Fostering sustainable urban renewal at the neighborhood scale with a spatial decision support system

Sustainable urban densification is one of the main challenges of European post-industrial cities. In Switzerland, a recent adaptation of the federal law on spatial planning reinforces the limitation of urban sprawl. Hence, public authorities are confronted with the challenge of exploiting the densification potential of the existing urban fabric. In order to develop realistic, yet ambitious projects, the neighborhood scale is considered as the most appropriate for urban renewal planning. At this scale, projects can follow a larger urban vision for the city, and at the same time, adapt to the specificities of the existing buildings, business, and inhabitants. Therefore, urban renewal projects at the neighborhood scale seem necessary for a sustainable urban development. In this context, adopting an evaluative approach offering a decision-making support appears relevant to contribute optimizing urban renewal projects. This paper presents a new spatial decision support system (SDSS): URBIUS, specifically developed for urban renewal projects at the neighborhood scale. It provides an assessment based on six sustainability objectives for existing neighborhoods. In addition, it offers assessment thresholds are adaptable for each neighborhood through a dynamic approach taking into account the actual situation of the neighborhood and its expected long-term evolution. Finally, URBIUS is tested on a case study, “Les Moulins” neighborhood in Switzerland, showing its potential to foster sustainable urban renewal at the neighborhood scale.

Urban renewal and sustainability

Maria Gracia Riera Perez

Many studies have shown that urban sprawl, which typifies most European cities, leads to: waste of land, increased energy demand, environmental impacts and high infrastructure costs. It is therefore necessary to renew the existing urban fabric to provide a good quality environment for a growing population, enable efficient management of economic resources, energy and environment. The aim of the project is to develop a decision support tool at the neighborhood scale, integrating sustainability into the dynamics of urban renewal projects through a multi-criteria assessment method including socio-cultural, economic and environmental aspects. This research project aims to promote a transparent, conscious and responsible decision-making, but also to contribute to the creative process of the future vision through a reliable and structured source of information on the neighborhood and its context.

2012

Quartiers résidentiels périurbains en transition : Comparaison multicritère de scénarios prospectifs à l'horizon 2050

Judith Elisa Drouilles

Since the Industrial Revolution, urban spaces have undergone a profound reorganisation in parallel with a transformation of society and lifestyles. Urban sprawl has become widespread in Switzerland, as in countless countries, due to continuous innovations in transport, exponential population growth, land speculation and the ubiquitous desire to live in a single-family house. This process has led to a dispersion of the city in rural areas, which today raises multiple questions regarding sustainability aspects. In response to the negative consequences of urban sprawl, the model of the polycentric compact city sets a reference for the expression of ambitious spatial planning policies. The context, very favourable to inward densification processes in areas well served by public transport, changes the perception of neighbourhoods of single-family houses by providing them with a status of unexploited land reserve. A growing number of projects is investing this emerging field of research to address the challenges of under-occupancy of housing, energy insecurity or the production of new residential areas. However, some neighbourhoods, located in peri-urban areas benefiting from a relatively poor public transport service, are on the margins of current investigations. Proactive approaches are still rare to provide answers to the challenges faced in these existing residential sectors. The aim of this doctoral thesis is to develop a decision-support framework to consider the future of peri-urban residential areas and their participation in the sustainability transition. Anchored within the European and Swiss contexts, the work questions the transformation potential of neighbourhoods by 2050. The approach is divided into four phases, the first of which consists in developing a typology of peri-urban neighbourhoods of single-family houses. This typology is the result of a method based on the successive reduction of the analysis scale, from the theoretical definition of peri-urban residential municipalities to the census of representative neighbourhoods in the Greater Lausanne area. The design of prospective transformation scenarios is part of the second phase of the research. The five scenarios â Caducity, Exclusivity, Opportunity, Urbanity and Mutuality â are derived from stagnation or transition trends of peripheral sectors, identified during interviews conducted among about 20 experts. The third phase consists in applying the scenarios to six existing neighbourhoods over a 35-year time horizon. The thesis does not have as its sole objective to carry out forward-looking work applied to concrete cases, by proposing a medium/long-term vision. Its innovative character also lies in the implementation of an experimental tool of building information modelling (BIM) at the scale of the neighbourhood to deal with the complexity related to the constraints of individual ownership. Considering assumptions of demographic and temporal calibration of projects, the fourth phase, of multi-criteria assessment, is enhanced by a dynamic analysis of evolutions. This assessment, developed in light of sustainability issues, highlights a considerable potential for improving peri-urban neighbourhoods, through energy-saving building renovations and the preservation of quality living standards. The path towards more sustainable futures also depends on the coordination of decisions at the neighbourhood level to go beyond the mere juxtaposition of individual interests.

EPFL2019

Quartiers résidentiels périurbains en transition : Comparaison multicritère de scénarios prospectifs à l'horizon 2050

Judith Elisa Drouilles

EPFL2019