Immigration and future housing needs in Switzerland: Agent-based modelling of agglomeration Lausanne

Abstract

Immigration accounts for 80% of Switzerland's annual population growth, and therefore profoundly impacts demographics, and the attendant housing needs. As there are different possible future scenarios of immigration that will impact urban transformation in Switzerland, we have developed an agent-based dwellings model that, with reasonable computing time due to the use of the computer architecture of graphical processor units, can simulate for a time horizon of decades, the annual evolution of millions of individually characterised households. This dwellings model is coupled to an agent-based population model that simulates millions of individual population agents. We simulate different immigration scenarios, up to 2035, in the Swiss agglomeration of Lausanne. It is shown that the building capacity of the city of Lausanne will reach a limit in 2022, subsequently leading to more rapid growth in the periphery of the agglomeration Lausanne. The construction of new residential dwellings consists primarily of smaller apartments that are more attractive to the demographic of smaller households; this demographic tends to move to the periphery. As families tend to move towards the city centre due to the availability of services, the city and periphery show opposite evolutions over time in the numbers of family households compared to numbers of singles and couples households. The periphery requires an increase in the number and typology of services targeted at the growing demographic of smaller households. Further as most workplaces are still be located in the city centre, the planned improvement of transportation infrastructure in the agglomeration should primarily focus on improved access to the periphery. These observations underline the profound impact of the typology of immigration on the demand for suitable housing, and thus on urban development.