To whom does the city belong? Who is allowed to design the city? What defines a successful cooperation between civil society and the institutional planning of urban spaces? In landscape architecture, design and planning theory, emancipatory spatial practices in the production of the urban are discussed under the term appropriation. The present work is dedicated to the paradoxical relationship between the planning and design professions and informal appropriation practices: Integrating a civil society willing to participate productively and creatively in the production of urban open spaces seems to remain difficult, despite a multitude of possible tools. First, a theoretical part discusses appropriation in the context of relational concepts of space, qualifying as emancipatory spatial practices. The debate surrounding the planning and design of the Gleisdreieck Park in Berlin from 2005 onwards is then analyzed as part of a qualitative case study inspired by the “toolbox” of discourse analysis. Based on the detailed interpretation of sources consisting of text fragments and image material as well as interviews with relevant actors involved, the thesis discusses the creative and democratic potential of an appropriation-friendly design culture.