The article focuses on the study of complex polycentric planning structures that are most characteristic of large multifunctional buildings. The question of the spatial typology of multifunctional public buildings is studied, various planning principles of access restriction are briefly considered. The planning system can be open to the external urban environment, i.e. extroverted, and closed, based on internal control, i.e. introverted, and also develop as a traditional system of barriers. The author describes the relationship between the protection and the permeability of spaces, including visual and physical. The issue of ensuring security and access control in such megastructures is investigated, it is concluded that their space-planning organization is built as a system of barriers dividing the building spaces into different access levels, which is provided by a communication framework.