CAAD Futures is a biennial Conference that aims to promote the advancement of Computer Aided Architectural Design in the service of those concerned with the quality of the built environment. The conferences are organised under the auspices of the CAAD Futures Foundation. The series of conferences started in 1985 in Delft, and has since travelled to Eindhoven, Boston, Zurich, Pittsburgh, Singapore, Munich, Atlanta and Tainan. The book contains papers selected from the 11th CAAD Futures conference which took place at Vienna University of Technology, June 20-22, 2005. The papers in this book cover a wide range of subjects and provide an excellent overview of the state-of-the-art in research on Computer Aided Architectural Design.