Public Participation encounters great challenges in the domain of urban design concerning decision making and citizens’ appropriation of a future place. Many tools and methods have been proposed to ease the participation process. In this paper we are targeting artefacts used in face-to-face workshops, in which citizens are asked to make design proposals for a public space. We claim that current state of the art can be improved (i) by better articulating digital artefacts with participatory processes and (ii) by providing interfaces that enhance citizen’s spatial awareness and comprehension as well as collective creativity in urban design projects. We present the design and prototyping of an interactive virtual environment that follow the design-science research guidelines.