A multi-criteria approach to compare urban renewal scenarios for an existing neighborhood. Case study in Lausanne (Switzerland)

The post-industrial European city is characterized by dispersed urbanization, resulting in increased travel, substantial use of land, social disparities and costs that are unsustainable in the long term. Consequently, most European countries have set the goal of limiting urban sprawl by prioritizing increased density in already built-up areas. To achieve this goal, it is not enough to build new buildings in the urban lots that are still available. Efforts to increase the density of existing neighborhoods are also needed. These actions represent an important opportunity for ensuring sustainability through the simultaneous integration of socio-cultural, economic, and environmental criteria in our cities. This paper presents the evaluative approach applied to a case study carried out in the Fleurettes neighborhood, located near the train station in Lausanne, Switzerland. It demonstrates how carrying out a structured sustainability assessment of an existing neighborhood as well as a multi-criteria comparison of three possible scenarios using a tool recently developed known as SméO may truly help the decision-making process when choosing an operational strategy. 2013 Elsevier Ltd. All rights reserved. 1. Challenging the approaches to regional sprawl Urban sprawl, with its juxtaposition of poorly defined outskirts, often characterized by the compartmentalization of activities, is not consistent with sustainable development and its underlying longterm goal of balance [1e3]. In fact, urban sprawl represents an inefficient use of land, resulting in thewaste of these land resources and a potentially harmful pressure on the landscape [4e6]. Multiple studies have confirmed that the low density of suburban buildings and the typical distances between activities also lead to the significant energy consumption associatedwith using private motorized vehicles for transport [7,8]. Urban extension also results in increased environmental impacts and costs for the construction and operation of infrastructure networks [9]. From a socio-cultural standpoint, a dispersed city is characterized by a significant increase in socio-economic disparities. Imbalances may arise in core cities, which then have to deal with costs that are higher than their tax revenue potential, or in suburban communities, which are sometimes caught in a slow spiral of decline [10]. Faced with these issues, many stakeholders of the built environment are now seeking to increase territorial consistency [11,12]. In this context, urban densification strategies are a central issue. This shift in urban development towards sustainability also involves an increased coordination between urbanization and mobility [13,14]. In particular, this requires the use of greater densities in the most strategic areas near public transport stops [15]. The regeneration of derelict urban areas is a priority for creating these types of urban hubs, both mixed and dense [1,16]. Given the scope of the necessary reorientation of the post-industrial European city’s development towards sustainability, it is not enough to simply regenerate derelict urban areas or to build new operations in the remaining empty urban lots. Operations to renew existing neighborhoods are also needed. 2. The neighborhood scale Sustainability of the built environment is by nomeans restricted to questions regarding the location of buildings and urban densification. In other words, if density is to be considered as a necessary condition for sustainability, it is however far from being sufficient [17]. With a view to the overall quality of living conditions, the promotion of the return to the city raises multi-dimensional questions that must be incorporated into the processes of urban transformation. * Corresponding author. EPFL, ENAC, IA, LAST, LE 1 114/Station 18, CH-1015 Lausanne, Switzerland. Tel.: þ41 021 693 80 32; fax: þ41 021 693 08 85. E-mail address: [email protected] (M.G. Riera Pérez).