"The world - at least in Europe - is built. The future lies in using what we have. Evolution rather than revolution has always been more beneficial for people. Many believe that this is now increasingly true for the built environment. Goods that cannot be reproduced are becoming scarce and the economy is showing us ways to use the existing stock.a discussion of value without history is worthless."

With this thematic challenge, architects and engineers, scientists and practitioners, philosophers and industrialists exchanged ideas in an interdisciplinary discourse in May 2011 in the Kuppelsaal of the Vienna University of Technology on the occasion of the 20th International Industrial Building Seminar of the Chair of Industrial Building and Interdisciplinary Planning. This book attempts to document the spontaneous creativity of the participants and their contributions. In doing so, it comes as a surprise that the topic of the use of existing buildings is full of life and is by no means limited to the built environment. At a time when the concept of sustainability is used more than inflationarily, it is good to look for solid ground under one's feet and to find it in existing structures.