Deterioration patterns in preferred building orientations: Case study in Granada, Spain

• Strong correlation (85%) found between façade orientation and material decay. • Non-destructive methods used to assess 144 façades in Granada's heritage buildings. • Orientation-specific strategies are key for effective heritage conservation. To optimise the preservation of architectural heritage, this study investigates the relationship between facade orientation and the occurrence of specific architectural pathologies, aiming to statistically validate this connection. The research focused on 144 facades from 45 buildings in Granada, Spain, a city of significant cultural and architectural value. Non-destructive methods were employed to maintain the integrity of the heritage structures, including visual inspections, photogrammetric reconstruction, and pixel-based analysis. Quantitative evaluation used descriptive statistics and Spearman’s rank correlation coefficient for comparative analysis. The results indicate that each cardinal orientation is associated with distinct deterioration patterns, influenced by environmental exposure. Northern facades commonly exhibit discolouration, efflorescence, soiling, and biological colonisation by lichen and mould. Southern facades are more affected by fractures, cracks, and disintegration. Eastern orientations show moderate damage such as peeling, discolouration, and efflorescence, while western facades present peeling and vegetation growth as the most frequent issues. The Spearman correlation analysis revealed an overall correlation of 85.00%, confirming a strong and statistically significant relationship between facade orientation and the severity of pathologies. These findings validate the hypothesis that climatic factors linked to orientation are a key driver of material degradation. This research highlights the importance of tailoring conservation strategies to the specific environmental exposure of each facade. By acknowledging the influence of orientation, heritage conservation efforts can become more effective and context-sensitive, ensuring the long-term preservation of architectural identity.