Towards sustainable urban renewal at neighborhood scale
The public defense of the doctoral thesis presented by Maria Gracia Riera Pérez took place on April 10 at Ecole polytechnique fédérale de Lausanne (EPFL). Conducted under the supervision of Prof. Emmanuel Rey, Laboratory of Architecture and Sustainable Technologies (LAST), this research led to the development of a multi-criteria methodology for urban renewal at the neighborhood scale. Called URBIUS, this new approach seeks to meet the needs of municipalities in terms of planning for the development of their urban built fabric.
The post-industrial European city is characterized by dispersed urbanization, resulting in increased travel, substantial use of land, social disparities and infrastructural 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, new operations on disused or unused urban areas are however not sufficient, urban projects on existing neighborhoods are also required. In a sustainability perspective, urban renewal goes beyond the issue of density. It has to integrate socio-cultural, economic and environmental aspects simultaneously.
Given these facts, the doctoral research conducted by Maria Gracia Riera Pérez allowed the development of an original approach leading to a new tool for the structured diagnostic of an existing neighborhood and the multi-criteria comparison of different scenarios of urban renewal.
Four neighborhoods were chosen as test applications for their good quality of public transportation system, with potential for densification and capacity to provide quality living space. These four areas are located in four different types of municipalities: large center (Lausanne), secondary center of a large center (Prilly), medium center (Yverdon-les-Bains) and town in the outskirts of the agglomeration (Echallens).
For each of these municipalities, a neighborhood was selected and three urban renewal scenarios have been developed following a different scenario. The first scenario suggests an evolution in continuity, that is to say that densification is made by interventions on land plots taken individually, according to a new regulation authorizing a greater density. A second scenario implies the intensification of the land use by readjusting and grouping plots and, by the way, allowing more coherent urban forms. Finally, a third scenario proposes transformation in order to suggest a new urban form adapted to the site. This scenario implies an important work of land readjustment.
These test applications have enabled to enhance URBIUS relevance and ability to highlight potentials and challenges of different scenarios, while accommodating the specificities of each site.