Metadata for 3D Models. How to search in 3D Model repositories?

In architectural education and practice, students, teachers and architects increasingly rely on online repositories with architectural information. This includes product model data, exemplary architectural projects and technical documentation, in a wide variety of formats. To be able to retrieve information from such repositories, they have to be well structured, preferably adhering to common classification standards. This article discusses how access to architectural repositories can be facilitated using optimized metadata. In particular, metadata describing 3D content is described, to improve structured searches. This research is elaborated within the MACE project.