The potential of vegetation for reducing road traffic noise at urban quiet sides

Reduction of noise from road traffic is one of the multiple benefits of employing vegetation in urban areas. In particular, application of vegetation to fa\ue7ades and roofs of residential buildings might be effective for increasing the quietness at the traffic-free side of these buildings, the quiet sides. The potential of reducing road traffic noise at the quiet side of buildings by a variety of vegetation-related measures is here studied by 2D and 3D full-wave numerical methodologies. The considered vegetation measures include wall vegetation systems, green roofs, vegetated low noise barriers at roof edges and combinations of such treatments. Green roofs appear to have the highest potential to enhance quietness at the traffic-free side of the buildings. For newly built roof systems, favourable combinations of roof shape and vegetation have been identified. Vegetated fa\ue7ades are efficient mostly when applied to narrow geometries with otherwise acoustically hard fa\ue7ade materials