This paper proposes a software architecture for creating and managing unambiguous descriptions of a Smart Building, allowing its Digital Twin to be deployed. These descriptions include static semantic structural description and dynamic time-series sensors data. Moreover, it is designed to be able to include data from various simulation tools, represented in the same way as sensors data. Thus, relying on these de- scriptions allow easy implementations of both monitoring and interaction tools that can the be interfaced with the Smart Building. Before the re- cent emergence of Smart Buildings, there was very few advantages in applying this concept to the field of construction and building manage- ment. Non-connected buildings don't produce real-time data, and can't be monitored nor operated from computer systems. But now that more and more buildings include IoT devices that allow them to expose data and services, the benefits of creating a Digital Twin to interact with the building, without interrogating the object itself, only by querying its Digital Twin, appears obvious. It then becomes crucial to be able to expose both a static description of the building's components (includ- ing IoT devices structural and functional description) and dynamic data that represent the evolution of the building's states over time. Copyright