There is a need to develop cost-effective and compact solutions for Smart Home monitoring. Existing monitoring systems depend on continuous power sources to support the operation of sensors and electronics modules used therein. In this article, we present three simple battery-free, Radio-Frequency Identification (RFID)-based solutions for real-time monitoring of the orientation of an object using a tilt sensor based on a metallic bead, an entry detection system utilizing a reed switch-based proximity sensor, and a temperature crossing event detection using a thermistor. All sensors are integrated with individual passive RFID tags. The proposed sensing mechanisms were also combined to achieve multi-modal logic sensing operation. Active events (change in position, motion, and temperature) would alter the state of the corresponding flexible RFID sensors to transmit warning signals wirelessly to an RFID reader, realizing a simple RFID-based Smart Home network. The proposed platform has been validated through extensive simulation and actual measurements.