Building façades optimization at preliminary design stage for outdoor noise mitigation

Noise pollution is one of the main issues affecting the inhabitants of contemporary cities, and architects are among the ones that are asked to find innovative solutions to the problem. However, outdoor noise mitigation is tackled only at the final stages of the design. The present study explores the possibility of integrating optimized façades design for outdoor noise mitigation into the preliminary building design phases through performance based design. Analysis have been conducted on a case-study building located in Torino (IT) through Rhinoceros 3D models, Grasshopper algorithms and Pachyderm Acoustic Simulation plug-in. The optimization algorithm allowed testing 3600 different façade materials combination, in order to maximize the environmental noise mitigation. A reduction of 1.2 dB was obtained by the optimization of materials in compliance with realistic constraints that are present when designing a building façade. Results of further simulations proved that sound absorbing materials on the street pavement and at the ground floor of the building have negligible effects for receivers placed above the ground floor, while variations in balconies geometries have a significant effect.