A building automation system (BAS) architecture is disclosed. The BAS comprises, in one embodiment, an architecture comprising a communication network and having a dynamic extensibility capability and an automatic configuration capability; an engine communicatively coupled to the communication network; and at least one control device communicatively coupled to the communication network, the control device being known or unknown to the engine. The engine can be adapted to selectively implement the dynamic extensibility capability to establish communications with and to control both known and unknown control devices. The engine can be further adapted to selectively implement the automatic configuration capability to determine at least one characteristic of both known and unknown control devices. A method of adding a control device to a building automation system (BAS) by dynamically extending and automatically configuring an architecture of the BAS is also disclosed.