Effects of boundary height and horizontal size within boundary on perceived enclosure

The permeability theory of environmental design predicts that perceived enclosure will be more strongly related to boundary properties such as height as opposed to the size of a horizontal area within a boundary. An experiment on perceived enclosure, provided by 24 participants on 12 spaces in a park, indicated that enclosure correlated at .85 with boundary height and -.60 with horizontal area. These results were as predicted by permeability theory.