The document discusses linking building data from multiple systems using linked data principles. Building information is currently scattered across different systems for energy usage, maintenance, finance, occupancy, and more. However, effectively managing a building requires a holistic view across all this data. Linked data provides a method to expose, share, and connect building data from different systems and technologies by identifying objects with URIs and linking information with relationships. This can provide new insights by linking domains like energy and resource utilization. The challenges of data interoperability, information granularity, interpreting data, and empowering actions are also discussed. A case study of applying these approaches to link operational and sensor data from a research building is also presented.