For my thesis project, I have chosen to explore the exaptation of a vacant office building doomed to be demolished in Stockholm into a residential tower. This project’s focus is the investigation of the reusability of our existing built environment in a sustainable way together with diverse collective living concepts and a comparison of the value added from a deconstruction, reuse and an environmentally sound concept versus a full demolition and subsequent new construction.The paramount challenges we are facing are the changing climate and limitation of natural resources. We have to address this issue by rethinking our societal and habitational models; the way we live, how we inhabit space, how do we use resources and consume goods and especially how do we design and build our cities.