal infrastructure. Right now, buildings are liabilities on the carbon ledger. A material like this flips the equation. Every square meter of wall or floor becomes a surface that pulls CO2 from the surrounding air. The sheer surface area of the global building stock is enormous, which means even modest capture rates per unit area could add up. Reduced maintenance costs could drive adoption. Self-repair is a powerful selling point independent of the carbon story. Concrete degradation is a multi-billion-dollar problem worldwide. If a material can heal its own cracks, building owners save money on maintenance. That economic incentive could pull the material into the market faster than a carbon-removal pitch alone. Permanence questions get interesting. In CDR, durability of storage matters. If carbon is captured biologically and then mineralized into the material’s structure, that could represent long-duration storage on the order of decades to centuries, matching the lifespan of the building itself. But if the carbon is stored in living biomass that could decompose, the permanence picture is murkier. A new category for carbon credits? Construction materials that actively remove CO2 don’t fit neatly into existing carbon credit methodologies. Measurement, reporting, and verification (MRV) frameworks would need to account for capture rates that change over time, the carbon embodied in manufacturing the material, and what happens at end of life when a building is demolished.

Caveats

This is early-stage research from a university lab. Several big questions remain unanswered based on available reporting: Scale and cost. Lab materials and commercial building products are separated by a vast gap. Can this material be manufactured at volumes and prices that compete with conventional concrete or other construction materials? We don’t know yet. Capture rate. How much CO2 does the material actually absorb per kilogram or per square meter per year? Without these numbers, it is impossible to assess whether the carbon removal contribution is meaningful or marginal. A material that captures a few grams of CO2 per square meter annually would be a curiosity. One that captures kilograms would be significant. Net carbon balance. What are the emissions associated with producing the material? If manufacturing it is energy-intensive or requires carbon-heavy inputs, the net removal could be small or even negative. A full lifecycle analysis will be essential. Longevity of the living component. Keeping organisms alive inside a construction material for years or decades is a serious biological engineering challenge. Temperature extremes, drying, UV exposure, and chemical stress could all kill the living component. If the organisms die, the material loses both its capture ability and its self-repair function. Structural performance. Does it meet building codes? Can it bear loads? Is it fire-resistant? These are non-negotiable requirements for any construction material, and biological components could complicate all of them.

The bottom line

ETH Zurich’s living material is a compelling concept that sits at the intersection of CDR and the built environment. It represents a category worth watching: passive carbon removal embedded in products people already need. But it is a long way from a lab demonstration to a material you can order from a supplier. The next milestones to look for are published capture rates, lifecycle carbon assessments, and any partnerships with construction companies willing to test it in real buildings.

Source: Carbon Herald