The building blocks capture carbon dioxide at programmable levels throughout their lifespan, and are even manufactured sustainably.

A start-up firm has unveiled a range of eco-friendly bricks that absorb and permanently lock away carbon dioxide: a novel function that could transform buildings into carbon sinks and cut emissions from construction.

The firm, Earth4Earth, founded by researchers at Sheffield Technology Parks, has engineered the bricks with a process that releases virtually no greenhouse gases during manufacturer. The finished bricks are designed to draw carbon dioxide directly from ambient air throughout their lifespan as construction  building blocks.

According to the full BBC report, the technology employs a “direct air capture” approach, meaning the bricks continue to absorb atmospheric carbon dioxide after installation. Even the absorption level can be varied through customization of proprietary binders used during manufacture, to cater to different industry sustainability objectives. The bricks are certified to UK standards for durability, thermal mass, and fire resistance, and are fully recyclable: they can be crushed and reformed into new bricks or used as a soil fertilizer at the end of their lifecycle, ensuring the carbon remains trapped.

The bricks themselves are made from soil excavated from construction sites: a waste product that would otherwise be sent to landfill. The binder used to harden the soil composite is the secret ingredient. Unlike traditional brick binders, which are created by heating limestone to 1,000 degrees C (releasing carbon dioxide as a by-product and relying heavily on fossil fuels), the innovative binder is formulated at room temperature. This new process stores carbon in solid form rather than releasing it as gas, dramatically lowering the bricks’ carbon footprint.

Experts, including John Grant of Sheffield Hallam University, stress the importance of such innovations in decarbonizing the world’s construction industry. However, he has noted that widespread adoption and proof of long-term strength and reliability will be crucial for such technologies to have maximum impact.