The present volume gathers for the first time the writings that Xenakis, one of the most outstanding figures of the European culture of second half of century XX, dedicated to the architecture and to the relations between this discipline and the music. The examination of his personal archives has revealed, among other things, the richness of this material - articles, letters, lectures, theoretical writings, programmatic reflections - that completes his own sketches and architectural projects. The originals of Xenakis (presented and commented by Sharon Kanach) are articulated in four sections: "The years Le Corbusier", "The cosmic city and other writings", "Xenakis, independent architect" and "The Politopos". The documentation is completed with an illustrated critical index of the set of projects and work done (Sven Sterken), an extensive bibliography (Makis Solomos) and a chronological chart.