Il borgo autentico di Osidda / The authentic village of Osidda

The historical village of Osidda, located in central-northern Sardinia, offers a valuable case study for the conservation and regeneration of marginal rural settlements facing demographic decline. Set on the Bitti-Buddusò granite plateau and surrounded by natural boundaries, Osidda has been continuously inhabited since prehistoric times, as evidenced by numerous archaeological sites such as nuraghi, domus de janas, and the sacred complex of Su Romanzesu. Although archaeological excavations have been limited, archival sources confirm the village’s medieval origins and continuous occupation, with a peak population in the mid-20th century and a marked decline to just 217 residents by 2022. The urban core, compact and responsive to the topography, preserves a traditional architecture characterized by granite masonry buildings aligned with narrow streets, generating a close relationship between built form and public space. Typological elements such as the 19th-century palattu and the altana reflect local adaptations and social stratification. Construction techniques, evolving over time, maintain strong ties to local materials and environmental conditions. A GIS-based methodology, developed in collaboration with the Department of Civil, Environmental and Architectural Engineering at the University of Cagliari, enabled systematic documentation of the historic fabric. The geospatial database integrates typological, material, and conservation data collected through direct surveys, photographic campaigns, archival research, and stratigraphic analysis. Thematic maps generated from this dataset support spatial analyses of degradation, transformation patterns, and historical layering. Historical cadastre analysis, especially of the 1939 register, further enriched the diachronic understanding of urban evolution. A 3D model derived from footprint heights provided an additional interpretive layer. Public buildings and services, including the town hall, library, and ethnographic museum, have been restored through EU-funded programs, supporting functional revitalization. Recent microclimatic simulations using ENVI-met software assessed outdoor comfort during peak summer heat, informing design strategies for climate adaptation that are consistent with the site’s morphology and identity. The case of Osidda exemplifies how integrated, knowledge-based approaches – combining architectural, environmental, and socio-cultural dimensions – can inform sustainable conservation strategies. These actions can serve as catalysts for broader territorial regeneration, positioning small historic villages as active, resilient, and climate-responsive communities.