Attitudes and aesthetic reactions toward green roofs in the Northeastern United States

• Overall attitudes and aesthetic reactions to green roofs are positive.
• More negative aesthetic reactions are associated with a sense of messiness.
• Stoloniferous grass dominated green roofs are less well appreciated aesthetically than sedum or mixed perennial dominated green roofs.
• Attitudes and aesthetic reactions to green roofs are positively correlated with one another.

Green roofs may provide environmental, aesthetic, and social benefits. Their environmental benefits have been the subject of considerable research in the past decade; the aesthetic and social aspects, however, have received less attention. Some authors have questioned the visual appeal of some green roof designs. Nonetheless, little research has examined aesthetic reactions toward green roofs or attitudes concerning them. We conducted visitor surveys at seven green roofs in the Northeastern US to assess visitors’ aesthetic reactions to different types of green roofs, determine general attitudes toward green roofs, and assess values concerning benefits and costs associated with them. Attitudes toward green roofs were positive with higher importance being placed on green roof benefits than costs. Aesthetic reactions were, in general, positive. Aesthetic reactions to roofs dominated by stoloniferous grasses were more negative than to either sedum-dominated or mixed perennial roofs. Principle component analysis showed that negative aesthetic reactions were associated primarily with a perception of messiness. Furthermore, respondents felt that the grass-dominated roofs blended less well with the building and surrounding landscape. Aesthetic reactions were positively correlated with attitudes and importance placed on the benefits of green roofs. Positive visitor reactions to sedum-dominated extensive roofs is a favorable result for the green roof industry as these are the most common type of green roof and this suggests that there is high promotion potential if more of these roofs are designed to be visible from street level.