This study explores the cybersecurity challenges associated with integrating Internet of Things (IoT) technologies into smart home systems. As IoT devices become increasingly common in residential settings, they offer significant contributions to energy management, comfort, and personalized living experiences through extensive data collection and automation. However, these advancements also introduce serious security vulnerabilities, particularly when IoT networks are interconnected within Distributed Smart Home IoT Networks. This research identifies the critical assets within these networks that enhance domestic life and examines how these assets can be exploited by malicious actors to launch cyberattacks. The paper presents a thorough threat modeling approach and outlines risk management strategies designed to strengthen the cybersecurity of these systems. Given the importance of cost and power efficiency in Distributed Smart Home IoT Networks, the focus is on leveraging both existing and emerging, low-cost defensive mechanisms to counteract these threats. Additionally, the paper discusses the implementation of layered security measures, integrating technological, administrative, and physical controls to mitigate risks. The study underscores the need for robust security protocols and standardized practices to effectively protect interconnected IoT environments, ensuring their secure and sustainable integration into smart homes.