London-based Cocoon Carbon has secured $15 million in Series A financing to accelerate deployment of its low-carbon cement alternative. The round was led by 2150 and Brick & Mortar Ventures, with participation from The Venture Collective and existing backers including SOSV.
The funding will support the development of Cocoon’s first commercial demonstration facility in the US, along with team expansion across both the US and UK.
Cocoon addresses a critical structural challenge in construction: the shrinking supply of supplementary cementitious materials (SCMs), which help reduce concrete’s carbon footprint. Traditionally sourced from coal-fired power plants and blast furnaces, SCMs are becoming scarce as high-emission industrial processes are phased out.
To solve this, Cocoon converts steel slag, a byproduct of electric arc furnace (EAF) steelmaking, into a cement substitute. Rapid cooling technology applied directly within steel production systems creates a consistent, scalable supply of SCMs without requiring new infrastructure. Co-locating with steel mills reduces transportation costs and emissions, while producing a material that can cut concrete’s embodied carbon by up to 40% without sacrificing performance.
Unlike many low-carbon alternatives, Cocoon’s solution is designed to remain cost-competitive, avoiding the “green premium” that often slows adoption in construction.
The new capital will validate the technology at commercial scale and support a broader rollout across more than 50 sites in North America and Europe by 2035, positioning Cocoon as a scalable solution to stabilize material costs and reduce emissions in one of the world’s most carbon-intensive industries.
