In many Western countries, non-formal education has become increasingly recognized as a valuable addition to the traditional educational system. In recent years, a special form of non-formal student laboratories (Schülerlabor) has emerged in Germany to promote primary and secondary practical science learning. This paper describes a developmental project on Schülerlabor learning environments for all students with a particular focus on sustainability education in the context of chemistry-related topics. The goal of reaching all students puts intentional pressure on the development process of learning environments. It forces the Schülerlabors to create a detailed model of differentiation, which can reach all learners of different interests and abilities. This also includes low-achievers and students who have disadvantaged educational biographies. In this sense, the structuring of non-formal learning environments simultaneously becomes a process of innovation with respect to both the curriculum and the teaching methods. In this paper, we present a corresponding model of differentiation and a specific example focusing on the learning about protecting and preserving metal objects in science education. Preliminary results and implications from the accompanying evaluation are also discussed.