Industry Foundation Classes (IFC), the buildingSMART open standard for BIM, is underused with respect to its promising potential, since, according to the experience of practitioners and researchers working with BIM, issues in the standard's implementation and use prevent its effective use. Nevertheless, a systematic investigation of these issues has never been carried out, and there is thus insufficient evidence for tackling the problems. The GeoBIM benchmark project is aimed at finding such evidence by involving external volunteers, reporting onin parallel, also with the aim of understanding whether one of the two offered more effective solutions that could possibly be borrowed by the other one in future developments. However, the final outcomes of the two different tasks are very specific for each standard and deserve to be presented and discussed separately, considering the specifics of each case. For these reasons, this article, which focuses on the results about the benchmark Task 1 (support for IFC), is written in tandem with Noardo et al. (2020c), which describes Task 3, covering the support for CityGML. In order to allow each article to be read on its own, the two articles share some information (i.e., Section 2 explaining the general context and motivation of the study; Section 3. 1 covering the initial part of the methodology about the entire GeoBIM benchmark set-up, and Section 3. 3 concerning some similarities in the methodology). One further article explores the parts of the project more directly related to the subject of integration, namely, conversion procedures and useful tools to georeference IFC models .