The mayor aim of modularCity was to support spatial planning processes with social dimensions and perspectives. The “Markthallenareal” of the city of Langenthal (BE) served as a case study and validation site. Therefore, the modularCity extension was developed to turn the planning software framework Urban ROJ Designer (URD) of the Swiss companies tsquare and Urbanis into a specialized tool for sustainable settlement development. In this context, interdisciplinary cooperation of technical and social sciences is of particular importance as to take economic, social and ecological aspects in equal measures into account. Sustainable planning processes therefore require technical instruments and digital platforms enabling transparent discussions and thus support consensus. There is urgent need to present people’s perceptions, demands and expectations on planning processes and projects to all the stakeholders being involved. modularCity started with reviewing and consolidating the most important social analysis methods and the specific indicators being used to evaluate the sociospatial quality in settlement development. In total, 16 relevant indicators were identified covering topics of social structure, building structure and structural density. In the second phase, the qualitative connections between urban spatial characteristics and sociospatial qualities were formalized by means of “Bedeutungskarten des Sozialraums” including sociospatial information relevant to planning like peoples’ perception and images of certain places. These were processed using unsupervised learning and self-organizing maps (SOM) to examine how different spatial units (e.g. residential blocks) appear in the attribute space. The modularCity plugin allows for both the processing and the integration of these “Bedeutungskarten des Sozialraums” in addition to the conventional zone and cadastral plans. With modularCity, a specialized participatory planning tool is now available which supports different kinds of expert-stakeholder collaboration and as such will greatly support planning processes. modularCity was used in the city of Langenthal (BE) in the planning project “Markthallenareal” in conjunction with an online survey. The results and key findings of that survey were then linked with conventional spatial data into a "3D socio-economic urban model". In addition, modularCity was also used in the municipality of Männedorf (ZH) supporting the BZO-Revision.