This paper investigates the use of Doppler radar sensor for occupancy monitoring. The feasibility of true presence is explored with Doppler radar occupancy sensors to overcome the limitations of the common occupancy sensors. The common occupancy sensors are more of a motion sensor than a presence detector. Existing cost effective off the shelf System-on-Chip CC2530 RF transceiver is used for developing the radio. The transmitter sends continuous wave signal at 2.405 GHz. Different levels of activity is detected by post-processing sensor signals. Heart and respiratory signals are extracted in order to improve stationary subject detection.