Architectural knowledge, representing an understanding of our built environment and how it functions, is a domain of research of high interest as much to laypeople as to architects themselves, researchers in cultural heritage in general and formal ontologists. In this work, we aim to provide an initial approach to the question of how to model architectural data in a formal ontology structure and consider some of the problems involved. This question is challenging both for the inherent difficulties of the discourse to be modelled but also for the lack of available structured data sources that would distinctly represent the architectural perspective proper, as well as for the contentious nature of the definition of architecture itself. We, therefore, take the step of exploring in broad strokes the possible approaches to architecture, tracing the notion of architecture as idea, process or thing from the literature. On the basis of this enquiry, we propose a model of some top-level referents of architecture using FRBRoo, an extension of CIDOC CRM that can be used to model creative processes. We argue that with the addition of only four classes to this model, to capture certain architecturally specific concepts and activities, we are able to provide an adequate high-level first approach to this problem. Further, by connecting this work to the existing extension of CRMba, which models built work as a system of relations of filled and unfilled spaces, there is a sufficient high-level ontological structure to begin to test for its utility to explore the issues of the relation between architecture as idea, process and thing. [ABSTRACT FROM AUTHOR]