Problem statement. Cities hold a central role in global efforts towards sustainability, and integrating sustainability concerns into the governance of cities constitutes an increasingly urgent challenge. One avenue holding promise in this respect concerns methodologies under the banner of sustainability assessment. Indeed, various assessment initiatives, promoted by actors from local to global scales, have been developed in recent years, often based on sets of indicators that allow for the monitoring and benchmarking of cities across different aspects of sustainability. However, important shortcomings and gaps in knowledge remain, among them a lack of comprehensive guidelines for supporting the reflexive and contextually-relevant design of such assessments, and for ensuring their potential for influence in urban governance processes.

Research objective. This thesis aims to support the reflexive development of indicator-based sustainability assessments that are contextually appropriate and salient for local urban governance.

Methodology. In addressing the overarching research objective, the thesis was divided into three parallel research modules, each module with a particular thematic objective and dedicated research methodology. The first module used collaborative workshops among academics to investigate visions of urban sustainability. The second module collected a comprehensive empirical sample of urban assessments to analyze the indicators and conceptual frameworks in use in the field. The third module employed a case study methodology to develop an assessment approach aimed at enhancing the salience of such assessments.

Results. Across the three modules, the thesis makes conceptual, methodological and empirical contributions for different aspects of the design of indicator-based urban sustainability assessments. Firstly, it elaborates on the meaning of visions of urban sustainability, and provides tools and ideas for engaging with such visions in sustainability assessments. Secondly, the thesis elaborates on the conceptual frameworks and indicators available for the design of urban assessments, as well as on the critical areas where future initiatives can improve compared to current practice. Thirdly, the thesis contributes to knowledge for increasing the salience of indicator-based assessments for governance by proposing and demonstrating an assessment approach that systematically embeds the assessed indicators into their contexts.

Conclusion. Three transversal themes carry through the contributions and insights discussed in this thesis. First, the construction of an assessment of urban sustainability should be seen equally as a construction and clarification of the meaning of the concept, connecting concrete indicators to aspirational visions. Second, the choices related to the design of assessments should reflexively draw from the available options, in order to tailor them to specific contexts and purposes. Third, assessments should not be seen merely as technical exercises, but as occasions for creating narratives around sustainability that connect to the everyday challenges of relevant stakeholders. By contributing tools and insights for the design of assessments that acknowledge these three themes, this thesis encourages assessment practice that is both useful and meaningful for those involved in local urban governance, and that can thereby contribute to transforming cities towards sustainability.