Public participation has become an established instrument of responsive urban development, yet large-scale processes often struggle to combine broad accessibility, methodological diversity, and a clear pathway from citizen input to actionable outcomes. This paper examines “Frankfurt Next Generation” (FNG), a one-year urban future-visioning and participation process initiated by the Polytechnische Gesellschaft Frankfurt (PTG) and scientifically supported by HafenCity University Hamburg and TU Dresden. The project sought to engage a wide spectrum of Frankfurt’s urban society while, in parallel, activating influential organisational actors—termed “Impact Holders”—whose social, economic, and symbolic capital could support the implementation of emerging initiatives.
Methodologically, FNG combined multiple digital and on-site participation formats within an integrated process choreography. Building on an extended Double Diamond approach, the project developed a “Diamond Cascade” that progressively transformed initial impulses into urban future visions and, ultimately, concrete project ideas. Digital participation, a multilingual public placation campaign, qualitative coding, geospatial analysis, local co-creation workshops, and a final “Future Festival” were connected through defined convergence points between the broad stakeholder track and the Impact Holder track. The online campaign generated a substantial body of citizen input, including self-formulated future visions. In a subsequent qualitative analysis, the contributions were coded, grouped into thematic complexes, and ultimately structured into 14 “Vision Containers”, preserving the diversity of citizen perspectives rather than reducing them to a single overarching vision.
The process culminated in six “Lighthouse Projects”, including initiatives on climate adaptation, education, culture, health, and new spaces of opportunity. The findings indicate that FNG provides a proof-of-method for large-scale multimodal participation by combining quantitative reach with targeted qualitative engagement and by linking broad civic input to actors capable of sustaining follow-up activities. At the same time, the project revealed limitations in processing extensive qualitative datasets and in moving beyond activation and consultation toward deeper forms of co-design and conflict mediation. The paper therefore argues that FNG is best understood not as a standardized participation model, but as a replicable and adaptable process architecture for orchestrating heterogeneous participation formats, actors, and outputs in urban future-making.