This lecture discusses the management of land use in Swiss law, focusing on the classification and reduction of building zones. It covers the conditions for establishing building zones, including the need for a 15-year forecast and the role of master plans in urbanization. The instructor explains the federal and cantonal methods for calculating land needs and the importance of ensuring that building zones are appropriately sized and located. The lecture also addresses the concept of reserved zones, which temporarily freeze land use to allow for future planning. Additionally, it delves into the principles of expropriation, highlighting the differences between formal expropriation and material expropriation, and the conditions under which property owners may be compensated. The discussion emphasizes the balance between public interest and property rights, illustrating the complexities of land management in Switzerland.