CoHabiter

CoHabiter: Residential Scenarios for Biodiversity and Residents

Scientific supervisor: Emmanuelle BAUDRY

Host institution: Université Paris-Saclay

Context

Residential green spaces (RGS) – that is, the private gardens of single-family homes and the shared green areas of multi-family buildings – constitute a major, yet still understudied, component of urban ecosystems. These spaces serve a dual and important function: as the predominant green spaces within cities, they provide refuges and essential ecological corridors for urban biodiversity, while also delivering significant social benefits (as important sources of well-being, food production, and social interaction).

Despite their ecological and social value, these RGS – due to their great structural, governance, and usage heterogeneity, as well as their inaccessibility – remain largely overlooked in both urban planning and scientific research. Furthermore, in the current context of intense pressure to build housing in French cities, RGS are often viewed as land reserves. So-called “soft” densification – which involves adding one or more housing units to an already built-up lot- is thus a solution currently promoted in France through various legislative and legal measures. However, this leads to a reduction or loss of the multifunctionality of RGS, often without an adequate assessment of the trade-offs involved.

The project

The CoHabiter project aims to address this gap by adopting an interdisciplinary approach at the intersection of ecology, urban planning, geography, and the sociology of law, structured around three main areas of focus.

  1. The first research focus will assess the ecological and social functions of RGS across four distinct study areas. Biodiversity surveys will be conducted in these areas, along with interviews with residents regarding their uses, perceptions, and perceived benefits related to these EVRs, as well as interviews with local authorities and urban planning professionals regarding public policy tools. A diachronic analysis will characterize past patterns of densification.
  2. The second focus will generalize these findings to the national level by combining high-resolution spatial data with data from citizen science. At the same time, a national quantitative survey will measure the benefits perceived by residents based on these same parameters.
  3. The third focus area will draw on all of these findings to develop and evaluate densification scenarios, with the aim of identifying optimal development strategies for RGS that balance environmental performance with residents’ quality of life. The CoHabiter project will produce actionable knowledge and decision-making tools for urban stakeholders in the context of urban densification.