Niklas Gerst – Greening urban planning in practice. A Franco-German comparison of practices for implementing local urban planning documents (PLU, BLP)

Urban planning has undergone significant changes in Europe in recent years. In France in particular, these have resulted in a strengthening of town planning documents, making them a key focus of local public policy. The Local Urban Development Plan (PLU), often inter-municipal (PLUi), serves as the reference document for the granting of planning permissions (building, development or demolition permits, and prior declarations), and therefore for the majority of projects carried out in towns and cities. Whilst the ‘Zero Net Land Take’ (ZAN) objective, aimed at reducing land consumption, represents one of the major shifts in planning and thus in the evolution of urban development in response to climate challenges, it is not the only one. Indeed, town planning documents are increasingly incorporating provisions aimed at mitigating climate change, adapting to its effects and limiting the loss of biodiversity (Chavez Colmenares 2024). This development is part of a broader trend towards the ‘greening’ of urban planning. At the same time, the changing role of the PLU(i) reflects the logic of ‘project-based urban planning’ (Demouveaux and Lebreton 2017), which involves, in particular, defining a territorial development strategy, but also evolving the relationship with private sector stakeholders, who are essential links in territorial policies. In the face of reduced resources for public bodies and rising land and property costs, the urban planning document serves as a tool to steer these bodies’ projects towards the objectives set by local authorities, thereby enabling public action at a lower cost. However, more environmentally friendly urban planning comes up against deeply ingrained, even routine, perceptions and practices regarding the creation of space. Indeed, much research highlights the complexity involved in changing the practices that greening entails. They highlight the challenge posed to stakeholder networks, standards, economic models and, more generally, established ways of working, for which the integration of ecological considerations leads to difficulties or even conflicts. These can hinder the implementation of certain projects by stakeholders with limited resources or those seeking to maximise the economic profitability of their operations. Building on these observations, this thesis aims to understand how the various stakeholders involved with the regulations set out in town planning documents (various local authority departments, elected representatives, private individuals, property developers and designers) incorporate these regulations into their work, the ways in which they impact projects, and how these regulations serve as a basis for dialogue and negotiation between the stakeholders, particularly with regard to the granting of planning permission. In particular, the aim is to analyse how the regulations actually influence project design, but also to understand their (non-)application in light of the numerous objectives set out in the texts, which can sometimes be contradictory. To this end, a comparative analysis of the practices involved in implementing town planning regulations in France and Germany should provide a better understanding of how these regulations are embedded within project dynamics and the interplay of stakeholders against a backdrop of global transformation. Whilst both countries have a strong planning culture, these are not identical, particularly due to their different institutional and administrative systems. This research will provide a better understanding of the practical role of regulatory urban planning in both countries, whilst also offering an operational perspective on the study of planning in Europe and its concrete effects.