Les formes de la métropole : du réseau à la canopée, de la mesure au paysage - TEL - Thèses en ligne Accéder directement au contenu
Hdr Année : 2016

Urban forms: from networks to canopies and from measures to landscapes

Les formes de la métropole : du réseau à la canopée, de la mesure au paysage

Manuel Appert

Résumé

With the SKYLINE (ANR) research programme, I led a group of researchers in exploring the landscape issues at stake in connection with towers, focusing attention on a particular dimension of the city landscape: the skyline. Because of their architectural characteristics and their prominence, towers become part of the material landscape at all levels. On the other hand, only they can be read and have an impact on the wider landscape in its volume. Sometimes, they act as symbols of a dynamic economy and/or urban renewal and translate into a political project (McNeill 2005; Appert 2008, 2011, 2012). As they are highly visible from far and near, they are among the most widely contested buildings at a time when the landscape is being remobilised both as a living environment, and to win over local populations when it comes to urban projects. In European cities, opposition to towers has become more organised and more widespread: London (Appert and Drozdz 2010), Paris (d’Aboville 2015), but also Seville, Vienna, Barcelona, Geneva and even Saint-Petersburg are affected (Dixon 2009). The first part of Volume 3 describes the resurgence of towers in Europe and elucidates the motivations behind this. The post-war boom years and adherence to urban and architectural modernism precipitated the first construction phase of skyscrapers, both in Eastern and Western Europe. Verticalization of the cities of the continent was brought about by the combined effect of real estate developers and large-scale planning projects by public authorities. The repeated economic crises in the 1970s and 1980s and the rise of heritage preservation aspirations diminished the desire for towers, which were rejected both by a sector of the population and city councils. The 1980’s and 1990’s saw an all-time low, with just a few exceptions. After this “fallow” period during which very few towers were built, European cities saw a renewed enthusiasm for this architectural and urban form. While the resurgence of skyscrapers has, to date, been somewhat timid in France, it has reached unprecedented proportions in a significant number of other European countries, reflecting a complete change in economic and political contexts. The need to densify cities to meet the demands of sustainable development has broad political consensus. This need is met by a public-private partnership in which city councils become entrepreneurial and adopt an agenda of growth, which usually takes the form of policies that aim to make urban districts more attractive. In this context, towers are once again justified. They are synonymous with maximising land use for residential and commercial functions and – when they are located close to public transport hubs – with signs of network centrality and urban renewal. Economic logic will prevail in what is offered; the choice of towers does not emanate from the people and not necessarily from city councils either. Real estate promoters are henceforth the key players in verticalization. Elected representatives, such as Gérard Colomb in Lyon, or indeed Ken Livingstone and Boris Johnson in London, won over by the symbolism of the towers, mastermind projects to promote their areas. Negotiated urbanism, particularly in the case of London, aims first to accommodate urban growth to the detriment of heritage protection or housing supply. The image of towers will often remain complex and polarised. French players questioned for this part of the study confirmed the hypothesis of the shock factor of modernist architecture of large housing developments among professionals, elected representatives and a section of the population. Taking cognizance of this negative mindset, promoters are not reckoning on a “spontaneous” resurgence of towers (Fincher, 2007; Mollé, 2016). Rather they are tending towards remobilising the mindsets of elevation, domination and distinction to reformulate their vertical housing and office offers as commercial products that combine accommodation, views and lifestyles. The second part of volume 3 revisits the landscape issues at stakes with the return of towers in Europe. Scientific research that has sustainability in its sights, had for a long time failed to recognise the impact the towers had on the landscape. Promoting a sustainable city should not be limited to identifying and creating conditions for lower energy consumption. We should also consider the potential change in the relationship between urban societies and their landscape in the context of verticalization. Projecting urban activities, standards and regulations, the urban landscape is also a territorial marker, a sign of living together and a social and economic resource. The return of towers is mobilising several landscape dimensions. In most cases the skyline - even if it is not always named - is at the core of conflicts between economic players, professionals, elected representatives and associations in terms of material existence and representation of a large part of the urban area read vertically. The second part of the Volume is devoted to this idea. Having recorded and analysed the conflicts in relation to the skyline (Appert, 2008, 