Stef Feyen
Expertise
He specifically focuses on energy, sustainability and, more broadly, on partnerships between the private and public sectors. With a recognised expertise in public procurement, public-private cooperation and regulated markets, he can rely on extensive experience in a myriad of (regulated) sectors, including healthcare, defence and security and the energy sector writ large.
He combines in‑depth sector knowledge with a strong understanding of the broader legal and policy landscape, which bolsters his guidance through complex regulatory frameworks, including novel frameworks associated with quick shifts in the energy and industrial landscape.
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Work highlights
Some of Stef’s recent work highlights include assisting:
- Engie Electrabel on the Belgian capacity mechanism for electricity, the support scheme designed to safeguard Belgium’s security of supply (including litigation before the Market Court on this topic);
- Goodman on the development of datacentres in the face of increasing flexibility needs;
- Biostoom Beringen and Oostende on transactions pertaining to heat grids and related project development aspects;
- Vlaamse Nutsregulator (vnr) and Brugel, whilst representing them on complex litigation regarding electricity balancing market design and in advisory work on prioritization in the context of flexible connections;
- Altrio on navigating the healthcare regulatory landscape to support growth and cooperation;
- Aevex on how to structure defence cooperation within the Belgian, EU and NATO regulatory framework.
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What others say
Stef Feyen is recognised by The Legal 500 (2026) as a next generation energy partner. He is further praised as someone who “stands out as very knowledgeable on energy topics in the widest sense” and for combining contentious and advisory expertise, particularly in relation to grid regulation and the energy transition.
Clients describe his team in The Legal 500 (2023) as being "very responsive with high quality legal advice which is pragmatic and to the point", adding "it is a real pleasure working with this team. Particular mentions for Jens Mosselmans, who is very responsive and to the point, and Stef Feyen, with his in-depth knowledge".
The team is praised in Chambers (2023) for its "very comprehensive knowledge and experience in Belgian constitutional and administrative law" and confirms that the team is "able to deliver support in a short period of time".
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Ancillary function
From 2010 to 2017, Stef was a Fellow of the Research Foundation – Flanders (FWO). In 2015, he was a guest PhD researcher at New York University. Between 2010 and 2022, he served as a teaching assistant at KU Leuven and Université Saint‑Louis, and since 2022 he has been a research associate at Université Saint‑Louis.
Stef is a doctoral researcher affiliated with the Ius Commune Research School (Maastricht University) and is an Honorary Fulbright Scholar (2010) and BAEF Fellow (2009).
In 2024, he was elected by Belgian Parliament as a substitute board member of the Federal Institute of Human Rights for his broad background in constitutional and human rights law. For several years, Stef has also been an active member of NautaDutilh’s Diversity & Inclusion Committee, contributing to the development and implementation of the Brussels office’s diversity policy.
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Qualifications
In 2009, Stef obtained a double master’s degree in law and political science from KU Leuven. He graduated from Harvard Law School in 2010 (LL.M.), pursued a doctoral dissertation until 2017, and is completing an additional master’s degree in corporate law (KU Leuven) in 2026.
