Abstract: This paper describes how mixed reality (MR) technology is applied in the urban renewal process to help mixed groups of stakeholders collaboratively construct, explore and discuss their vision of a particular urban project on site. It introduces the MR Tent, a physical enclosing for a collection of MR prototyping tools. We report findings from the most recent participatory workshop with users on an urban planning site concerning the interaction space, views, tangibility and representational formats.