The implementation of greenery in intermediate spaces at the domestic, community, and urban scale in Barcelona

Since the early 21st century, the city of Barcelona has promoted the integration of vegetation into its urban fabric as a response to increasing density and the progressive loss of greenery in the built environment, both of which have negatively impacted environmental quality. In this context, intermediate spaces—zones of transition between interior and exterior—emerge as a concrete opportunity to articulate environmental, social, and sensory functions. Traditionally, nature has been associated with open spaces and housing with interior shelter; the intermediate space acts as a meeting point between these two worlds, allowing for a more balanced relationship between architecture, the natural environment, and human habitation.
This research is developed through a multiscalar and comparative approach, structured as a compendium of three published scientific articles. Each article addresses a case study that exemplifies a specific scale of intervention. The first examines the domestic scale through the analysis of Casa Figini in Milan; the second focuses on the community scale by studying rooftop extension projects by La Casa por el Tejado in Barcelona’s Eixample district; and the third explores the urban scale through the cases of the Turó de la Peira sports facility courtyard and the Sants Gardens. These three cases form the analytical core of the thesis and allow for a comparative understanding of strategies for integrating greenery in different architectural contexts.
The study identifies a set of common characteristics of naturalized intermediate spaces based on the analysis of selected works of modern architecture from the twentieth century, both outside and within Barcelona, as well as in recent interventions carried out in the Eixample district. These characteristics are validated transversally through their comparative application to the three case studies, demonstrating that the incorporation of greenery at different scales significantly contributes to improving climatic comfort, sensory well-being, and the environmental quality of the built environment.
Finally, the research proposes future lines of investigation aimed at reinforcing the role of green intermediate spaces as strategic infrastructures essential for the development of more sustainable, resilient, and human-centered cities.