A building automation system (BAS) comprising a plurality of end devices, at least one communication network, and a protocol-independent server engine. The end devices are each associated with at least one of a space, a system, or a subsystem for at least a portion of a building or a campus. The communication network supports a plurality of communication protocols and communicatively couples at least a portion of the plurality of end devices. The server engine is communicatively coupled to the at least one communication network and includes means for selectively implementing a dynamic extensibility capability for the BAS that establishes communications with and control of the plurality of end devices over the plurality of communication protocols, and means for selectively implementing an automatic configuration capability for the BAS that supports addition of end devices to the plurality of end devices by determining at least one characteristic of each end device. Methods of establishing communications with unknown end devices in a building automation system (BAS) based upon metadata descriptors provided by known and unknown end devices are also disclosed.