00SMART is a Norwegian smart-building technology startup developing a vendor-independent Digital Twin and Automated Fault Detection and Diagnostics (AFDD) platform. Buildings generate large amounts of operational data from HVAC systems, BMS, sensors, controllers and IoT devices, but this data is often fragmented across different suppliers and systems. As a result, technical faults can remain hidden, energy is wasted, and building operators spend significant time troubleshooting manually. 00SMART connects these different data sources, validates and structures the data, and makes it usable for automatic fault detection, dashboards, Digital Twin/3D visualisation and operational decision support. Our goal is to help building owners and facility managers detect problems earlier, reduce energy waste, improve indoor comfort and make building operations more efficient. We are currently strengthening and expanding an existing working platform and preparing for further verification in real buildings.