Global environmental and health issues such as climate change and the COVID-19 pandemic have highlighted the weaknesses of current urban systems, including the poor availability and accessibility of green and public spaces in cities. Nature-based Solutions are configured as promising solutions to increase the resilience and health of the built environment by addressing climate and pandemic issues, promoting the psycho-physical well-being of users and proposing solutions for the protection of the environment and ecosystems. Following a systematic review of the scientific literature using the PRISMA methodology, this study aims to provide a taxonomic framework for Nature-based Solutions for the built environment that is applicable to the urban and building scales, highlighting key benefits in addressing pandemic and climate challenges and achieving urban resilience. This framework proposes a holistic and multifunctional approach that will prove to be a useful tool for researchers and policy makers to incorporate greening strategies into urban regeneration and redevelopment processes. The application of Nature-based Solutions still seems to be limited. It is therefore necessary to raise awareness of this issue among citizens and policy makers and to promote close co-operation between the different actors in territorial decision-making processes.

Urban heat islands (UHIs) increase urban warming and reduce outdoor thermal comfort due to changing surface characteristics and climate change. This study investigates the role of green walls (GWs) in mitigating UHI, improving outdoor thermal comfort, and reducing carbon emissions under current and future (2050) scenarios. Focusing on Via della Consolata, Turin, Italy, the study combines remote sensing for UHI detection and numerical simulations for thermal analysis during seasonal extremes. The results show that GWs slightly reduce air temperatures, with a maximum decrease of 1.6 °C in winter (2050), and have cooling effects on mean radiant temperature (up to 2.27 °C) during peak summer solar radiation. GWs also improve outdoor comfort, reducing the Universal Thermal Climate Index by 0.55 °C in the summer of 2050. The energy analysis shows that summer carbon emission intensity is reduced by 31%, despite winter heating demand increasing emissions by 45%. The study highlights the potential of GWs in urban climate adaptation, particularly in dense urban environments with low sky view factors. Seasonal optimization is crucial to balance cooling and heating energy demand. As cities face rising temperatures and heat waves, the integration of GWs offers a sustainable strategy to improve microclimate, reduce carbon emissions, and mitigate the effects of UHI.

Nature-Based Solutions offer a concrete opportunity to integrate nature into cities and strengthen their resilience, in response to global challenges related to climate change, biodiversity loss, and water management, which are exacerbated by urban expansion and its impacts on the built environment. This study aims to analyze various European policies and urban greening practices, considering not only some European Union member states but also other cities geographically located in Europe. The main goal is to explore how these solutions are used in various European cities to address environmental challenges and improve urban quality of life. The study highlights the growing role of greening strategies in EU urban policies as key tools to tackle global challenges. It finds that green interventions—such as green roofs, façades, and green urban spaces—offer multifunctional benefits, but their effectiveness relies on integrated planning, strong public–private cooperation, and active community involvement. Key challenges include the limited scalability of these solutions in dense or economically constrained areas and the need for long-term financial and institutional support. Overall, the study highlights that greening is not merely aesthetic but central to building regenerative and climate-resilient cities.