Influence of gaps under doors on the acoustic performance of wall and door assemblies separated by entrance halls

Although acoustic performance criteria for partitions are provided by the Brazilian standard NBR 15575-4 (ABNT, 2013), few studies have specifically addressed the acoustic behavior of doors and walls sets separated by entrance halls. Therefore, this study experimentally analyzed the relationship between the average dimensions of gaps under doors (M_Fresta) and acoustic performance, characterized by the Weighted Standardized Level Difference (DnTw). Data were analyzed using the R language, and results from linear regression demonstrated a significant negative relationship: larger gaps under doors correlated with lower DnTw values (estimated coefficient = -5.96; p < 0.001; adjusted R² = 0.62). Statistical modeling identified moderate residual autocorrelation due to the sequential data collection method; addressing this autocorrelation significantly improved the model fit (AIC reduced from 154.54 to 149.99). These findings reinforce the technical importance of addressing gaps under doors sealing to ensure adequate acoustic performance. Specific strategies, such as incorporating gaps under doors treatments into architectural designs, could aid compliance with regulatory requirements and enhance occupant comfort and privacy in multifamily residential buildings.