DEVELOPMENT OF DESIGN CRITERIA TO IMPROVE AESTHETIC APPRECIATION OF EXTENSIVE GREEN ROOFS (EGR)

Books, reports, and articles have discussed the aesthetic as well as psychological benefits of implementing green roofs. These claims are based on studies which show that scenes or landscapes containing natural elements (usually vegetation) are either preferred over urban scenes or landscape devoid of these elements; or that they are more psychologically beneficial. The authors submit that these results cannot actually be readily applied to extensive green roofs (EGR), for two reasons. 1. It is possible that EGR would not be perceived as natural elements but as infrastructure, as part of buildings. 2. The appearance of EGR is very different from aesthetically valued nature scenes. Studies involving the preference between nature-containing scenes have distinguished between scene content (types of plants) and scene structure or spatial organization. Both have been found to influence aesthetic appreciation. Sanitary or seasonal conditions of the vegetation, soil coverage and colour have also been found to have an impact on preferences. In terms of spatial organization, preferred or restorative landscapes have been mostly described as park-like settings of smooth grass and trees. Studies indicate that the quality of the urban environment as well as the views could impact on preferences or aesthetic appreciation. Based on a critical review of research results, the authors will propose design criteria to increase aesthetic appreciation of EGR. The possible contribution of familiarity and knowledge to the enhancement of aesthetic appreciation of EGR will also be discussed.