The aim of this thesis is to enhance understanding of the role and impact of temporary populations in sparsely populated and peripheral areas by analysing second homes based on patterns of dwelling use rather than dwelling type. Specifically, the thesis aims to (1) close the gap in second home research on detached houses and alternative dwellings forms; (2) examine whether and how second homes contribute to increased activity levels and the presence of temporary populations in sparsely populated areas, within the context of multilocal living and post–COVID-19 changes; (3) assess the economic impacts of second homes beyond the tourism industry; and (4) investigate mobile second homes as an overlooked, semi-permanent form of accommodation and explore their prevalence within the second-home tourism sector. Through this approach, the thesis seeks to capture the actual scale, economic significance, and development potential of second-home tourism in rural regions undergoing structural transformation