"For young children, sensory-motor activities constitute a privileged way of appropriating outdoor living spares. The methods of observation used here are similar to the so-called 'clinical" approach. In the case of the roof gardens at MANTES-LA-JOLIE, the analysis of the expe riences of the residents following observation of their behaviour enabled us to bring to light some phenomena of appropriation which were taken note of in the plans for redevelopment. At TILlS, the observations were carried nut in a framework of a higher than average quality as far as the organization of space and the treatment of outdoor areas were concerned. From this came the choice of examples relevant to the appropriation of minerals and vegetals. With the necessary adaptations, the procedure followed can be applied equally to the rehabilitation of old areas as to the drawing up of an operations report, when the aim is more or less normative."