This thesis examines the roll-out of anaerobic digestion in the Île-de-France region to shed light on the issues at stake in the schemes being developed in the name of the ‘green city’. Also known as ‘anaerobic digestion’, this process of breaking down organic matter in the absence of air produces a gaseous mixture and digestate, a kind of humus. Its multifunctional nature (waste management, energy production, compost production), its significant flexibility (in terms of technical intensity, inputs and uses) and, above all, the dual environmental promise (as a method of producing so-called renewable energy or as a tool for the circular economy) with which anaerobic digestion can be associated make it a preferred technique for those interested in environmental issues in the broadest sense.

By analysing diverse processes of framing, mobilisation and engagement in the Île-de-France region, as well as the trajectory of different types of arrangements, the thesis demonstrates the primacy of those visions and mechanisms most compatible with the energy system, particularly those associated with major gas networks. It also demonstrates that the interplay between waste management and energy production is not self-evident and is subject to tensions. Beyond these two issues, the thesis highlights the multiple ‘spillover effects’ of the development of anaerobic digestion in environmental terms (water and soil quality, etc.) and socio-economic terms (associated agricultural model).

The issue of the energy transition is now at the top of the political agenda. The aim of this thesis is to examine the emergence of a new electricity model, to identify its characteristics, and to determine whether it represents an alternative to the centralised model.

By combining three analytical perspectives – institutional, technological and territorial – she demonstrates that this centralised model has had its day. A series of changes has profoundly transformed the electricity system in terms of both its physical structure and its organisation: liberalisation, distributed generation, political decentralisation, etc. The new configuration that is emerging is hybrid. It is the result of tensions between, on the one hand, innovations bringing about significant socio-technical changes and, on the other, mechanisms of political-administrative centralisation and technical-economic concentration. The state has lost its hegemony but not its centrality, even as the sector has diversified (in terms of players and technologies) and electricity has become widespread throughout society (access to generation, legislative processes, etc.). Neither the EU’s thwarted rise in competence, nor liberalisation, nor the emergence of local authorities have completely undermined its ability to position itself at the centre of the sector’s regulation. Its approach is at once selective (withdrawal from day-to-day operations), inclusive (renewable energy, local authorities), diffuse (funding, R&D, legislation, etc.) and, at times, interventionist (shareholding, pricing, transmission and distribution networks, etc.).

In a liberal context, the State adapts through pragmatic reform of its activities and the controlled integration of alternative approaches. This ‘tamed liberalism’ corresponds to a decentralisation of public energy policy, within which local authorities are asserting themselves through a process that is both bottom-up and top-down. These local authorities are, on the one hand, primarily through the EPCIs and regional councils, establishing themselves as essential partners of the state in the implementation and management of a variety of sub-national processes and technical mechanisms.

On the other hand, they wish to assert themselves in this sector and have operational levers at their disposal to do so (concessions, planning, support for renewable energy, information, etc.). This process of taking ownership remains partial and uneven today, but represents a strong trend that is making the local level the new frontier for the sector, including for the State, which is adapting its administrative organisation to the regional level. A process of local authority empowerment, of a legal nature, is therefore underway, organised by the State and falling under the remit of autonomous energy management, which cannot be reduced to the development of energy production capacity. The new boundaries resulting from this empowerment lead to an arrangement of institutional territories that do not fundamentally call into question the national level or the role of the State. This hybrid configuration depends on the terms of production development, which are subject to technical and economic concentration mechanisms specific to the electricity grid industry, its context, and spatial and territorial logics dependent on infrastructural parameters. This is demonstrated by the counter-intuitive deployment of distributed generation, which takes the form of a hybrid centralised/decentralised model, resulting from the interaction between forms of control and specific socio-technical conditions (spatialisation, logics of scale, concentration of actors, etc.). The emerging configuration combines elements of disruption/decentralisation and continuity/centralisation. Given the significance of future developments – ICT, storage – this likely represents only one stage in a long journey towards a new energy model.

Members of the jury

• Sabine Barles (University of Paris I)
• Olivier Coutard (LATTS, PhD supervisor)
• Gilles Debizet (University of Grenoble Alpes)
• Jérôme Dubois (Aix-Marseille University)
• Alberto Pasanisi (EIFER)
• François-Mathieu Poupeau (LATTS).