2011; Appert and Montès, 2015), I now propose to decrypt the skyline, to stabilise its content and contours, and to discuss its physical and mental representations in order to feed the public debate. The reflection is also intended for a host of players, city councils and associations who are confronted with increasing pressure in favour of verticalization. The proposal I have devised to define the skyline is based on three assumptions. First, the skyline covers a material dimension: it corresponds with an entire combination of views and viewpoints which lead the eye to observe large portions of the urban territory engaging its verticality against the sky. Then, the skyline has a social and cultural dimension: it projects human activities, cultural, social and regulatory norms. In return, through the representation of players, it carries economic values and contributes to lifestyle and well-being. Finally, the skyline is political: as projector and landmark of a pluralist urban society, it is the subject of debates and regulations. The term skyline thus becomes a scientific object that the geographer may engage with, both in a heuristic perspective and in the purpose of decision-making (Chapter 3). Defining the skyline constitutes a first phase in which to discuss three dimensions of the notion, with as many different methodological approaches: the material presence of the vistas and visibility, especially through modelling (Chapter 4), the significance and aesthetic aspects of the skyline, mobilising more sensitive and cultural approaches (Chapter 5) and their reception by experts and lay people gathered by means of surveys (Chapter 6). The last part of Volume 3 constitutes a programme of future research to be carried out in an extension of the ANR SKYLINE programme. This future research will deal with the vertical city, which I continue to feed through two distinct lines of research: dwelling practices in the towers, and the definition and assessment of the urban canopy. The first line, one of the 4 of the industrial chair HEVD (Université de Lyon, labex IMU) is examining dwelling practice in the towers through the production of a vertical home, its representations and the lifestyles therein in France and the United Kingdom. The first observation is the exclusion of the choice of towers in urban renewal schemes in France, even though the other European countries have cumulatively approved more than 350 projects (Appert, 2015). After characterisation of the projects approved in the United Kingdom, it will be a question of examining the exclusion of this architectural choice in France through the recension and analysis of the strategies employed by the players in the real estate industry, as well as the representations with respect to residential towers in France, whether by professionals, players in the real estate industry or people living in towers. Then I will do a more specific study on lifestyles and habits (domestic, mobility, sociability and use of spaces) in private and social housing in residential towers using several case studies. Finally, I will analyse the regulatory constraints and the technical and economical contexts associated with the construction of vertical accommodation in order to understand their repercussions for, on the one hand, the strategies of the players in the real estate industry and on the other, the conditions of occupation and use by the residents. The planned case studies will be about contemporary works involving the partner GFC/Bouygues in London and Lyon, as well as two case studies on social housing, the Montée de l’Observance towers in Lyon and a housing scheme in East London. The second line of research is based on developing the research project for submission of an application to the ANR which I will lead during the next “Villes et bâtiments durables”* call for projects (AAP) in 2016. The project brings together researchers and professionals from various disciplines (geography, information technology, urbanism, architecture, law and sociology) to study the capacity, visibility, potential and possible uses of the urban canopy. Facing the pressures of environmental sustainability and steady urbanisation, roofs (built element of the urban canopy) could contribute additional capacity, constitute spaces for living, leisure and even production, agriculture and electricity, etc. The project envisages: 1/ cross-disciplinary reflection on the delineation of the urban canopy; 2/ an analysis of experience in using rooftops and developing rooftop spaces; 3/ an assessment of the capacity and visibility of the urban canopy and 4/ the development and testing of scenarios for reuse of roofs (in cooperation with the post-doctoral researcher in information technology).
