This article examines the role of coworking and flexible workspaces in promoting sustainable spatial development in the non-metropolitan areas of Bulgaria. A mixed-method approach was applied, combining inventory enumeration, spatial classification, SDG-based sustainability assessment, and qualitative coding (open, axial, selective). A total of 74 coworking and flexible workspaces were identified across the six national planning regions, evaluated according to six analytical criteria (accessibility, seasonality, specialization, municipal administrative district, urban planning zone, building function) and assessed against five SDG-aligned dimensions (SDG 8, 9, 11, 12, 13). The results reveal uneven territorial distribution, strong concentration in major cities outside the capital, and emerging sustainable models in peripheral areas. Comparative SDG scoring and typological interpretation demonstrate three recurring models—Sustainable Reuse, Nature-Oriented, and Innovative/Experimental—each associated with distinct spatial and environmental characteristics. A metropolitan benchmarking exercise further contextualizes the strongest sustainability profiles. Based on these findings, a conceptual sustainable coworking model is developed for a nationally significant spa and climatic resort, illustrating how coworking can address regional disparities, support green transition policies, and reinforce territorial cohesion. The article concludes by outlining research directions related to digitalization, circular construction, environmental performance indicators, and feasibility assessments for non-metropolitan coworking development.
Ivanka G. Kamenova (Fri,) studied this question.