Urbanisation in Tunisia has continued to grow at a rapid pace, resulting in territorial imbalances and the establishment of a planning system whose limitations have been the subject of several studies. It is against this backdrop that, over the past two decades, strategic planning has begun to be introduced into urban policy in Tunisia under the banner of the ‘City Development Strategy’ (CDS). The aim is to define a vision for the city, broken down into strategic objectives, the implementation of which will be ensured through concrete actions. The development of these SDVs involves various stakeholders (public sector actors, civil society, experts, etc.) and takes an integrated approach to different dimensions (spatial, economic, social, etc.).
Drawing on the cases of Tunis, Sfax, Sousse and Jendouba—two of which were developed before the Tunisian Spring and the other two after—this thesis aims to test hypotheses treating these SDVs as reflections of changes in governance.
We examined the four strategic planning processes in Tunis, Sfax, Sousse and Jendouba through five lines of inquiry: the international dimension of the SDVs, their development methods, the study of representations, organisational structures and, finally, practices.
This work has led us to three main findings. Firstly, our analyses led us to conclude that the four processes studied reveal continuities with certain approaches to urban planning that already exist in Tunisia, thereby putting the impact of the ‘Tunisian Spring’ on urban planning practices into perspective. Secondly, our analyses also led us to conclude that the four case studies reflect transformations that have concerned only specific aspects of urban planning and apply to very specific fields. Finally, the third finding of our research showed that the four case studies (including those conceived before the ‘Tunisian Spring’) brought about a renewal of urban planning in Tunisia and were the catalyst for changes at several levels of urban governance.

Abandoned luggage has long been a problem in the transport sector and in the management models of complex socio-systems such as metropolitan railway stations. The issue is attracting increasing attention from both managers and institutions, as the number of so-called ‘abandoned’ items (those not claimed or returned to their owners within 20 minutes) rose by more than 50% between 2020 and 2022, prompting the SNCF to devise two complementary strategies:

– On the one hand, a focus on providing enhanced support for passengers, through staff and digital tools (station announcements, text message campaigns, CCTV, and luggage tracking via QR codes or geolocation). This approach is part of the station manager’s commitment to implementing ‘benevolent surveillance’, encouraging individual behaviour based on vigilance and interactions that help prevent potentially disruptive behaviour;

– Furthermore, to resolve cases of unclaimed luggage, the implementation of a regulatory protocol (January 2020) that is both very strict and highly disruptive to business continuity (with the security perimeter extended to 200 metres and the evacuation of railway land). Abandoned items can be seen as ‘grains of sand’ that hinder the railway system and, in a systemic way, undermine all other ancillary activities within railway complexes.

This dual response, which is both preventive and remedial, involves decision-making and experimentation in the technological, organisational and institutional spheres, as well as in the realm of the relationship between the company and its customers. The thesis therefore examines the continuum of practices and responsibilities that are assembled and negotiated around these neglected areas within the fields of reception and information, flow management, security and commercial services.

This thesis lies at the intersection of the field of socio-technical analysis of risks and crises (LATTS) and the field of logistics and digital mobility services in railway stations (LVMT). It forms part of the ‘material turn’ in the social sciences and examines the object in terms of the practices, relationships and spatialities it engages in with a subject, and more broadly, with networked actors. The empirical work will therefore reveal the as yet barely visible links between, on the one hand, surveillance—often regarded as overarching and panoptic—and, on the other, a benevolent, partnership-based relationship mediated by humans and machines. It will juxtapose, if not contrast, the organisational and institutional transformation brought about by the process of transcribing and translating security protocols within the highly constrained frameworks of station management, amidst the clash of sometimes rival professional cultures and identities. The aim of the thesis is indeed to show what the neglected object teaches us about the interplay of the processes of digitalisation, security and value creation at work in transport hubs, against a backdrop of profound institutional reforms (opening up to competition) and rising risks and uncertainties.

