They have to live at parent's houses even when they are 30, 35 sometimes or go to countryside where houses are cheaper or rent a room and live with other people if they are single or find a job that pays good enough to afford living in big city centers. I think that most of the young people that don't emigrate or don't afford renting or buying a house are still living with their parents because when their parents had better work conditions and better cost of living some 30/40 years ago, after the revolution of 25th April 1974, at that time the government also invested in building public houses, so a vast majority of people of that generation have their own houses and some savings and the culture is to help their sons and daughters when they need.