Citizens’ perception and willingness to pay for green roofs and nature-based solutions in three Italian metropolitan cities

Nature-Based Solutions have been largely investigated and technically improved in the last decades. Thanks to their multiple benefits, these solutions can largely contribute to the sustainable urban development, especially if diffusely installed over large areas. A key point to support their implementation is to actively involve citizens, increasing interest and willingness to pay for installation and maintenance. Through an anonymous online survey distributed in three Italian metropolitan cities (i.e., Cagliari, Palermo and Torino), this study investigates citizens’ awareness of potential benefits provided by urban Nature-Based Solutions and their willingness to invest in different infrastructures, with a specific focus on green roofs. The aim of the study is to understand how different climatic and socio-demographic conditions could influence citizens’ interest in these tools, also exploring the potential impeding elements perceived by citizens. Results highlighted a higher interest for green roofs on public buildings than on private ones; most of the citizens are willing to financially contribute for green roofs and nature-based solutions in public spaces, with an average of 71€/year. Understanding citizens’ perception of environmental issues and willingness to pay for green solutions is essential for decision makers to properly define investments and incentivization policies, fostering the development of sustainable cities. • Perception of environmental issues demonstrates notable variation across metropolitan cities. • A high level of interest is expressed for the implementation of Green Roofs on public buildings. • Respondents show a clear preference for systems that combine Green Roofs with Solar Panels. • The average willingness to pay for Nature-Based Solutions in public spaces is estimated at 71 €/year.