Societal interest and willingness to pay for green roofs in Sardinia

Among the different nature-based solutions proposed for the sustainable development of urban areas, green roofs are becoming more and more popular, thanks to their multiple benefits. Indeed, these nature-based solutions reduce the pluvial flood risk during rainfall events, contribute to the thermal insulation of buildings, mitigate the urban heat island effect, and improve the air quality. The knowledge that citizens have about green roofs, the interest and willingness to pay for their installation are still poorly investigated and quantified, although this meta-information could be a valid support and guidance for policy makers and urban planners. In this work, we investigated, through an anonymous online survey, the perception of people living in Sardinia on the most common urban environmental issues (i.e., urban flood, increase of temperature, energy consumption, air pollution and lack of green spaces), and the willingness to pay for green roof installation on both public and private roofs. We estimated the empirical relation among environmental issues awareness and the willingness to pay for a specific green solution while trying to relate the latter to socio demographic characteristics. Results show that citizens are very interested in having green roofs on public building, and on average they are willing to pay around 35 euro per year for their installation and maintenance. The interest for green roofs on private building is, on the other hand, lower than on public ones, due to the high installation and maintenance costs. Moreover, when possible, citizens would rather have solar panels instead of green roofs, since they fully perceive the economic advantages deriving from the installation and are not fully aware of the green roof benefits.