Nature-based solutions (NBS) have gained prominence in sustainable urban planning, and among them, green roofs stand out for their ability to improve environmental quality and reduce the carbon footprint of cities. In this context, the study ‘Modelling the potential of Green roof installation for the decarbonization of urban areas. Case study of Valencia, Spain’, prepared by Tomás Pino Gallardo at the Universitat Politècnica de València, presents an innovative methodology to analyse the potential of green roof installation in Valencia through the use of advanced geospatial modelling and computer vision techniques.
The study adopts an integrated approach that combines the analysis of LiDAR data, high-resolution orthophotographs and artificial intelligence tools to identify and evaluate urban surfaces suitable for the implementation of green roofs. A detailed model is generated to accurately map available areas in the city, taking into account structural constraints such as roof slope and accessibility for vegetation installation. This methodology not only identifies viable spaces, but also projects the energy and environmental impacts of their implementation, providing a strategic tool for urban planning decision-making.
One of the most outstanding findings of the study is the identification of 625 hectares of urban roofs with the potential to be transformed into green spaces, representing an intervention on more than 22,500 buildings. The implementation of green roofs at this scale could translate into a reduction of energy consumption of approximately 162 GWh per year, as well as a mitigation of 52,219 tonnes of CO₂ annually, consolidating their role as an effective strategy for urban decarbonisation.
Beyond emission reductions and energy savings, green roofs offer multiple collateral benefits that have a positive impact on the urban environment. One of the most relevant is the reduction of the heat island effect, a phenomenon that intensifies temperatures in densely urbanised areas and affects the quality of life of their inhabitants. The incorporation of vegetation on building roofs helps to regulate temperature, reducing heat absorption and favouring thermal comfort both inside buildings and in the surrounding urban space.
Green roofs also play a crucial role in sustainable water management, as they act as natural filters that retain and purify rainwater, reducing the overloading of urban drainage systems and mitigating the risk of flooding. They also support biodiversity by creating microhabitats for flora and fauna species, promoting the ecological resilience of the city and improving air quality by capturing particulate pollutants and CO₂.
While the potential of green roofs is undeniable, their large-scale implementation faces significant challenges, particularly those related to economic viability and urban regulation. Upfront investment can be a barrier for owners and developers, highlighting the need for fiscal incentives and public-private financing programmes to facilitate their adoption. Policies to support green infrastructure, regulations that integrate sustainability criteria into construction, and public awareness of the long-term benefits of these solutions will be key to overcoming these barriers and fostering their integration into the urban fabric.
This study not only provides an analytical framework for assessing the potential of green roofs in Valencia, but also lays the groundwork for replicating this methodology in other cities seeking effective strategies for decarbonisation and urban sustainability. From the Chair in Urban Energy Transition, we remain committed to the research and implementation of innovative solutions that contribute to a more resilient and efficient city model aligned with the climate challenges of the 21st century.
