The Spoorzone in Delft is an area that was once occupied by the railway. The historic city grew organically, and later expanded around this transportation hub. Nowadays, the railway is situated in a tunnel underground. Leaving behind a substantial vacant plot in the middle of the city waiting to be reterritorialized. On one side is the historic city centre and on the other many neighbourhoods with their own identities. The Spoorzone finds itself in between territories; in between old and new, west and east, city and neighbourhoods. Given the fact that we live in a rapid changing society, the question arises how to develop a substantial plot in the city in a durable way. How to approach a design project on a site that once was a border in between territories ànd is able to keep up with rapid changes that characterize our time. This project proposes a shift in thinking to approach the design as a dynamic process rather than a final image. This research and corresponding design project is about thinking in territories. The goal of the project is to see architecture as dynamic. The main question therefore reads as follows: ‘How can an architect change its view on architecture from static to dynamic, and become able to trigger a perpetual re-assembling of space, by using territoriality as a working concept?’ The answer to this question will be explored by two ways of working. A theoretical and practical one. The practical part will be examined in the design project. The research paper is the theoretical part and consist of a literature review in the field of philosophy (focussing on Deleuze and Guattari) and design studies. Concepts as territory and in-between are examined in detail to gain a basic understanding and help the reader to approach architecture from a different angle. The main finding is that a building can be approached as subject producing. Encounters between the subject and the building are affective and determine what a body can do and what it can undergo. By thinking in territories, it is possible to discover affects and to open up multiple possible outcomes of encounters between subject and physical environment. By being able to see architecture as dynamic, a building can be seen as durable, because of being able to trigger a perpetual re-assembling of use of a space. The design project proposes a living room for the city that is able to keep up with the rapid changing desires of our time and, additionally bridges the gap two between the different sides of Delft, inviting people to overcome this border. The design is based on a simple structure with set of frames. Variation of this structure are make up the whole building. The frames will affect its users, giving it limits to move in between. However can be can also be affected upon, keeping it open to future activities. The project is organized along a structure that moves from explaining the tiniest ingredients of a territory to the reassembling in new circumstances. This is done by breaking down, including and excluding, and finally re-assembling the components of a territory. The transition from research to the design will be made by constantly following these steps and evaluating them.