‘Build impression rooms in which customers see how that ‘new’ second-hand couch looks in the living room! This way, you directly see what impact you reduce and how fun second-hand can be.’ With this idea, team Samen Groen Groeien won the National Hackathon Circular Economy 2025. Out of 13 other ideas, their solution for the challenge posed by bol and Het Goed was chosen as the winner by the jury during the Grand Finale on Friday, February 7th.
During the hackathon, over 400 students from all educational levels and from all over the Netherlands worked on a challenge from bol and Het Goed: ‘How can retailers encourage young people to choose circular consumer goods instead of buying new?’ Supported by inspiring sessions from climate optimist Maartje Bregman and Zero Waste expert Elisah Pals, ideas were refined into solutions that help retailers make circular goods more attractive to young people.
The Grande Finale
On Friday, during the Grand Finale, the best 13 teams pitched their ideas to a jury of experts. A great diversity of ideas, ranging from loyalty programs to circular pop-ups, provided bol and Het Goed with plenty to think about. An expert jury, consisting of Martijn Bijmolt (Het Goed), Bart Verhulst (bol), Derk Remmelink (Category & Trade Company), Mirella Soyer (Hogeschool Rotterdam), Kylan Cassee (Coolblue), Freddy Pelders (PreZero), and Huib Pasman (Johan Cruijff ArenA), ultimately selected one winner from all the ideas.
The winning idea
The jury faced a challenging decision. After thorough discussions, a winner was ultimately selected: ‘Samen Groen Groeien’, whose innovative solution impressed the judges with its creativity and potential to make an impact. The idea of the students was to make ‘impression rooms’ both in thrift stores and online. The physical impression rooms combine second-hand options into inspiring and warm sets of the sustainable alternatives, from which the consumer can mix and match. The rooms give the chance to see furniture combined instead of on itself. The online impression rooms show the reduced CO2-impact and lower price of second-hand alternatives.
"You immediately see what you save. This is easy for young people, and they are instantly engaging in circular and thus sustainable practices," said the winning students Gébin Meels, Max Kaelen, Janneke Soons, Milou Gorissen, and Bas Wulffraat from Zuyd University of Applied Sciences.
This idea stood out to the jury, because they achieved “to blur the line between a thrift store and a retailer.” By introducing the concept of impression rooms, the idea was brought to life in a practical and impactful way. The winners receive a voucher from Het Goed, a session with bol, Het Goed and The Category & Trade Company, and present their idea at the National Circular Economy Conference on March 20th to a larger audience.
2026 NHCE challenge
We also got a glimpse of the sixth edition of the National Hackathon Circular Economy during the Grand Finale: PreZero announced that they will shape with other partners next year's challenge together with the organization! Inspired by the Johan Cruijff ArenA as the venue for this year’s Grand Final, the challenge will focus on making events more circular.
Freddy Pelders (PreZero) explains: “We believe it’s incredibly important for students to get involved. That’s why we are partnering up with the National Hackathon, as we want to actively engage students on the way to a circular economy. They are the future.”
Thank you!
We’re looking back on a wonderful week. We’re amazed by the number of inspirational and innovative ideas that came forward during the week. Many thanks to all the involved students, teachers, educational institutions, partners, inspirers, and everyone else who contributed!
