Revitalisation in Polish Medium-Sized Cities and the 15-Min Cities Concept: A Spatial Approach to Delimitation

Medium-sized cities play an important role in regional settlement systems as intermediary centres linking metropolitan areas with smaller towns and rural regions. Due to their relatively compact spatial structure, such cities are often associated with the principles of the 15-min city concept, which promotes accessibility to key services and public spaces within walking distance. Urban regeneration is an important instrument supporting sustainable development and improving quality of life in these cities. This study examines the relationship between legal regulations, spatial delimitation patterns, and the spatial distribution of degraded and revitalised areas in medium-sized cities. The research is based on a comparative analysis of qualitative and quantitative criteria, GIS-based spatial analyses, and accessibility modelling conducted for five cities in the Pomeranian Voivodeship using planning documents and statistical data, verified through field surveys. The results indicate a high degree of spatial continuity of revitalisation areas despite changes in legal frameworks and delimitation methodologies. Revitalisation areas remained concentrated mainly within historic city centres and their multifunctional surroundings, while degraded areas gradually expanded toward residential districts. The findings also demonstrate a strong spatial relationship between revitalisation areas and 15 min walking accessibility zones. The study provides useful comparative insights for countries developing formal urban regeneration systems.