The Skyline : an operational concept for the governance of the urban silhouette in the context of the return of towers in Paris, Lyon, and London – SKYLINE

The first step was a spatio-temporal diagnosis of the construction of high-rises in European cities. The major trends and their variability among European metropolises were then identified. At infra-urban scale, London was specifically analyzed to identify the socio-economic, morphological, and regulatory contexts of the implantation of towers. A second step was the elaboration of an operational definition of the skyline, formalizing its grounding in the notion of urban landscape. This definition was the used to better identify and review the regulatory contexts that affect -directly or indirectly- the evaluation of tower projects in Europe and also -put into perspective- in the United States and in Japan. The last step was the elaboration of a series of conceptual and technical tools aimed at local authorities and associations which express their position on the landscape impact of tower projects.

Using and augmenting the Emporis database, we first developed a spatial analysis of the return of high-rise habitable buildings in Europe. To assess their location and the socio-economical context of their development, we have specifically evaluated and monitored the density, functions, population profile and accessibility of the areas in which they are constructed.

We then proposed an operational definition of the skyline embedded in the notion of landscape. A landscape approach allowed us to take into account the complexity of peuple-environnement relationships through the mediation of the visual. The skyline is political and social as well as material even geometrical.

To assess how people perceived the transformations of the skyline through verticalization pressures in Lyon and London, we developed 8 protocols of photo-surveys. The findings show how people value their cityscape and how current transformations are differently perceived among the public.

The geometrical approach to the skyline has been conducted through the use of 3D modeling and the development of indexes. Drawing from the work of APUR, Nijhuis et al. (2011) and Cassatella (2011), we managed to go further by first taking into account with a higher degree of precision the terrain but also the vegetation. We have then be able to identify and evaluate vantage points and views to simulate their transformation.

A new agenda for research on vertical urbanism based on SKYLINE project

The skyline projected is now being continued following seminal work in the consortium but also through dialogue with other researchers during events such as the Vertical City Conference held in Lyon in 2015. New questions and approaches have emerged that translated into new research projects.

Of relevance is the conceptualization of new urban dimensions such as the canopy, new ways of addressing technical objects of strong vertical dimension (the lift), using social and morphological approach such as usages or accessibility. The research conducted now by some members of the SKYLINE consortium and other colleagues on vertical urbanism is articulated around three themes : measuring, representing and visualizing the vertical city, living in the vertical city and regulating it.

Research that go beyond SKYLINE now are as follow :
- 3 research programs (CANOPY financed by Labex IMU, Chaire industrielle Habiter Ensemble la Ville de Demain, and HIGH-RISE financed by ANR).
- 5 thesis and several master research essays
- 4 special issues of academic journals : Geocarrefour, Built Environment, Metropolitiques and Géographie et Cultures.
- A book on planning for skyline is planned with colleagues from Politecnico Torino and members of the SKYLINE project.

