Prospect-Refuge theory and the textile-block houses of Frank Lloyd Wright: An analysis of spatio-visual characteristics using isovists

Prospect-Refuge theory argues that human environmental preferences are attuned to seeking spaces that offer a balance of outlook and enclosure. The first and best-known architectural application of this theory was Hildebrand's proposition that the emotional power of Frank Lloyd Wright's architecture arises from a distinct pattern of spatial enclosure and outlook. Hildebrand presented Wright's textile-block houses as ideal examples of this prospect-refuge pattern, which he called the 'Wright Space". That argument has since been widely repeated and even used as a design formula in contemporary guides, but there is no quantitative evidence that its catalyst, the Wright Space, actually exists. Using isovist fields, this paper undertakes a computational and mathematical analysis of the spatio-visual properties of paths through five of Wright's textile-block houses. For each house a comprehensive two-dimensional analysis, supplemented with selected three-dimensional data, is used to derive ten measures of spatial properties with which to assess Hildebrand's application of Prospect-Refuge theory. Through this process the paper investigates whether the Wright Space exists, and if it conforms to the four key prospect-refuge related properties identified by Hildebrand. The paper concludes that some evidence exists to support the existence of the "Wright Space", however the strength and consistency of the pattern remains questionable. (C) 2014 Elsevier Ltd. All rights reserved.