Architectural analysis of the main facade of the collegiate church of Osuna using high-density data collection

This study examines the collegiate church of Nuestra Señora de la Asunción in Osuna, Spain, begun in the early 16th century. It presents numerous geometric alterations and a strong material heterogeneity, making it difficult to understand the construction sequence, and thus its heritage value for possible restoration work. The study aims to determine whether these anomalies are original or the result of later interventions. We therefore analyze both the structural and geometric details of the facade panels, approaching the subject from multiple perspectives thanks to the methodological improvements on the field of heritage building survey. The analysis of mass data collection suggests that geometric deviations are due to issues that emerged in the set-out survey for the building works, and that the facade was constructed in a continuous phase during the 1530s. The study concludes that the facade likely originates from the workshop of master Diego de Riaño.