As cities continue to grow and evolve, so must their digital aspects as Internet of Things (IoT) applications and devices grow in number, usage, and ability to measure the world around us. Traditional ways of representing information, even virtually, have started to become obsolete, as there is a need to handle both the static and dynamic properties of real life environments. In this paper, we model the dynamic properties of smart buildings, their structural components, and data produced from IoT devices using the NGSI-LD protocol. To facilitate the modeling of existing buildings and further enhance them with IoT aspects, we introduce the IFC2NGSI-LD parser which converts existing IFC-based data models to NGSI-LD. The usefulness of our NGSI-LD models towards creating smart spaces, is demonstrated by executing complex IoT queries using the NGSI-LD API. Such queries can be applied in large-scale buildings, as enabled via the IFC2NGSI-LD parser.