Most smart home automation systems offer advanced features but remain expensive, complex, or narrow in focus. This paper introduces a cost-effective microcontrollerbased smart home system that integrates lighting, fan, and airconditioning control into a unified platform. By leveraging realtime sensor data and user input, the system dynamically adjusts appliances to balance comfort with energy savings. Unlike solutions requiring cloud connectivity or complex AI frameworks, the proposed approach uses a standalone Arduino-based controller and simple control logic to achieve intelligent automation. This simplicity allows significant energy savings-reducing lighting and HVAC power consumption comparable to more complex AI-driven systems yet attainable with low-cost, readily available components. The novelty of the system lies in its holistic integration of multi-appliance control under a single microcontroller with adaptive, user-centric operation. The proposed system has significant implications for resource-constrained regions by enabling affordable, sustainable automation that reduces electricity costs and improves user comfort without the need for expensive infrastructure. The result is a scalable and practical smart home solution that advances accessibility, sustainability, and comfort.