In urban semantic digital libraries, users need to access heterogeneous types of resources in order to achieve a given task. Contextualisation is known to increase the understanding of documents. With the use of 3D city models, we propose an alignment model that correlates, using the semantic annotations, the different resources of the repository with the different objects contained in the 3D model. The result of the application of the algorithm, will then allow the user to picture the relation of the documents with the city objects but also the relation they have between each other, as a whole, and with this contextualisation, increase its understanding of the resources.