"Who owns the land?" is a central question because space is a resource as vital as air and water. Today, however, data ownership has become just as relevant as the question of land ownership in the context of urban planning. Technology companies are entering the field of architecture with algorithm-driven planning methods and massive investments in infrastructures and smart cities. In their technocratic vision, citizens become users, architecture becomes an instrument of statistics, and concepts such as the city and society become mere "algorithmic assemblages." This issue, co-edited by ARCH+, Arno Brandlhuber, and Olaf Grawert of station+/ETH Zurich, discusses the politics of space and data; the real and virtual assets of the city of the future.

The incessant trend to throw away rather than to repair, demolish rather than refurbish has been a topic of discussion and criticism for years-at the same time, resource consumption and the waste continue to increase. To counteract this trend, students at the University of Applied Sciences in Munich and ETH Zurich have been developing sustainable and imaginative concepts for repairing a wide variety of objects, applying them both manually and by using digital techniques such as 3D printing. Beyond restoration, many projects aim to further develop and improve the repaired objects constructively, materially, or even in terms of design, lending them new value. This publication presents a wide variety of approaches and projects, complemented by essays by notable personalities from the fields of architecture, preservation, materials science, design, manufacturing, and craftsmanship.

Constant change is what marks the history of the European city. Over centuries, architecture's reactions to social disruptions-natural disaster, plague, or war-have fashioned the city into an engine of civilization. And bound up with this has been the promise of economic independence, social cohesion, and individual freedom. Now fundamental challenges, such as climate change, are bringing cities face to face with new transformations that call into question the continuity and sustainability of the ethical foundations underpinning urban ways of life. Bold and decisive steps are needed. How far can urban planning, landscape planning, and architecture foster the vital processes of change? How can the city offset possible losses caused by altered lifestyles, integrate new technologies, or rehearse new forms of behaviour and ultimately sublimate them into a functioning culture? In this volume, the members of the Architecture Section of the Akademie der Kunste Berlin and their invited guests from all over Europe introduce their positions by means of projects, visions, and manifestos. Essays by selected authors with different viewpoints supplement the practical discourse. Published by Tim Rieniets, Matthias Sauerbruch, and Joern Walter on behalf of the Akademie der Kunste, Berlin. With a photoessay by Erik-Jan Ouwerkerk.