Restorative Environmental Design for Densifying Cities

Abstract

The urban population around the world is growing rapidly. Although increasing urbanization has positive aspects, it has also raised concerns about environmental, economic and social sustainability. As response, some design and planning solutions emphasize greater densification of urban areas. Research has however not been able to show that urban density enhances sustainability in a consistent manner. One possible explanation might be the neglect of psychological factors within the compact city practice. Restorative environmental design (RED) that builds in part on theory and empirical research concerned with restorative environments is one approach to addressing this problem. To date, however, the empirical results behind RED as applied to urban densification are quite limited, and the purpose of this thesis work is to provide more empirical substance to reinforce the foundation of RED for use in this context. This work is based on four papers. The first paper is an introduction to the restoration perspective on human-environment relations in general and to research on environmental supports for psychological restoration more specifically. It provides a starting point for the empirical work in this thesis by identifying some specific research gaps with regard to the restorative potential of urban environments. The three remaining papers report a sequence of empirical studies that focus on specific physical components and characteristics that affect the restorative potential of urban streetscapes. Taking guidance from the preference literature when choosing relevant characteristics, the first two of the remaining papers report the results of studies that used digitally created static images to present streetscapes in which different characteristics had been systematically manipulated. Aggregate ratings for the respective image sets were obtained from adult Icelanders through an internet-based procedure. The results of multiple-mediator regression analyses found architectural variation (presented as entropy), number of street trees, their arrangement along the street, presence of flowers, and presence of grass to positively affect ratings of the likelihood of restoration, with the effects mediated by one or both of the restorative quality variables being away and fascination. The results also demonstrated a negative effect of building height on judgments of restoration likelihood, as mediated by a reduced sense of being away. In a third study, reported in the fourth paper, ratings of restoration likelihood obtained in the earlier empirical studies were found to predict actual restoration experienced by members of a separate sample. Two three-dimensional interactive virtual neighbourhoods were constructed from streetscapes that in the two previous studies had differed in term of restoration likelihood. Participants who “walked” through the low restoration likelihood neighbourhood showed a negative shift in affective balance while those who navigated through the higher restoration likelihood neighbourhood showed a positive shift in affective balance. This effect became stronger after adjustment for the participants’ own perceptions of restorative quality (being away and fascination) in the assigned streetscape. The results of this dissertation work show that the restorative potential of residential urban environments depends on specific architectural components and design characteristics, which indicates the relevance of RED for densifying cities. The results provide guidance for the design of more psychologically sustainable urban residential environments. The studies also demonstrate strategies for using digital imaging and virtual technologies in pursuing the further research that is needed in this area to strengthen the empirical foundations of RED. Finally, this work encourages authorities and practitioners to apply a restoration perspective in their efforts to create urban environments that are sustainable not only in ecologic terms, but also in terms of basic human needs.