Many urban properties and spaces in major cities are becoming financial assets. Offices, shopping centres, student accommodation and large-scale facilities are being acquired by investment funds and listed companies that capitalise on the future revenue streams generated by the use of these buildings by businesses and residents. Urban regeneration through the development of mixed-use neighbourhoods is, via the financing channels of the property markets, linked to the financial markets. This thesis aims to analyse this financialisation of urban capitalism by examining the interplay between urban government policies and the financial strategies of property asset managers. The power relations between these two actors and their socio-spatial and material effects are examined through a comparison of two major development projects located in Greater Paris and Greater Lyon. It is from this perspective that the study focuses not only on the operational projects themselves, but also on the property fairs where they are presented, and on metropolitan strategies.

Research shows that, despite differing political orientations, the construction of standardised, polarised commercial property reserved for a handful of large companies shapes urban regeneration in both cases. These conditions align with the selective investment criteria of asset managers, which property consultants and developers convey to local authorities. They result from processes whose contentiousness varies according to local agendas. Following intense negotiations led by developers, the municipality of Saint-Ouen abandoned certain key principles of the Docks project. The development of the Carré de Soie, by contrast, resulted in a consensus between developers and Greater Lyon regarding the creation of a commercial hub. Two local configurations are put forward to interpret this comparative outcome, which is conducive to financialisation. The lack of regulation of office development at the level of the Paris metropolitan area leads to localised negotiations within the project, where municipal objectives are constrained by the prioritisation of political agendas, the financing arrangements for the development, and the nature of the land. In the Lyon metropolitan area, the institutionalisation of a property supply policy driven by the executive and the economic development departments of Greater Lyon organises the circulation of investment standards across the conurbation and reinforces their influence on urban planning.

Building on these findings, the thesis proposes an urban political economy interpretation of the financialisation of the urban environment as an alternative to Marxian theory, emphasising the role of asset managers and highlighting their mediating role. It contributes to theories of urban power by demonstrating the limited influence of local agendas on the selective effects of financialisation, and by discussing the formation, under certain conditions, of a financialised growth coalition.

Members of the jury

• Philip Ashton, Associate Professor, University of Illinois at Chicago (Rapporteur)
• Ève Chiapello, Director of Studies, EHESS (CEMS)
• Sylvie Fol, University Professor, University of Paris 1 Panthéon-Sorbonne
• Ludovic Halbert, CNRS Research Fellow (LATTS) (Co-supervisor)
• Christian Lefèvre, University Professor, Université Paris-Est (Supervisor)
• Gilles Pinson, Professor, Sciences Po Bordeaux (Rapporteur)

This research focuses on defining a post-war British urban planning tradition and its transmission to France in the context of the construction of new towns. The first part of my thesis seeks to outline the contours of this tradition. I use the term ‘tradition’ to refer to a coherent body of know-how, methods and operational concepts, commonly used by a group of professionals and partially codified. The period under consideration spans some thirty years, from around 1940 to 1970.

The key players belong primarily to two major public institutions, acting as both project owners, planners and builders: the London County Council’s Department of Architecture, responsible, in particular, for drawing up the 1943 London Plan and its implementation in the British context; and the IAURP, responsible for the creation of new towns in the Paris region in the French context. I analyse the urban planning practices of officials from these two institutions, their use of urban concepts, the planning mechanisms and methodological approaches they implement.

The thesis is structured in two parts: the first defines these urban planning concepts within the British context and examines how they were put into practice and formalised; the second analyses their reception and adaptation within the French context, as well as the motivations of the key players involved.

The aim of this thesis is to examine the processes of densification in predominantly detached-house neighbourhoods within suburban and peri-urban areas, which have so far received little attention in terms of their morphological transformations. To this end, we adopt an approach rooted in the political economy of urban production, which seeks to examine jointly the political, economic and social aspects, as well as the regulatory and technical factors, that may explain the material reality of the urban transformations observed. In this regard, we bring together two strands of research: work on territorial political economy and work on the economics of spatial planning. More specifically, the concept of post-suburbanisation—understood as a widespread process of intensive development that affects suburban areas in different ways and leads to the gradual autonomy of these suburbs from the central city of the conurbation—is at the heart of our approach.

