When the leading telecommunications companies expand their 5G networks, the 5G installations are constructed on both existing sites and so-called greenfield sites (free rooftop sites). The site acquisition is the step most difficult to plan in the network development process because of the depleting resource of free roofs. The shared use of existing installations on rooftop sites is technically complex due to the required clearance area and negotiations with institutional owners are extremely complicated and lengthy. To ensure that the scarce resource of acquisition staff is not burdened by the identification of potential locations, we have already implemented and operationally tested a highly digitalised system for identification. Consequently, the tense situation with the resources can be eased, and there is a high degree of automation. Here we rely on geo-information systems in which different geo-layers are superimposed to provide site-specific information, such as the protection of historical monuments, schools, nursery schools, roof heights and much more.