The Neighbor Effect Factor: Quantifying the Influence of Adjacent Buildings on Drag Force

Resumo

Urban areas have been increasingly expanding their built environment. Initially, buildings may be constructed in isolation; however, over time, new structures are inevitably erected nearby, potentially altering wind action in a non-negligible manner—conditions often not accounted for in the original design. This study evaluates the Neighborhood Factor (NF)—defined as the ratio between the drag force on a building in the presence of an adjacent structure and the drag force on the same building in isolation—based on experimental wind tunnel tests. The neighboring building, with the same dimensions as the main building, was positioned in four different locations, all aligned with the studied building. Three wind directions were considered: 0°, 45°, and 90°. For each configuration, mean NF values were computed from time series of drag force measurements obtained experimentally. Results indicate that the presence of neighboring buildings can significantly increase drag force, reaching values above 18% compared to the isolated case, depending on their relative position and distance. These findings highlight the importance of accounting for the aerodynamic influence of surrounding structures in wind load assessments for buildings.