Balancing Growth and Liveability: Evaluating Densification Means Through Scenario-Based Analysis in Zurich’s Altstetten-Albisrieden District

The increasing urban populace has propelled densification to the forefront of urban development initiatives. It is imperative to establish an urban planning strategy that thoroughly comprehends the effects of densification across environmental, social, and economic dimensions at both the district and city levels. In Switzerland, densification represents a legally binding policy objective aimed at fostering housing and job opportunities within established urban boundaries. Nevertheless, the challenge arises in accommodating population growth while preserving a high quality of life. Zurich exemplifies this situation, necessitating the accommodation of approximately 25% of the anticipated increase in both the resident population and associated workplaces, as of 2016. This study aims to investigate redevelopment approaches for urban densification and transformation within the context of Zurich, specifically examining the Altstetten-Albisrieden district. It produces five densification scenarios grounded in existing urban development initiatives, such as building replacement and extension, and assesses their impacts on urban forms and outdoor thermal comfort within urban areas at the neighbourhood level. Tools, including QGIS, Urban Multi-scale Environmental Predictor (UMEP), and R, facilitated data analysis, visualisation, and evaluation for each densification scenario, thereby aiding in the identification of potential challenges and strategies. The study concludes that appropriate measures for densification can significantly contribute to the development of liveable cities. In this context, the thoughtful design of building geometries is of paramount importance, as these elements play a crucial role in enhancing outdoor thermal comfort at the neighbourhood level and improving overall outdoor thermal comfort.