City Layers: Citizen mapping as a practice of city-making

Today, cities are increasingly being transformed by data technologies and digital platforms at the macro level, causing gaps in the knowledge and understanding of our local urban spaces and processes at the micro level. How can we make future urban interventions more in sync with citizens needs? How can citizens themselves contribute to the spatial changes they want to see in their cities? The project proposes an innovative framework for city-mapping which centres on civic experience of urban space as an integrative way to contribute to more livable cities. The research aims to deepen the engagement between citizens and urban design by offering an app-based participatory tool that allows citizens to identify, record and reflect upon a range of different material and immaterial parameters in their cities, including noise, accessibility of public space, feeling of safety, aesthetics, amenities and weather resistance. The innovative city mapping app intends to become a means of communication between citizens and the city, with the aim of creating a new type of data that is collectively generated, managed and cared for. By recognizing and voicing their subjective experiences in specific spaces, citizens procure meaning and values, but also provide valuable data on how these spaces can be improved. Citizens` contributions are made available online for active use. This innovative mapping tool thus aims to reorganise individual observations into collective knowledge and brings out the strengths of citizen participation in urban design. The collected data is intended to generate a basis for a better dialogue between those who use urban space and those who plan it. That way, the research uses the citizen science approach as a radically democratic and urgent strategy for identifying the essential components which constitute a city.

The Top Citizen Science (TCS) project City Layers: Citizen Mapping as a Practice of City-Making investigated how people's subjective, site-specific experiences of urban space can be translated into valid and usable spatial knowledge. Conventional data collection methods often overlook the lived, emotional, and sensory dimensions of cities. This project addressed that gap by conceptualising, co-creating, and testing a new participatory method for mapping urban environments from the perspective of those who live in them. At its core is the concept of city layers that translates complex urban challenges into concrete, site-sensitive indicators - "layers" of urban space that citizens identify, map and visualize. Over two years, the project team operationalized this concept into a co-creation methodology that enables citizens to contribute and access information about the spatial dimensions related to climate, mobility, safety, noise, and more - thereby contributing to a new form of experiential urban intelligence. Through co-creation workshops, city mapping walks, and collaborative data interpretation, over 1,500 citizen scientists across Austria captured over 5,000 individual data entries. Their inputs were aggregated and visualized in a dynamic digital dashboard - an open-knowledge infrastructure that combines both qualitative and quantitative data into actionable, subjective maps of the city. This research resulted in three main scientific contributions: 1. A methodological framework for participatory, site-sensitive spatial data collection that centres on lived experience and emotional knowledge, validated through over 30 mapping sessions and 5 completed urban case studies. 2. A digital open-knowledge platform that functions as both a citizen engagement tool and a geospatial knowledge commons, tested with children, older adults, individuals with disabilities, and neurodivergent communities. 3. An epistemological intervention that reconceptualises urban data to include distributed, subjective, and context-specific insights, positioning citizens not merely as sensors, but as active co-producers of spatial knowledge. City Layers generated tangible scholarly and societal outputs. These include published proceedings (Responsive Cities Symposium 2023; Annual Conference on Architecture and Urbanism 2022), a submitted Q1 journal article (Urban Planning, 2025), and a keynote lecture at Places and Technologies 2025. The project received international recognition, including being shortlisted for Falling Walls Science Breakthrough of the Year 2025, winning the EU Sparks for Climate 2024 regional championship and being shortlisted at the EU finals, and being twice selected by Austria's OeAD for the Citizen Science Award (2023, 2025). The research team secured two follow-up EU-funded citizen science projects through the IMPETUS for Citizen Science programme. The research was featured at major science outreach events such as the Young Science Congress 2023, EU Researchers' Night Graz 2024, and Vienna Research Festival 2025. In collaboration with over 15 institutional partners, City Layers has since been integrated into TU Wien's Innovation Incubation Center (ic) as a high-impact, research-based innovation.