Environmental noise has become a large health concern in Europe with at least one in five people exposed to levels considered harmful to health. Additionally, prolonged exposure to excessive levels of noise has a negative economic impact.
The rapid development of urban areas makes the effect of noise pollution even worse. However, architects and urban designers who define the shape of a neighbourhood rarely give attention to this aspect. Decisions regarding the sound environment are often taken in the latter stages of design when the least design exploration is possible. Moreover, environmental acoustic involves complex urban physics which makes it more difficult for designers.

Therefore, in this master thesis, a parametric simulation workflow is developed which can predict the traffic noise in the early phases of design. The approach would be easy to use for architects and urban designers to overcome some of the main drawbacks of traditional practices.

The project followed five-step processes of research, development, validation, testing and optimization. To better understand urban noise, atmospheric acoustics, and how buildings affect sound propagation, a literature review was conducted. The parametric workflow was then created using Grasshopper, the visual scripting plugin for Rhino3D, in conjunction with other plugins such as Pachyderm and Ladybug.

After development stage, the parametric workflow is validated against on-site measurements and Geomilieu (environmental noise calculation software). Further, the simulation results from the design stage demonstrate that the tool can include urban microscale features like building shape, façade extrusions and materiality which can have an impact on reducing the traffic noise levels. It is found that the building shape of the lower levels may amplify or quieten the sound on upper levels. Façade extrusions have the least impact but variations in their positions and sizes may influence the results. It was further predicted that the green façade has a great potential to reduce reflected noise and lower the values inside the courtyard.

In addition, the findings of the optimization study show that the workflow may be used with other performance criteria and help to explore design solutions. Overall, the workflow can help identify the relationships between design aspects and acoustic performance in the early stages of design by taking into account simplifications and restrictions such as edge diffraction.