Post-suburbanisation differs from suburbanisation, which was based primarily on extensive urban development. It therefore raises the question of densifying the low-density residential areas inherited from the suburban era. However, not all local authorities are seeking to densify; some deliberately prevent densification, whilst others, on the contrary, seek to encourage it. This leads us to formulate the central hypothesis of our work, namely that there is a link between a local authority’s post-suburban strategy and the preferred form of densification.
We have studied densification processes in predominantly detached-house neighbourhoods, in contexts characterised, amongst other things, by the existence of explicit local densification policies, in two municipalities in the Toronto metropolitan area in Canada (Guelph and Markham) and in two municipalities in the Paris region in France (Magny-les-Hameaux and Noisy-le-Grand). A comparison of the four case studies reveals two main types of densification processes: soft densification processes (Guelph and Magny-les-Hameaux), characterised by densification without a change in urban form; and strong densification processes (Markham and Noisy-le-Grand), characterised by a significant alteration of the urban form that may lead to the replacement of all or part of the pre-existing detached housing stock with apartment blocks. This is our first finding.

A detailed analysis of contextual processes and the various policies specifically aimed at densification reveals a second finding: in all four municipalities, the stated densification policies are explicitly linked to a pursuit of relative centrality. The form of densification observed within predominantly suburban areas thus appears both as a means and as a result of the degree of centrality sought by a given municipality within the post-suburban hierarchy. More specifically, in the cases studied, incentive-based policies for gentle densification are implemented in municipalities adopting a strategy of centrality with a largely local scope, which translates into a policy of moderate, mainly residential growth. Whereas strong densification policies (whether incentive-based or interventionist) are the preserve of municipalities adopting a sub-regional centrality strategy, which translates into entrepreneurial-style policies aimed at attracting households and jobs to their territory. This research also shows that whilst densification processes result mainly from market mechanisms that manifest themselves differently depending on the national urban and cultural context, the policies implemented play an important role in the creation of these land and property markets.

Finally, we identify four types of local policies aimed at increasing the density of predominantly suburban areas: incentive-based policies for gentle densification, incentive-based policies for intensive densification, interventionist policies for intensive densification, and interventionist policies for gentle densification. These different types of policies influence, in distinct ways, the form (resulting urban forms) and configuration (stakeholders involved, stakeholders affected, distribution of capital gains) of densification processes.

Coworking spaces are workspaces shared by individuals from various
organisations within an open-plan environment. This thesis analyses the development of the coworking
market in the Île-de-France region in relation to the ways in which work is carried out in these spaces. The role of physical proximity in the development of collaborative practices is examined in a Parisian coworking space. The study of the intersections between commercial and non-commercial exchanges demonstrates that reciprocal effects help to strengthen the bonds between coworkers.

Coworking spaces can facilitate entrepreneurial projects through peer learning and access to shared resources within the space. However, this requires coworking managers to organise collaboration and make it visible. They transform coworking into a new form of property service that combines physical space with an informal service for connecting workers. The value of coworking spaces is therefore co-created by the users.

This thesis also examines the development of coworking in the Île-de-France region in the context of a range of public policies. Local authorities helped to shape the market before property developers brought about a shift in scale within the very concept of coworking. The coworking operator has become an intermediary enabling the pooling of office demand from small businesses in metropolitan areas, and has come to occupy a place within the property value chain.

Members of the jury

• Didier Paris, Professor, University of Lille 1
• Antoine Picon, Research Director at École des Ponts ParisTech (PhD supervisor)
• Raphael Suire, Professor, University of Nantes (Rapporteur)
• Pierre Veltz, Professor Emeritus at École des Ponts ParisTech
• Elsa Vivant, Senior Lecturer, Université Paris-Est (Joint thesis supervisor)
• Sharon Zukin, Professor, Brooklyn College, City University of New York (Rapporteur)
• David Cocheton, Director of Planning, SEM Plaine Commune Développement (Guest)

This thesis aims to re-examine the concept of reconstruction following the Fukushima nuclear disaster in March 2011. By examining the reconstruction policy launched by the Japanese authorities in the wake of this disaster—despite the health risks posed by low levels of radiation persisting in the environment—it explores the socio-cultural consequences of this policy on those affected, whether they leave, remain or return to the contaminated areas. What form should reconstruction take following this nuclear disaster? What form should reconstruction take in contaminated areas, for populations affected by this disaster and facing this long-term health and environmental risk?

