Living roof preference is influenced by plant characteristics and diversity

Living, or green roofs, are increasingly built in cities for their environmental benefits, however there is little evidence about how to maximise their aesthetic appeal. Because preferences for landscapes can be determined by vegetation characteristics we surveyed the preferences of 274 Australian office workers using 40 living roof images which systematically manipulated plant life-form, foliage colour, flowering, diversity and height. These preferences were compared to those for a bare concrete roof. The potential restorativeness of the most preferred living roof and the concrete roof were also assessed. Results showed that all living roofs were preferred over the concrete roof; however preferences differed according to vegetation characteristics. The most preferred and restorative living roof had taller, green, grassy and flowering vegetation, while lower-growing red succulent vegetation was least preferred. Participants preferred a productive landscape, with green foliage and flowering consistently preferred. Participants with a stronger connection to nature consistently assigned higher preferences to taller, compared to lower-growing, vegetation. Increasing diversity was associated with higher preferences overall, but decreasing preferences for highly preferred vegetation. This research makes an important contribution to understanding employee preferences in the unique context of urban living roof landscapes. (C) 2013 Elsevier B.V. All rights reserved.