Contemporary urban planning faces the ongoing challenge of developing Green Infrastructure capable of providing vital ecosystem services. Within this framework, the Barcelona metropolitan area has advanced a network of parks that, while serving local neighborhoods, also aim for metropolitan relevance. This study offers a forward-looking analysis of selected parks in the southern Llobregat River basin—an area shaped by historic villages and working-class settlements—to evaluate their contribution to both Green Infrastructure and the region’s polycentric structure. Building on previous landmark studies and multidisciplinary perspectives, the research examines eight parks through four spatial and scalar lenses, assessing their territorial role and accessibility, ecological connectivity, urban integration and permeability, and landscape design with both qualitative and quantitative data. Using a comparative framework alongside research-by-design methods tested in urban design studios, the research links analytical insights to design-based strategies. The outcome is a set of actionable guidelines aimed at enhancing local park performance, with broader implications for over 50 ‘Metropolitan Parks’ spread in more than 30 municipalities. These insights contribute to shaping a more integrated, livable, and resilient metropolitan region.

Since the 1960s, the suburbanization of Barcelona Metropolitan Region has unfolded under ideals of an “American dream” transplanted into a Southern European context characterized by limited resources and a dispersed network of small urban settlements. This process has produced only a small number of true “garden cities,” alongside a much larger share of scattered single-family housing developments, many of which still suffer from significant infrastructure deficits. This article examines the contradictions and tensions between residents’ expectations and rights, and public policies and regulatory frameworks that have often adopted restrictive rather than constructive approaches. It develops a critical retrospective analysis at two complementary scales in the Barcelona Metropolitan Region. At a large scale, the extent of the urbanization phenomenon is presented through general data, outlining how urban policies over the past three decades have managed to “prevent” new developments of this type. At a more detailed scale, it presents and analyses two contrasting planning experiences co-led by the authors, aimed at upgrading suburban areas located less than 30 minutes from the city center. These case studies include diagnostic assessments, participatory processes, and planning proposals addressing micro-densification, mobility improvements, urban infrastructure upgrading, and the provision of basic services. Finally, the article discusses the need to contain further suburban expansion, including through the reassessment of developable land allocations, while also exploring the consolidation of existing suburban developments by defining urban strategies for their legalization, improving their services, and examining the potential for minimal densification that would enhance the sustainability of these areas.

El artículo presenta el enfoque pedagógico y los resultados de un curso de proyectos centrado en el espacio público y el paisaje, dirigido a estudiantes de quinto año de arquitectura y desarrollado durante el primer semestre del curso 2024-2025 en la Escuela de Arquitectura de Barcelona. El territorio del Maresme, caracterizado por una urbanización fragmentada que coexiste con espacios abiertos de alto valor socioecológico, se utilizó como laboratorio. En este contexto, los proyectos se plantearon como instrumentos capaces de mitigar ciertas disfunciones del tejido urbano, al tiempo que potenciaban los valores ambientales de los suelos no ocupados. El trágico episodio de la DANA que afectó a Valencia actuó como elemento disruptivo, intensificando la conciencia sobre los riesgos asociados a las riadas, también presentes en el Maresme. Este hecho impulsó un enfoque en el que el agua se concibe no como un enemigo a evacuar, sino como un recurso a gestionar, dando lugar a propuestas sensibles al territorio y a sus dinámicas naturales. Entre las estrategias desarrolladas se encuentran el diseño como inicio de procesos ecológicos en evolución, la compatibilidad entre funcionalidad urbana y sistemas naturales activos, y otras reflexiones que se recogen y analizan a lo largo del artículo.