At this historical moment, the urban planning and design professions are confronted with the twin challenges of unprecedented rapid urbanization on the one hand, and declining post-industrial regions on the other. In this environment, there are many different and often conflicting ideas about urban heritage and its relevance for contemporary urban planning and design. In this paper, we look for commonalities and a way forward from among a range of competing urban design models. We examine the illustrative case study of the geography and landscape of Detroit, USA. We consider seven contemporary urban planning and design ideals that dominate the contemporary planning and design discourse and their different views of the past and urban heritage in relation to the approaches in Detroit. From these, we draw a synthesis approach, making several recommendations and observations with a focus on the capacities of so-called “placemaking” approaches. In this paper, urban heritage is understood and examined as contributing a pattern of infrastructure that provides a helpful supportive framework, and (importantly) a set of structural limitations (e.g., historic plot boundaries), that can serve as a generative resource for new urban planning and design. We conclude that the necessary framework for democratic participation and opportunity within urban space can be provided most directly by leveraging the assets of urban heritage.

Urban heritage is increasingly expected to contribute to future urban development, not least in declining cities that have experienced drastic economic, social and spatial structural change

Urban landscapes are increasingly understood as dynamic systems in which natural, cultural, and socio-spatial layers continuously overlap and evolve. Within this perspective, heritage and memory are often treated as stable qualities of place, to be preserved or restored amid ongoing urban transformation. This paper challenges that static understanding by advancing memory-in-transformation, a theoretical framework positioned within the broader concept of Temporal Urbanism. Drawing on an integrative synthesis of landscape theory, critical heritage studies, memory studies, and urban theory, the paper argues that urban landscape transformation does not simply affect heritage and memory but actively produces, reconfigures, and redefines them over time. The framework rests on three interrelated dimensions: temporal layering, mediated interpretation, and dialectical production, through which transformation operates as a mediating process linking spatial change, collective memory, and the continuous formation of heritage landscapes. Illustrative cases (Superkilen, Copenhagen; the Slussen redevelopment, Stockholm) show how transformation can destabilize existing heritage while generating new heritage systems. The paper further introduces the notion of temporal justice, foregrounding whose memories are sustained or marginalized in processes of change, and outlines new directions for research and practice in heritage urbanism, land-use planning, landscape architecture, and sustainable urban development.