To address these questions, this thesis first analyses the Fukushima disaster in three phases – before, during and after the event – and the management of this disaster at two levels – collective and individual. It also examines the socio-technical controversies surrounding the risk posed by low doses of radiation – a risk that extends over a wide area and a long period of time – thereby enabling us to grasp the complexity of this ‘post-accident’ situation in a nuclearised Japanese society.

Secondly, this thesis conducts a comparative study of the Minamata disaster, caused by mercury contamination dating back to the 1930s. By analysing these two case studies in their various dimensions – uncertainty, risk and the onset of the disaster – it highlights the process of reconstruction, or even rebirth, of a Japanese society repeatedly affected by techno-industrial disasters, a mirror image of the country’s development and modernisation.

Members of the jury

• Claudine Burton-Jeangros, Professor, University of Geneva (Rapporteur)
• Sophie Houdart, Research Director, CNRS LESC (Rapporteur)
• Paul Jobin, Associate Research Fellow, Academia Sinica (PhD supervisor)
• Valérie November, Research Director, CNRS (PhD supervisor)
• Philippe Pelletier, Professor, University of Lyon 2 (Examiner)
• Sandrine Revet, Research Director, CERI, Sciences Po (Examiner)
• Sezin Topçu, Research Fellow, CNRS CEMS-EHESS (Examiner)

How do different state structures and urban and energy socio-material contexts explain the uneven
diffusion of district energy systems (DES) in urban areas of France and Alberta between 2000 and 2014?

To answer this question, this thesis analyses the processes inherent to low-carbon energy transitions
through socio-spatial and socio-material lenses, considering power relations and state structure. At the
intersection of urban planning and energy systems, DES proves practical to explore the nexus between
low-carbon governance, energy governance, and urban governance.

Theoretical frameworks employed in the analysis include :
1) recent contributions from (urban) transition studies and socio-technical systems;
2) a Lefebvrian conceptualisation of socio-space and social changes;
3) Jessop’s (1990, 2008) strategicrelational approach of state power.

An original inter-scale comparative research allows for examining the uneven construction of low-carbon energy policies in France and Alberta, and their relations with state structures, and existing urban and energy systems. Jessop et al.’s Territory-Place-Scale-Network (TPSN) framework is mobilised to overcome the issues of commensurability and spontaneous comparison.

This theoretical and methodological approaches provide a robust demonstration that the provincial scale in Canada, and the national scale in France, are the scales dominating the construction of low-carbon energy transitions and urban governance. Despite similar state powers, French and Albertan governments
developed different state policies on low-carbon transition, highlighting selectivity in the exercise of state
capacities.

They differently engaged and enabled local urban governments and developed different state
interventions on DES. In France, state-sponsored DES activated new channels of growth compatible with
existing dominant socio-materialities; in Alberta, state-funded DES experiments failed to activate new
channels of growth compatible with dominant socio-materialities. This thesis posits that selective
construction of low-carbon policies depends on the material interests of dominant energy and state actors.

In other words, the state does not seek to reduce greenhouse gas emissions by all means. Rather, it seeks
to reproduce dominant socio-material status quo, adapting low-carbon policies to existing socio-material
configuration. Ultimately, this thesis validates how the concepts of state structure and the TPSN framework can enrich the theorisation of space and power relations for (urban) transition studies.

Members of the Examination Committee

• Julia Affolderbach, Senior Lecturer, University of Hull, United Kingdom, Examiner
• Sophie Van Neste, Professor, Institut national de la recherche scientifique (INRS), Montreal, Canada, Examiner
• Olivier Coutard, CNRS Research Director, LATTS, Université Paris-Est, Co-supervisor
• Noel Keough, Professor, University of Calgary, examiner
• Byron Miller, Professor, University of Calgary, Canada, co-supervisor
• Jonathan Rutherford, Research Fellow (ENPC), LATTS, Université Paris-Est, examiner.