The planned project starts from the premise that second home use, i.e. occasional use of dwellings for vacation and recreation, is a strong factor in socio-spatial transformation. There is a constant growth of this trend in Croatia, whereby certain areas, or to be more precise, the coastal area is more exposed to second homes expansion. This increase in pressure of second homes and the tendency of this phenomenon to change and take new forms, especially under the influence of the expected growth of international second homes and disappearance of the hierarchy in the use of dwellings, have directed the planned project towards one question: are second homes only an obstacle, or could they be a source of opportunities, i.e. an additional impulse to the social sustainability of local communities in Croatia. The main objectives of the project are: 1) Identifying settlements in Croatia with an increased number of second homes; 2) Determining types of settlements in Croatia, and getting an insight into the connection of second homes to relevant sociodemographic and socioeconomic features of the settlers; and 3) Analysing how second homes affect the daily life of the local community, social structures and processes in it. These objectives direct the research towards combining secondary analysis of the census data and the analysis of the empirical data gathered through case studies. This will enable a deep insight into the way second homes affect the local social reality. Project team members: Geran-Marko Miletić, Anka Mišetić, Roko Mišetić, Krešimir Peračković, Saša Poljanec-Borić, Tomislav Smerić, Nenad Pokos, Sara Ursic, Mario Bara, Marica Marinović Golubić, Raseljka Krnić, Srdjana Urlić, Stanko Mirošević, Duje Radovniković , Mirjana Urlić, Katarina Mirošević and Boris Bučević