RE-AUCTION is a toolbox developed for children between 9 and 13 years old and the pedagogues of the Klubben Musvagevej, which is part of the UNGI Aarhus collaboration project. The toolbox contains relevant tools that enable children to plan and host their auctions with the pedagogue’s guidance. The goal is to encourage children to be part of the sustainable changing process by redefining the notion of waste. Re-auction uses a playful approach to encourage children to waste less by exchanging more with their unwanted belongings and eventually creating healthier consumption habits.