The INSPIRE Data Specifications Annex III contains use cases encodings and a data model for Buildings. The devlopment of this schema was strongly influenced by CityGML, an Open Geospatial Consortium (OGC) standard developed initially in Germany by Thomas Kolbe, but now widely used around the world. However, there are differences that mean that applications developed for CityGML are not able to be used directly with INSPIRE Buildings data.
INSPIRE supports Level of Detail (LoD) 1-4 and includes four profiles, Core2D, Core3D, Extended2D, and Extended3D. It also includes six application schemas.
CityGML, available since March 2012 as Version 2, includes 3D geometry, topology, semantics, and appearance and supports LoD 0 to 4.
CityGML also supports a standard mechanism for adding extensions, called Application Domain Extensions (ADEs). There are several Application Domain Extensions (ADEs) that have been developed to extend CityGML to other domains. For example, I blogged about a basic extension UtilityNetworksADE that was proposed for city utility networks.
Today at the INSPIRE conference, Tatjana Kutzer gave a very germane presentation on how to use ADE to map CityGML data model onto the INSPIRE Buildings data model. She then showed practially how to use Safe Software's FME to migrate CityGML data directly to the INSPIRE Buildings schema. She gave a practical demonstration of doing that for LoD 2.
In response to a question from the audience, she said that the next version of CityGML will incorporate some of the specifications from INSPIRE Buildings that would move in the direction of harmonizing the two models.