This paper presents the design and implementation of an Internet of Things (IoT)-based smart home model that integrates voice control and environment-based automation. The proposed system uses an ESP32 microcontroller as the main IoT communication module and an Arduino Mega 2560 for local hardware control. Several sensors and modules, including a DHT22 temperature-humidity sensor, MQ-4 gas sensor, rain sensor, and RFID authentication module, are integrated to support environmental monitoring, safety detection, and automated device operation. The system communicates with the E-Ra IoT platform to provide real-time monitoring and remote control through a web-based interface, while voice commands are implemented using Google Assistant. A physical prototype was developed and tested under normal operating conditions. Experimental results show that the system operates reliably and responds quickly to control commands, with an average response time of less than 1 second for basic device operations. The proposed model demonstrates the feasibility of building a low-cost and flexible smart home system suitable for research, educational applications, and small-scale residential environments.