Cities are experiencing an increased rate of climate-related extreme events threats derived from climate change. Floods are one of the most challenging issues to address to reduce damages and losses in urban areas. Building resilience through adaptation to these changing conditions has become a common goal for different disciplines involving planning for the future. Adaptation planning is widely recognized as generally applicable to any field. However, there are current limitations to overcome for architectural and urban planning to switch from theory to practice. This paper proposes a critical overview of literature works on flood mitigative strategies and adaptive approaches considering uncertainties, linking strategies for the Built Environment (BE) to mitigate the effects of floods, and operative frameworks to pursue adaptation under changing environmental conditions. The literature selection accounts for the pivotal components of the BE: open spaces (OSs), buildings, and users. Next, we provide an overview of the most relevant adaptive methodologies that have emerged in literature, and, lastly, the planning strategies are discussed, considering the climate-related uncertainties that might undermine the effectiveness of the designed action. The present paper aimed to provide a contribution to the discussion regarding the necessity of making architectural and urban planning adaptive, providing a base for future studies for operative adaptation.

The complex interaction between city and climate crisis is converting design-based disciplines from deterministic to flexible approaches. In this regard, Decision-Making Under Deep Uncertainty (DMDU) methods and operational strategies can be valuable support mechanisms to cope with the emerging climate fragilities of urban systems. In light of recent advances in the field of adaptive approaches, this paper discusses key concepts, current limitations and the potential to introduce the DMDU in the method and practices of regenerative design. Our critical discussion aims to restore the designer’s role within the DMDU and to reduce current and future climate fragilities in European cities.

Cities are facing numerous challenges such as Urban Heat Island Effect (UHIE) and more frequent flooding events, due to the increasing soil sealing. Greenery and water implemented in urban outdoor spaces have been promoted as effective strategies to counteract UHIE while Sustainable Urban Drainage Systems (SUDS) have been identified as convenient solutions to increase resilience to flooding. However, since many SUDS are green-based, they also benefit urban microclimate and outdoor thermal comfort. In this work, the effectiveness of SUDS as passive strategies to simultaneously improve outdoor thermal comfort and reduce stormwater runoff is assessed. The analysis is carried out on a neighbourhood in Ostia (Rome), selected as representative of Mediterranean climate. The case study area is modelled on ENVI-met in three different scenarios: the current condition is compared with two future developments in which green and water-based mitigation strategies are implemented or in which soil sealing continues based on current trend. Moreover, for each scenario, stormwater runoff has been determined using the Soil Conservation Service curve number method. Results show that the implemented mitigation strategies allow achieving improved thermal comfort conditions and at the same time they can reduce runoff.

Conventional approaches in architecture and urban planning still rest on modernist, deterministic assumptions that downplay the nonlinearity and deep uncertainty that characterize contemporary cities. Sustainability, although crucial, has often been operationalized through incremental, efficiency-oriented checklists that struggle to address systemic transformation. This conceptual theory synthesis reframes the built environment as a complex adaptive system and interrogates three paradigms that have arisen in the wake of the sustainability turn: resilience planning, adaptive planning, and regenerative design. Drawing on an integrative, narrative review of interdisciplinary scholarship, the article maps these paradigms onto a functional “what–how–why” theoretical scaffold: resilience specifies what socio-technical capacities must be safeguarded or allowed to transform; adaptive planning sets out how planners can steer under conditions of deep uncertainty through sign-posted, flexible pathways; and regenerative design articulates why interventions should move beyond mitigation toward net-positive socio-ecological outcomes. This synthesis positions each paradigm along an uncertainty spectrum and identifies their complementary contributions.