The PhD thesis ROOM FOR RAIN studies how the design of urban streets may be able to simultaneously mitigate the effects of stormwater events, enhance the perceived sensuous and social qualities of streetscapes, as well as support natural ecologies in the city. One of the most critical global challenges at the moment is the changing climate of our planet. As a consequence of climate change, we will experience a higher frequency of heavy rain events in the very near future in areas like Europe and North America (IPCC 2014c). Accordingly, in order to mitigate these negative effects of climate change the design of our cities needs to respond to the changed weather patterns. One of the larger challenges of these climate mitigation strategies will be to transport the stormwater to green areas and water bodies, where the water is less damaging. The urban street-fabric comprises an obvious tissue for transporting and delaying the stormwater, and therefore a large number of existing streets in dense urban settings will undergo significant and important changes in the coming years. These changes will inevitably affect the use of streets and their role as infrastructures and everyday urban public spaces in the city. However, concurrently, the future retrofitting of streets also comprises a unique opportunity for unfolding the potential of the everyday street as a liveable urban space that supports natural ecologies in the city. For many years streets have been neglected as urban spaces despite the fact that these are the public spaces that we are in most contact within our everyday life. The streets are the real lived public spaces of the city, where we fleetingly pass by a stranger or bump into an old friend. At the same time, the streets also encompass an important potential for supporting natural ecologies as they cover a large percentage of the total land area of cities and furthermore form urban corridors through which natural systems may spread and evolve. Partly as a consequence of the aforementioned challenges and potentials a new international hybrid discourse linking the three discourses of landscape-based stormwater management, urban nature and liveable streets together, is gradually emerging. This hybrid discourse fuses methods for managing heavy rain-events with an environmental awareness and an attention around the human dimension in the city. The important potential of this hybrid discourse is its ability to manage stormwater events, to support a more environmentally sustainable future and to improve the sensuous and social qualities of urban streets. However, the hybrid discourse predominantly only exists in a future, potential and virtual form and the few realized examples have been implemented in relatively wide streets or in new-build areas. Thus, there is a lack of knowledge concerning how to implement the solutions in existing streets in dense urban settings. Furthermore, there is a missing theorization of the possible conceptual implications of the hybrid discourse as well as the spatial potentials and consequences that the various design-solutions of the hybrid discourse may comprise. With point of departure in Copenhagen Cloudburst Plan, the scope of this PhD thesis is to critically construct a conceptual model along with spatial principles that can inform retrofitting processes in existing streets in dense urban settings in relation to an increased frequency of stormwater events. The PhD thesis, therefore, synthesizes knowledge about landscape-based stormwater management, urban nature and liveable streets. The study revolves around the idea that landscape-form and city-form could be united into a coherent thinking. My hypothesis is that: The spectrum of possible solutions for enhancing sensuous and social qualities as well as for supporting natural ecologies in streets through landscape-based stormwater management has not been fully explored. The reason that underlies this unexplored field of solutions is a not yet articulated operational vocabulary for speaking about the street as ecology and as bodily perceived space. Referring to Wolfgang Jonas’ suggested modes of observation in relation to design research (Jonas 2012), the research method of the PhD thesis is based on a combination of research about design, research through design and research for design. The method, therefore, varies between theoretical studies and design studies continuously informing each other. The theoretical studies are accumulating and discussing existing knowledge about the subject of study, whereas the design studies synthesize these different traces of knowledge in a consistent form. The empirical material spans from literature reviews, archive material, visited reference projects to workshops, interviews and design proposals. The study offers an analytical and a design-oriented perspective on the possible potentials and implications of the landscape-based stormwater management in dense urban streetscapes. I propose that the garden comprises an operational qualitative model for the city – both as approach and as metaphor - for understanding the street as a meeting between body and landscape. In this proposed garden-model both the ecologies of nature and the ecologies of urbanism are regarded as integral ecologies of the urban spaces. The findings of the PhD thesis point towards that landscape-based stormwater management both entails an important potential for upgrading the urban streets as sensuous and social spaces; however, the method simultaneously comprises quite dramatic spatial implications for the street profile. This underlines the importance of a conscious and well-considered approach to the sensuous and social consequences and potentials related to the implementation of landscape-based stormwater management in streets.