Demand response (DR) systems are the key component of the Smart Grid, which balances electricity generation by temporarily reducing or increasing demand-side consumption based on the real-time state of a power grid. In this study, we developed an infrastructure of BACnet-EnOcean based DR system for buildings. We describe an interface between two well-known international communication standards: BACnet and EnOcean. The BACnet-EnOcean Smart Grid Gateway (BE-GW) implements this interface, and we develop the EnOcean Load Control and Metering Device (ELCMD) to measure energy metering of each building appliance and control the load using wireless communications. Additionally, we develop an experimental facility to demonstrate how the BE-GW and ELCMD can be implemented in buildings for DR applications. Experimental results show that electricity consumption in the experimental facility can respond to real-time changes in the electricity price. We also measure the average communications delay of the energy metering service and load control service, and verify that the DR implementation satisfies the time-critical requirements of real-time DR services in buildings. (C) 2014 Elsevier B.V. All rights reserved.