Avec le programme de recherche SKYLINE (ANR), j’ai emmené un collectif de chercheurs dans l’exploration des enjeux paysagers des tours en focalisant l’attention sur une dimension particulière du paysage de la ville : le skyline. Du fait de leurs caractéristiques architecturales et de leur proéminence, les tours s’inscrivent dans le paysage matériel à toutes les échelles. En revanche, elles seules sont lisibles et impactent le grand paysage lu dans son volume. Elles y jouent parfois le rôle d’emblèmes de dynamisme économique et/ou de renouvellement urbain et traduisent un projet politique (McNeill 2005 ; Appert 2008, 2011, 2012). Par leur visibilité, de près comme de loin, elles font partie des édifices les plus contestés, ce au moment où le paysage est remobilisé à la fois comme cadre de vie et pour faire adhérer les populations aux projets urbains. Dans les villes européennes, la contestation des tours s’organise et s’amplifie : Londres (Appert et Drozdz 2010), Paris (d’Aboville 2015), mais aussi Séville, Vienne, Barcelone, Genève et même Saint-Pétersbourg sont concernées (Dixon 2009). La première partie du volume 3 consiste à caractériser le retour des tours en Europe et à en expliciter les ressorts. Les crises économiques qui se succèdent dans les années 1970 et 1980 et la montée des aspirations à la patrimonialisation réduisent l’appétence pour les tours nées du modernisme et de la phase de verticalisation des Trente Glorieuses. Elles sont rejetées à la fois par une partie de la population et les municipalités. Les décennies 1980 et 1990 sont celles d’un étiage marqué, à quelques exceptions prés. Après cette période d’étiage durant laquelle très peu de tours ont été construites, les villes européennes connaissent un regain d’intérêt pour cette forme architecturale et urbaine. Si le retour des tours est encore modeste en France, il atteint une ampleur sans précédent dans bon nombre de pays européens, témoignant tout d’un changement de contexte économique et politique. La nécessité de densifier les villes pour en réponse aux injonctions du développement durable fait quasi-consensus politique. Elle s’arrime sur une gouvernance publique-privée dans laquelle les municipalités devenues entrepreneuriales adoptent un agenda de croissance qui passe le plus souvent par des politiques visant à rendre plus attractifs les territoires urbains. Dans ce contexte, les tours se trouvent de nouveau légitimées. Elles sont synonymes de maximisation de l’usage du sol pour des fonctions résidentielles et commerciales et, lorsqu’elles sont localisées à proximité des nœuds de transport collectif, des signaux de centralité de réseau et de régénération urbaine. C’est une logique économique de l’offre qui prévaudrait : le choix des tours n’émane pas des populations et pas non plus nécessairement des municipalités. La promotion immobilière est désormais le principal acteur de la verticalisation. Les élus, tels que Gérard Colomb à Lyon, ou encore Ken Livingstone et Boris Johnson à Londres, conquis par la symbolique des tours, instrumentalisent les projets pour commercialiser leurs territoires. Les représentations des tours resteraient souvent complexes et polarisées. Les acteurs français interrogés dans cette partie ont confirmé l’hypothèse d’un traumatisme de l’architecture moderniste, des grands ensembles, parmi les praticiens, les élus et une partie de la population. Prenant acte de cette imaginaire négatif, les promoteurs ne tableraient donc pas sur un retour « spontané » vers les tours (Fincher, 2007; Mollé, 2016). Ils tendraient plutôt à remobiliser les imaginaires de l’élévation, de la domination et de la distinction, pour reformuler leur offre de logements et de bureaux verticaux dans des produits commerciaux qui associent habitat, vue et lifestyles. La deuxième partie du volume 3 revient sur les conflits paysagers suscités par le retour des tours en Europe. Les recherches scientifiques qui ont pour horizon la durabilité, ont longtemps laissé de côté l’impact paysager des tours. Promouvoir une ville durable ne se limite pas à identifier et mettre en œuvre les conditions d’une ville moins énergivore, il s’agit aussi de considérer l’altération potentielle des rapports des sociétés urbaines à leur paysage dans le contexte de verticalisation. Projection des activités, des normes et des règlements urbains, le paysage urbain est aussi un marqueur territorial, une signalétique du vivre ensemble et une ressource économique et sociale. Le retour des tours mobilise plusieurs dimensions du paysage. Dans la majorité des cas, le skyline - même s’il n’est pas toujours nommé - en tant que matérialité et représentation d’une vaste portion du territoire urbain lue dans sa verticalité, est au cœur de conflits entre acteurs économiques, praticiens, élus et associations. La deuxième partie du volume lui est consacré. Ayant acté et analysé les conflits associés au skyline (Appert, 2008, 2011 ; Appert et Montès, 2015), J’ai proposé de le décrypter, d’en stabiliser le contenu et les contours, et d’en discuter les représentations matérielles et mentales pour alimenter le débat public. L’horizon de la réflexion est aussi celui d’un appareillage des acteurs, municipalités et associations, confrontés à une accentuation de la pression à la verticalisation. La dernière partie du volume 3 constitue une programmation des recherches à venir dans le prolongement du programme ANR SKYLINE. Ces recherches futures s’inscrivent dans le champ de la ville verticale, que je continue à alimenter à travers deux axes distincts : l’habiter dans les tours (chaire industrielle HEVD Université de Lyon, labex IMU) et la formalisation et la mesure de la canopée urbaine (ANR CANOPY).
Fichier principal
Vignette du fichier
MANUEL_HDR_ToursSkylineCanopee.pdf (66.63 Mo) Télécharger le fichier
Loading...

Dates et versions

tel-01425959 , version 1 (12-01-2017)

Identifiants

  • HAL Id : tel-01425959 , version 1

Citer

Manuel Appert. Les formes de la métropole : du réseau à la canopée, de la mesure au paysage : Tours, skyline et canopée. Géographie. Université Lyon 2, 2016. ⟨tel-01425959⟩
1667 Consultations
910 Téléchargements

Partager

Gmail Facebook X LinkedIn More