The use of Local Urban Plan to limit the effect of heat waves

Heatwaves are meteorological events characterized by prolonged periods of intense heat. They present a growing challenge for societies. Indeed, since 2003 France has faced exceptional heatwaves, with significant implications for public health. These climatic phenomena, exacerbated by global climate change, are generating increased concern at both local and national levels. The presentation will focus on the Freshway project aims to deepen our understanding of the mechanisms, challenges, and strategies inherent in the implementation of cooling solutions at local level. Through a comprehensive analysis, the Freshway project seeks to identify institutional and technological barriers that may hinder the realization of such initiatives. Concurrently, Freshway endeavors to map and detail the adaptation trajectories adopted by communities in response to climate challenges, thereby providing valuable insights for more resilient and sustainable urbanization. The project included several study sites, including Paris, Montreuil, Pontault-Combault, and Sarcelles in the Ile-de-France region, as well as Montpellier, Castelnau-le-Lez, and Beziers in the Occitanie region. Among the different results of the project, this paper focuses on the use of local planning document to limit the effect of heat waves. Methods: This study presents a multidimensional approach to understanding urban trajectory for planning and acting against heat waves. Through in-depth individual interviews with key stakeholders from local authorities, valuable insights were gathered on the challenges and issues encountered in urban planning and management. Concurrently, a detailed description of emblematic achievements provides a tangible overview of innovative land-use practices in response to heatwaves. Moreover, our research incorporates a rigorous analysis of geographical data, examining trends and transformations across various temporal scales, including the evolution of urban minerality versus the evolution of urban vegetation. Special attention is devoted to a detailed examination of the PLU (Local Urban Plan, the French land use regulation document), offering an in-depth perspective on the strategic and regulatory directions shaping urban development. Findings: Montreuil, located in the inner suburbs of Paris, demonstrates a strong political commitment to urban cooling initiatives, while simultaneously facing intense land pressure due to high urban densification, in alignment with regional objectives. Recent modifications to the PLU have strengthened regulatory constraints, notably through the full-ground coefficient (CPT), construction coefficients (CES), and the establishment of protected landscaped areas (EPP). Since 2020, the number of EPPs has significantly increased, rising from 51 to 163, with particular attention given to targeted smaller spaces, sometimes of a private nature. This evolution reflects a proactive approach aimed at reconciling urban development with environmental preservation. Conclusion: The Freshway project focuses on understanding and implementing cooling solutions in response to climate challenges, analyzing community adaptation trajectories. Utilizing interviews, documents analysis and geographical data, the study investigates urban dynamics, such as in Montreuil, where a strong political commitment to urban cooling coexists with challenges related to densification and local regulations. Funding: Freshway Project, 2022-2025 , funded by ADEME PACT program