Méthodologie multicritère d'aide à la décision pour le renouvellement urbain à l'échelle du quartier

The present work develops a new methodology for assessing urban renewal scenarios at the neighborhood scale. Entitled URBIUS, this methodology seeks to meet the needs of municipalities in terms of planning for the development of their urban built fabric. It is now widely recognized that the urban population growth, along with the increase in the use of private vehicles, has led to a generalized urban sprawl. This land use is not sustainable in environmental, social and economic terms. Because most European cities are in this situation, it appears necessary to bring new developments within the urban built fabric, in order to raise their density. However, to rely on densification alone is not sufficient in order to move towards a more sustainable urban environment and to attract new residents looking for quality living spaces. Therefore, the transformation of the city requires a holistic vision, integrating different objectives. In this perspective, the neighborhood scale has been identified as an operational scale which integrates both the specific objectives of stakeholders taking part in the making of the city and the broader objectives of the city itself. In this context, this work seeks to contribute to the inward development of the cities in a qualitative way, by providing URBIUS, a new methodology for assessing the sustainability of urban renewal strategies at the neighborhood level. Prior to the creation of this methodology, an operational definition of sustainable neighborhoods has been developed. This one includes six goals: to ensure the feasibility of the urban renewal strategy, to provide housing to all residents, to balance the supply of jobs and housing, to save energy resources, to upgrade the local natural resources and to promote the balance between density and urban quality. Hence, the methodology is structured following these six goals and declines them in criteria and indicators for the purpose of the assessment. For each indicator, both quantitative and qualitative, assessment thresholds are set: a limit value and a target value. These thresholds are used to assess the strategies positively if the value is better than the target value, negatively if it is worse than the limit value, and uncertain for values lying between the limit value and the target value. However, in order to adjust the assessment to the specific potential of a neighborhood, an adaptation technique has been developed based on a dynamic approach. The assessment thresholds are adapted depending on the evaluation of the existing state of the neighborhood and on its underlying trend, that is to say the assessment of the neighborhood at a given time whereas no special action is planned. Finally, the new methodology is tested on four neighborhoods taken as case studies. The chosen neighborhoods have all a good quality public transportation system, with potential for densification and capacity to provide quality living space. They are located in the canton of Vaud, Switzerland: Lausanne, Prilly, Echallens and Yverdon-les-Bains. This work highlights the potential of urban renewal strategies at the neighborhood scale in the process of the transformation of the city towards greater sustainability and the contribution of sustainability assessment methodologies. In this sense, URBIUS is a relevant methodology to assist and foster sustainable urban renewal. Now it is up to the key stakeholders to undertake such efforts in urban renewal in a concerted and sustained effort.