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Benjamin CONSTANT, a graduate of IÉSEG’s class of 1996, is now a partner at Neo-Eco and president of NeoCem, an industrial start-up tackling one of today’s greatest challenges: massively decarbonizing the construction sector through low-carbon cement. After a successful first phase in the corporate world, he chose to become an impact entrepreneur. As the mentor for IÉSEG Class of 2023, he shares insights about his journey, his convictions, and the importance of combining purpose, economic performance, and commitment.

Benjamin Constant, why did you choose impact entrepreneurship after a successful corporate career?

I think I’ve always had an entrepreneurial spirit. When I was a student at IÉSEG, I nearly dropped out to launch a tech start-up. Back then, I was a real geek, fascinated by the organization around people and data. But I wasn’t ready to take the plunge yet.

The desire to start something on my own came back much later, around what people call the “midlife crisis.” I had reached my career goals, held leadership roles in major international companies in textile and creative industries, and lived in ten countries (Spain, South America, Sweden…). The search for meaning became my priority.

I have always been deeply environmentally conscious: we don’t live in isolation on this planet, which feels smaller every day. More importantly, we need to recognize that those of us living in developed Western societies enjoy some of the best living conditions—and are also among the biggest polluters. We therefore have a real responsibility towards others and the planet.

After 20 years leading companies, I felt the need to find deeper meaning and contribute professionally to projects aligned with my core values. This process took time; it didn’t happen overnight. Eventually, I resigned to pursue projects whose purpose, values, and vision resonated with me. Over two years, I supported about ten such projects, until I met Christophe DEBOFFE, who inspired me to join Neo-Eco.

Could you tell us more about Neo-Eco and NeoCem?

Neo-Eco is an engineering firm specializing in circular economy solutions, focused primarily on materials. Why materials? Because they’re tangible, measurable, and concrete. At the end of any project, we can objectively calculate the impact in terms of tons of material reused or recovered. This helps avoid greenwashing and supports companies in reducing their environmental footprint while improving profitability. In fact, most of our projects optimize resource use and reduce costs.

Our team at Neo-Eco is fully committed to deploying circular economy solutions. Our vision is beautifully simple: a world without waste. Didn’t we all learn in school that “nothing is lost, nothing is created, everything is transformed”? We are, in a way, disciples of Lavoisier—finding ways to shift from a linear economy that consumes disposable materials to a circular economy where resources are reused.

We innovate constantly, relying on partnerships with universities and private companies. This approach has enabled Neo-Eco to launch over 23 start-ups. I now lead one of them: NeoCem, a project aimed at decarbonizing the construction industry.

Every year, 40 billion tons of concrete are used worldwide—that’s 5 tons per person! Concrete accounts for 8% of global CO₂ emissions, 90% of which come from cement. In France, we consume 17 million tons of cement annually; in Europe, over 200 million tons. These are staggering volumes.

NeoCem has developed an innovative solution to reduce these emissions by 90%. It uses clays excavated during construction work, which we calcine. These calcined clays replace a large part of traditional cement. They provide the same performance, at a lower cost, while being low-carbon. This removes all barriers to sustainable construction.

Our R&D began in 2017. Thanks to support from the Société du Grand Paris, we accelerated development in 2018. In December 2022, NeoCem was awarded the “France 2030” prize, the government’s program to support green industrial solutions. After securing a site 30 km north of Paris, obtaining environmental permits, and raising funds, we started building the first production facility in October 2023. Production will begin in June 2025!

What makes an impact entrepreneurship project successful?

Every story is unique. But above all, you have to truly want to start. The saying “where there’s a will, there’s a way” fits perfectly with entrepreneurship. You also have to embody strong values, so much so that they become the foundation of your project.

Then, like any venture, you have to dare to take the leap. For some, it comes naturally; for others, it’s a rebellion, a calling, or simply a game. For me, I always wanted to be an entrepreneur, but I didn’t dare right away. I hesitated a lot. I needed reassurance, to know I was capable, and to have enough financial security to give myself time to try, fail, and try again. We all have different security needs.

If you don’t know where to start, join a team—that’s what I did with Neo-Eco and Christophe. Before even knowing the exact project, we shared the desire to create and had common values. From there, the committed and autonomous Neo-Eco team shaped the momentum. Our success comes primarily from a group of professionals sharing strong values and ambition around the circular economy. This enables decentralized decision-making, where long-term vision coexists with short-term economic realities, as in any business.

Is profitability necessary for an impact entrepreneur?

It’s not just necessary—it’s essential. Without economic performance, there can be no real impact. These two aspects are deeply connected. Without financial health, an entrepreneur can’t grow, innovate, or scale their project—and therefore can’t make a significant impact on the planet.

Similarly, being an “impact” company alone isn’t enough to attract funding and convince investors. Investors care about your story, your purpose, and your values, but they primarily analyze your financial strength and performance.

Finally, the impact dimension often boosts economic performance by unlocking various regulatory incentives available for environmental protection. There are many; we need to use them!

Are you the same entrepreneur at 20 and 40?

I don’t think it’s a question of age but of personality. Everyone has a different appetite for risk and different expectations. For example, before becoming an entrepreneur, I needed to succeed in my career and have the financial means to live comfortably. Once these needs were met, I knew I could start a venture calmly. I wish I had done it earlier—I already wanted to as a student—but it only materialized later.

At 40, you have more responsibilities, especially family ones, but also more resources. At 20, you’re free, more carefree, with more time to bounce back from failure.

In my case, my desire to act grew into a sense of urgency and strong environmental concern, pushing me to start a business with a positive impact.

What advice would you give to students or future entrepreneurs?

My best advice? “Know thyself,” as Socrates said. Find your core values, listen to your desires, discover the causes worth fighting for, and make peace with your doubts.

Not everyone is meant to be an entrepreneur today—but maybe tomorrow? If the desire is there, stay alert, work to give yourself the chance, and seize the moment when it comes.

That’s exactly what happened to me: I had the desire, then found the right team and the project that spoke to me. In France, we have many safety nets that limit risks—we should use them. The worst thing that can happen isn’t failure; it’s living with the regret of never having dared.

We each have about 30,000 days to live—so let’s use them to experiment, create, and write the story of an exciting life. And at IÉSEG, we got excellent preparation to maximize our chances of success!