How can digital sovereignty be achieved in the interplay between BIM and GIS? In this lecture block, a scientist, a practitioner and a system manufacturer will shed light on the role of open standards and open data for a sustainable, interoperable and sovereign digital society. Judith Maria Kirschler (University of Weimar) will begin by presenting scientific principles and current research approaches to the integration of geodata and building models. In the second part, Markus Hochmuth (Obermeyer) will use concrete practical examples to show how open standards are already being used successfully today. In the third part of the presentation, Sebastian Pache (Esri Germany) will conclude with an outlook from the perspective of a system manufacturer - focussing on technology and system convergence as well as on the understanding of digital sovereignty: What does it mean in concrete terms for providers and what responsibility does it entail towards society? All speakers are active in the buildingSMART Germany association, among others, and are committed to open, standardised and interoperable systems.