Social innovation entails new services, products, practices that address issues of social and environmental sustainability. In the last years there has been a growing interest of how design can be at play in supporting the flourishing and development of social innovation. What is the contribution that design approaches can offer to social innovation? And what are the limits of such approaches? And what may the role of the designer be in such projects? These questions will be discussed in relation to the development of the co-production project ReTuren, an upcycling station in Malmö.