A new Belgian steward-owned startup — how eXo membranes is building a company that's regenerative by design
What if building a better world wasn't just your product's mission — but the very DNA of how your company is structured? That's the question Rhea Verbeke and Laurent Hubert chose to answer when they founded eXo membranes.
eXo membranes is a KU Leuven spin-off on a bold mission: to purify the most challenging industrial water streams. Their epoxy-based membranes withstand extreme pH levels and harsh chemical cleaning that cause standard membranes to fail — breaking a costly cycle of downtime, early replacements, and unnecessary waste. In short, "No Stream Left Behind."
But the technology is only half the story. From day one, Rhea and Laurent asked themselves a harder question: how do we make the company itself regenerative — not just the product?
Why steward-ownership?
Three questions drove the founders to steward-ownership as the only logical answer:
1 Avoiding exit-driven logic
How do you ensure a mission-driven company never ends up sold to the highest bidder — regardless of what that means for the mission?
2 Guaranteeing long-term continuity
How do you protect the company from short-term shareholder pressure or absentee ownership that has nothing to do with the work?
3 Keeping decisions mission-aligned
How do you build structures that ensure profit serves the purpose — always — rather than the other way around?
Steward-ownership answers all three. By separating voting rights from financial rights, the model ensures that those closest to the mission hold the steering wheel — while investors can still be fairly rewarded for the capital they contribute. Purpose is protected by design, not by goodwill alone.
Three milestones that matter for the movement
1st company to issue a Golden Share to the Belgian Golden Share Foundation
€700K raised in a pre-seed round — fully within steward-owned principles
7+ other Belgian companies set to follow with their own Golden Share
eXo's launch is more than one company's milestone. By becoming the first to effectively issue a Golden Share to the Belgian Golden Share Foundation, they've created a living proof-of-concept — and opened the doors of steward-owned-aligned finance for other early-stage Belgian start-ups.
An Alice in Wonderland kind of journey
Getting here wasn't straightforward. Rhea and Laurent were a very early-stage deep-tech start-up navigating ownership structures, investment models, and legal frameworks that most founders never have to think about. Rhea in particular dove in with imagination and persistence — questioning existing patterns around money, power, and authority, and daring to choose differently.
She fell in love with steward-ownership not as an abstract principle, but as a practical, meaningful path. And she persevered — even when the road felt counterintuitive.
“Their story is the ultimate answer to one of steward-ownership’s most important questions: “What is enough?””
eXo membranes is proof that a start-up can build both a regenerative product and a regenerative company — from the very beginning. We are proud to have guided Rhea and Laurent through this journey, and certain that many will follow the path they've set in 2026.
Watch this space.