Automated building energy management systems are essential to enabling the development of mass-market, low-energy buildings. In existing and future buildings, the impacts of occupant behaviors contribute significantly to the total energy efficiency. As building technologies and materials improve, the relative impact of behavioral factors is more significant. We propose a general framework where building systems can share information in order to optimize performance. To be successful, such a system must be responsive, intuitive, robust, and scalable. As a first step toward achieving these goals, we present a prototype distributed control system for building energy management that uses wireless sensor network-class nodes. Using protocol independent multicast, sensors and controllers are allowed to efficiently share information in a distributed peer-to-peer fashion. Our prototype system achieved an energy savings of 7.1% - 14.6% by implementing a relatively simple control policy. Based on the results of this this work we have identified three key areas for future work.