Architectural Façade Retrofitting of an Educational Building to Reduce Traffic-Induced Noise Load

Noise pollution is a phenomenon that affects many large cities and is caused by several factors, one of which is traffic noise due to the high population density in urban areas. This paper aims to investigate three retrofitting techniques to reduce traffic-induced noise on the main façade of the architectural department building at Cairo University. Initial physical measurements recorded a minimum noise level of 63.9 dB(A), exceeding World Health Organization (WHO) standards. The first technique explores geometry manipulation by altering the inclination angles (5° and 15°) of the façade protrusions. The second technique evaluates two sound-absorbing cladding materials: green wall systems and coarse concrete tiling. The third technique combines the two approaches, applying the cladding materials to the optimized angles. Using I-Simpa as a computational simulation tool, the sound pressure levels (SPL) resulting from each technique were analyzed. The results indicate that the base case scenario with a 0.75-meter protrusion achieved an average SPL reduction of 1.7 dB(A) with a green wall and 2.4 dB(A) with coarse concrete. However, implementing a combination of techniques—including increased protrusion, inclination, and surface treatment—proved more effective, achieving a maximum SPL reduction of 2.8 dB(A) from the highest recorded level. This study demonstrates the potential of integrated retrofitting strategies to address urban noise pollution effectively.