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Beyond Steel and Concrete: Catching Up with TechnoCarbon

The majority of tall buildings are built with steel and concrete, but they no longer have to — and Pierre-Carbone is part of this shift.

This award-winning innovation from European startup TechnoCarbon uses composite technology to turn stone into an alternative to less sustainable and durable construction materials. Since winning the JEC Composites Startup Booster in 2024, TechnoCarbon has hit major milestones, including a seed round that helped fund its first experimental innovation and manufacturing center.

But scaling disruptive materials isn’t just about the breakthroughs — it’s about building credibility with industrial players, and turning recognition into partnerships. We caught up with founder and CEO Stephan Savarese for a candid discussion about challenges of bringing a disruptive product to market, the wins and surprises along the way, and what’s next for this startup born to create a new path towards sustainable architecture, industry and cities.

How would you briefly describe what your technology does?

TechnoCarbon’s innovation, Pierre-Carbone, uses composite technology to turn stone into the first sustainable material to outperform steel and concrete for heavy-duty applications. This is a gamechanger for architecture and industry, because the current paradigm is that it’s impossible to build efficient and tall buildings and structures without steel and concrete. However, these materials have issues that cannot be easily fixed: carbon and freshwater footprint, corrosion, and fatigue.

Can you share a concrete example of how it can be used?

Our first products are solar power plant structures. We’ve already built 2 demonstrators: wayside solar power plants and solar PV carports, where aluminum and steel have been replaced with Pierre-Carbone, thereby saving 50 tCO2 per 100 sqm. That’s 80 Paris-New York flights!

How did winning the JEC Startup Booster change your business?

In an instant, getting recognition from the industry changed our status from just another tech startup without a clear future into an award-winning startup deserving attention from major industrial groups.

We had already received support from Airbus for one demonstrator, but that was not enough to circumvent skepticism about the versatility and market-fit of the technology. It does take some official recognition from several industrial players to alleviate unavoidable defiance towards disrupting innovation!

What are the most significant milestones you’ve hit since winning? Any surprises?

July 2024: closed our seed round, enabling investment into our experimental innovation and manufacturing center.

July 2025: the center reached 100% autonomous production meeting performance standards required for product launch.

October 2025: installed our first solar carport demonstrator, soon to be commissioned.

Any surprises? Yes, winning the JEC Startup Booster Award in 2024 (France team) and JEC Innovation Award in 2025 (Germany team) were great surprises! Being selected for VDS 2025’s TOP50 European startups was also an amazing surprise, as well as the EA ecoentreprises Innov’éa 2025 award.

Next big surprises to come: who will become our next investors and customers?

What’s your top priority for 2026?

Increase sales and reach breakeven of this first manufacturing center, which is still experimental, so suitable for innovation and demonstrators, but less than optimal for production, even in small series.

This entails securing our next purchase orders — sales cycles are long, so we know which ones these will be, but we do not know when and in which order: making it happen is a time-consuming task! We will also be switching to repetitive sales; procuring and installing new equipment to increase production efficiency; and finally, hiring more operators and production engineers to switch to morning and evening production schedules.

Hence, the experimental innovation and manufacturing center will become an innovation, training, and industrialization factory.

What’s the one thing you wish you’d known about the composites industry before starting?

Thanks to JEC World, I believe we had the general information we needed since 2019. Finding the right partners and suppliers took quite some time, though. We finally found them at JEC World 2024, thanks to a combination of multiple factors, so one could think it had to be this way and we were not ready to find them before!

Note: This article is part of a commercial collaboration between JEC and Sesamers. Our team retained full editorial control over the questions and final content.

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London-based AI laboratory Ineffable Intelligence has emerged from stealth with a $1.1 billion seed round at a $5.1 billion post-money valuation, the company confirmed on 27 April 2026. The financing is the largest seed round ever raised by a European company and one of the largest first-money-in rounds in the global history of artificial intelligence. The round was co-led by Sequoia Capital and Lightspeed Venture Partners. Participating investors included Nvidia, DST Global, Index Ventures, Google, and the UK Sovereign AI Fund, the British government’s recently established vehicle for backing strategic AI capacity on home soil. A bet on a different path to general intelligence Ineffable Intelligence was founded in 2025 by David Silver, the former Vice President of Reinforcement Learning at Google DeepMind and the principal architect of AlphaGo, AlphaZero and AlphaStar. He is joined by three further DeepMind alumni: Wojciech Czarnecki, Lasse Espeholt and Junhyuk Oh. All four have spent the past decade at the frontier of reinforcement learning research, the discipline behind some of the most consequential demonstrations of machine learning over the past ten years. The company describes its objective as building a “superlearner” — an AI system capable of acquiring knowledge directly from its own experience rather than from human-generated text or imagery. “Our mission is to make first contact with superintelligence,” Silver said in a statement accompanying the launch. “We are creating a superlearner that discovers all knowledge from its own experience, from elementary motor skills through to profound intellectual breakthroughs.” The framing is a deliberate departure from the dominant industry trajectory. Most leading AI laboratories, including OpenAI, Anthropic and Google DeepMind itself, have built large language models trained primarily on the corpus of the internet, then refined that training with human feedback. Ineffable’s wager is that the marginal returns on scaling text-based pretraining are diminishing and that the next leap in capability will come from agents that learn endlessly from the consequences of their own actions, in much the same way AlphaZero learnt the game of Go without studying any human matches. Why $1.1 billion at seed The size of the round is unusual even by the inflated standards of the 2026 AI capital cycle. Two factors appear to explain it. First, frontier reinforcement learning at the scale Ineffable describes is computationally extraordinarily expensive: the company will need to operate vast simulation environments and train very large models against them, an undertaking that consumes capital at a rate closer to physical R&D than to traditional software. Second, the round signals a strategic move by Europe’s investor and policy ecosystems to retain the most ambitious AI researchers on the continent. The presence of the UK Sovereign AI Fund alongside Sequoia, Lightspeed and Nvidia is the clearest expression of that intent. The British government has publicly framed the investment as a bet on breakthrough AI that “can discover new knowledge”, positioning the country as a willing co-investor in domestic frontier laboratories. For Ineffable, the implication is access not only to capital but to compute, regulatory engagement and the still-resilient academic talent base around UCL, Oxford, Cambridge and Imperial. Founder pledge of historic scale Alongside the funding announcement, Silver disclosed that he is committing 100 per cent of any personal proceeds from his Ineffable equity to charity via the Founders Pledge network — described by the organisation as the largest pledge in its history. At the round’s $5.1 billion valuation, that commitment could ultimately exceed several billion dollars if the company succeeds. It is a meaningful gesture in a sector where the reputational stakes around concentrated AI wealth are escalating, and one likely to be referenced in subsequent founder-led commitments. Implications for the European AI landscape Ineffable’s emergence reshapes the European AI map in three concrete ways. It establishes London as the home of the continent’s largest-ever seed-stage company, complicating Paris’s recent narrative of frontier-AI primacy after Mistral’s earlier rounds. It validates a thesis — that reinforcement learning, not transformer scaling, is the next frontier — that has lately been losing capital share to language-model incumbents. And it confirms that the UK government is now willing to act as a balance-sheet co-investor in domestic AI laboratories, a posture much closer to the French model than to the predominantly grant-based regimes elsewhere in Europe. The execution risk is non-trivial. 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