2017 – Manuel Appert, Martine Drozdz, Andrew Harris, 2017, High-Rise Urbanism in Contemporary Europe, Built Environment, vol. 43, n°4.
2017 – Maxime Huré, Christian Montès, Manuel Appert, The governance of office tower projects in a European second city : the case of Lyon, Built Environment, vol. 43, n°4, pp. 520-538.
2017 – Christian Montès, Manuel Appert, Martine Drozdz, Imaginaires de la vi (ll) e en hauteur, Géographie et cultures, 102.
2017 — Manuel Appert, Maxime Huré, Raphael Languillon, Gouverner la ville verticale, Géocarrefour, vol 91, n° 2.
2017 – Raphael Languillon, Verticalisation des quartiers d’affaires et maturité urbaine à Tokyo, Géocarrefour, vol. 91, n° 2.
2016 – François Brégnac, Christian Montès, De la connaissance intime du lieu au contrôle marketing du paysage dans la construction du skyline d’une métropole. Retour sur La silhouette urbaine de Lyon (1990), Métropolitiques.
2016 – Raphael Languillon, La surrection du skyline de Tokyo : entre verticalisation opportuniste et effet de composition, Urbia, Lausanne, numéro spécial n° 3.
2016 — Martine Drozdz, L’espace du discours. Médias et conflits d’aménagement à Londres, L’Espace Géographique, vol. 45, n° 3.
2016 — Manuel Appert, The resurgence of towers in European cities, Métropolitiques, 19 février.
2015 – Raphael Languillon, The Tokyo skyline, or the hidden order behind opportunistic construction, Metropolitics.
2015 — Manuel Appert, Christian Montès, Réguler le skyline : une approche hybride associant chercheurs et praticiens, Lazzeri et al., Participation créative et paysage. Collection Espace et développement durable.
2015 — Manuel Appert, Christian Montès, Skyscrapers and the redrawing of the London’s skyline: a case of territorialisation through landscape control, Articulo, n°7.
– Manuel Appert, Christian Montès, The skyline research project. A new field of study in urban morphology: the metropolitan skyline. Urban Morphology, Vol. 18 n°1, pp. 75-77.

SKYLINE is an exploratory research project that combines collaborative and comparative approaches to investigate the political, economic and social dimensions of an increasingly contested urban landscape: the skyline. The project aims at filing the existing lack of conceptualization of the skyline, in a context where urban public bodies are considering lifting height ceiling limits while multiple conflicts have emerged across European cities against various projects of tall buildings.

As a fragment of the urban landscape, the skyline is the simultaneous staging of both past and present societies; it is a heritage and has increasingly become an economic asset. It can be deemed a vector of social cohesion or, conversely, of conflict, memory marker and a way to create and destroy economic value. These issues explain the increasing number of conflicts around the transformation of a set of urban views across European cities since 2000. Many actors are involved at different scales: the real estate market, architects, landscape architects, associations and sometimes UNESCO. This raises the issue of developing the skyline as an urban and political project that would balance the economic viability of the landscape, the diversity of urban identities and the promotion of a collective narrative in globalisation, where strategic planning is aimed at encouraging metropolisation, negotiation and participation. In the context of the sustainable city, SKYLINE intends to lay the principles to help regulating the skyline through the clarification of the strategies played out by the actors involved in its governance and to formulate the principles of sustainable governance for the skyline.

Researchers, practitioners and members of the civil society are associated in this project that intends to seize the recent debate over tall buildings in order to build an operational concept of the skyline and to set out the principles for its governance. Composed of a multidisciplinary team, SKYLINE has identified several goals. The first objective consist in defining the specific combinations of views and points of views that make up the skyline encompassing large parts of urban areas and embracing the materiality of urban societies as a whole. The other objective is to identify and understand the policy issues associated with the changes, conservation and representation of the skyline in order to formalise the skyline as a system. This effort of formalisation allows ultimately for both enriching and shaping the public debate on the impact of towers and tall buildings on the urban landscape.

Our project, positioned at both the “political problem formulation” stage - in the sense of an acceptable living together - and the quest for principles of governance, is methodologically innovative, linking researchers, practitioners and engaging members of civil society to conduct a participatory and interactive research. Those three groups are invited to construct, the concept of skyline and to define principles of governance.

To address these issues, we have chosen Paris, Lyon and London as our case studies as they offer different perspectives on the politics of the skyline in three different European regulatory and socio-economic contexts. The comparison and the identification of common features of the three cities allows for the shift necessary to establish the operational concept of skyline and fuel the exchange of experiences among researchers, practitioners and civil society.

SKYLINE is lead by EVS (Lyon2), with the following participants : l'EIVP-Ville de Paris, le LIRIS (Lyon1-2) et l'Agence d'Urbanisme de Lyon.
SKYLINE deals with an important issue in terms of the regulation of the urban landscape. The project as gained the support of Ville de Paris, The Greater London Authority, Westminster Council, Design Council CABE and from the world's biggest property valuation firm : CBRE.