The physical characteristics of an urban system are typically heterogeneously expressed, creating distinct neighbourhoods shaped by specific local features. Hence, spatially explicit expression of sustainability across the urban system is expected and should not be ignored. In this paper, we present an empirical study that explicitly accounts for the spatial heterogeneity of local-scale urban form features and the significance of a neighbourhood in the canton of Geneva, Switzerland. Our work first established a typology of urban form features, followed by the definition of local-scale functional neighbourhood boundaries using well-established criteria across the study area. An assessment of the sustainability of the resulting neighbourhoods revealed that significant differences can be observed between the different neighbourhood types across various components of urban sustainability. These results highlight the relevance, and argue for the importance, of incorporating local-scale approaches for more effective urban sustainability assessment to support urban planning and policymaking in the transition towards sustainability.