This article reports seven new, original findings, based on 4 experiments, 56 environmental scenes, and 71 participants, on how the factors of area over which one could walk (boundary height, boundary porosity, and boundary proximity) influence perceived spaciousness or enclosure. Perceived spaciousness was most strongly related by the area over which one could walk. Enclosure was most strongly related to boundary height. Proximate boundaries had stronger effects on perceived enclosure than did distal boundaries. Results were highly reproducible over vastly different environmental venues, indicating that the research protocols worked very well.