Achieving energy efficiency in buildings depends on how well the energy consuming equipment are controlled while providing ease of use and comfort for the occupants. There is a growing need to use modern smart sensors that can monitor environmental variables such as temperature, lighting, and humidity and send control commands to turn onenergy consuming devices such as lights and motors in a building. On the other hand, a control system needs electrical power and hardware/software for its operation which can increase total energy consumption and cost. Therefore, there is a trade-off between energy savings and additional hardware and software systems to control devices for heating, ventilation, air conditioning (HVAC), and lighting. This paper focuses on developing wireless embedded systems for sensory data acquisition to be used for efficient power management in buildings. In particular, we have investigated the feasibility of implementing an ultra low power and cost effective embedded sensor system using the Bluetooth low energy (BLE) technology.