Since the 'sixties anxiety about the future of mankind has led to a number of major publications on the world's vital problems and the relationship be tween them, the best known being the reports to the Club of Rome. This study of the problems of providing living accommodation for a rapid ly growing world population, taking into account the limits that must be set to this growth, was started in 1973 at the Academy of Architecture and Erasmus University, Rotterdam, and testifies to the same anxiety. Inhabiting the Earth as a Finite World is the impressive result of a study of the consequences of meeting the just demand for good accommodation for all the earth's in habitants, worked out with the aid of a world model and a number of case studies. The value of models, especially very complex ones, is at present debatable. Nevertheless, they can often cast light on complex situations. The simplified form of the real situation, which every model in fact is, allows certain impli cations of decisions to be discerned and taken into account in planning. The comparison of the results of the study with the design process is a clear example of this.