Densification of urban areas set new challenges for public participation, which is illustrated in our Finnish case study. We organized a new kind of participatory event, where we took an office container to the planning area for 10 days in September 2014 and welcomed people to participate. We invited experts from the city of Tampere to answer to questions in their area of expertise, such as traffic, green areas and parking policy. The locality of the event turned out to be a crucial success factor, allowing the issues to be discussed on-site. We interpret the event as boundary interaction, where different boundary objects were used to facilitate communication and the role of researchers was positioned as brokers. We conclude how the method allowed ‘publics’ to develop their understanding of the central issues and how the method could be further developed for collaborative planning.
