A multi-tiered data storage system for building management system (BMS) data includes a plurality of data stores including a first data store and a second data store. The system further includes a data access router configured to provide a consistent endpoint for the BMS data to an application that provides or consumes the BMS data regardless of whether the BMS data is stored in the second data store or the first data store, obtain a requested data object of the BMS data from the second data store in response to a determination that the requested data object is available in the second data store, and obtain the requested data object from the first data store in response to a determination that the requested data object is not available in the second data store.