The recent theory of planning and urban design highlights how healthy vibrant cities behave as complex adaptive systems that are subject to spontaneous cycles of regeneration and decline. Although such systems cannot be designed entirely top-down or controlled, they can be influenced. In this perspective, the present paper investigates the power of spatial design to intervene in site-specific adaptive cycles, in order to foster processes of spontaneous self-regeneration and prevent or invert emergent decline. Such a systemic approach to spatial design endeavours to frame the most appropriate type, position and scale of minimum interventions which can maintain the system between the extremes of uniformity and diversity, stability and dynamism, thus preserving its adaptive capacity. The two case studies presented here show how such an approach succeeds in
(1) increasing the system’s ability to keep self-organizing in new better social-spatial configurations (which can neither be predicted, nor predetermined),
(2) triggering cross-scale incremental positive effects which extend in time far beyond the scale of the project site, and
(3) minimizing social and economic costs, an aspect which is particularly relevant at a time when economic resources are extremely limited.
Keywords: spatial design, complex adaptive systems, urban regeneration, self-organization, multi-scale thinking