In Austria as well as in many other states, the right to property constitutes a fundamental right protecting the free usage and disposal of property or other financially valuable rights. Obviously, transformative measures – set or initiated by the state – can lead to tensions or conflicts with private property of individuals. The right to property does however not establish an unlimited legal position, rather the state can interfere in private property rights in the public interest – as long as the interference is proportionate. The possibility of state interferences into one’s property expresses the so-called “social obligation of property”. The presentation engages with the social obligation of property owners concerning measures, which aim to transform the building stock.