Buildings materials startup Cocoon Carbon announced that it has raised $15 million in a Series A funding round, with proceeds aimed at accelerating the commercial deployment of its low-cost and low-carbon solution to replace cement in concrete production.

Building materials are a key source of global greenhouse gas emissions. Cement production, an ingredient in concrete, accounts for approximately 8% of global carbon dioxide emissions, with more than 900 kg of CO2 emissions generated for every 1,000 kg of material produced.

Launched in 2023, London-based Cocoon provides products to help decarbonize heavy industry and create low-carbon building materials. The company is developing a supplementary cementitious material (SCM) by converting steel slag from electric arc furnaces (EAFs) – a process that produces lower-carbon steel – into a low-cost cement alternative to traditional cements processes. The product matches the performance of traditional SCMs while reducing the embodied CO2 of concrete by up to 40%, according to the company.

The solution captures molten EAF slag straight out of production and cools it 100x faster than existing technologies to produce a reliable SCM supply, while co-location at steel mills helps reduce energy use, capital needs, and transportation costs. The product is designed to be cost-competitive, avoiding a “green premium” that historically has limited new cement solutions in the market, the company said.

Cocoon said that the new capital will support the deployment of its first commercial demonstration facility in the U.S., aimed at validating performance at industrial scale and advancing plans for a broader rollout across more than 50 steel plants in the U.S. and Europe.

Eliot Brooks, CEO and Co-Founder of Cocoon Carbon, said:

“The SCM market is facing a structural deficit at exactly the moment infrastructure demand is rising. We’re focused on delivering a plug-and-play solution that gives concrete producers access to affordable, local materials while improving the economics of electric steelmaking. Expanding supply is the fastest way to stabilize costs and lower carbon in concrete.”

The funding round was led by 2150 and Brick & Mortar Ventures, with additional participation from The Venture Collective as well as existing investors Wireframe Ventures, Celsius Industries, Gigascale Capital, and SOSV.

Jacob Bro, Partner and Co-Founder of 2150, said:

“Concrete is one of the biggest value streams on the planet, providing the foundation of our civilization, from buildings to infrastructure to data centers. It consumes orders of magnitude more energy than AI and emits more CO2 than any other sector. Cocoon stands out in the innovation landscape with a product that is better and cheaper than cement and delivers a true drop-in replacement product for the industry.”