Ecology in developmental psychology is strongly associated with Bronfenbrenner’s model of the ecology of child development focusing on the interconnectedness between different settings and systems, both physical and social. His multilevel approach stimulated numerous studies about complex influences on child development, including methodological innovations of multi-level analysis. However, the “ecology” has been introduced into psychology before, focusing on different aspects of the interrelationship between people and their environment. Lewin’s field theoretical approach emphasized the (subjective) experience of places and objects (lifespace), and only his “psychological ecology” drew attention to facts that follow nonpsychological rules but nevertheless have an influence on a person’s lifespace. R. Barker, with his “ecological psychology”, focused almost exclusively on these extra-individual (physical and social) features of settings that are shaping (rule-oriented or scripted) behavior patterns of individuals. Bronfenbrenner from the very beginning recognized both, objective and active, growing child and ever-changing multi-level environments, later extending his approach into a bio-ecological one. Yet another conception seems adequate to address the interdependencies between children and their environment. The concept of ”appropriation”, originating from the Russian school of psychology (Vygotsky, Luria etc) points to the sociocultural and interpersonal context of all appropriation. Human mental and physical activities make the world a human habitat, and in turn arouse, incite and afford human activities. Ever since “appropriation of space” became the theme of one of the first IAPS conferences (Strasbourg 1976 ), C.F. Graumann and I developed the concept and proposed modes of appropriation. I will report on a recent doctoral thesis by Andrea Petmecky who operationalized some of these modalities and developed new methods to study the appropriation of preschool settings by 5 to 6 year old children (via cognitive and verbal responses), looking at different pedagogical principles (as an example of the macro-system), as they become manifest in the built environment and the behavior of the care takers. Results demonstrate interesting interactions between the quality of the architecture, the pedagogical principles and the more or less active appropriation of children and educators.