Revolutionizing Residential Living: A Systematic Review of IoT Applications, Challenges, and Future Trends in Smart-Home Automation

Background: This paper aims to systematically review, based on a set of 125 papers, smart-home automation with IoT from the perspective of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The main evidence synthesis was conducted on empirical studies published from 2024 to 2026, with background studies as a supplement. Methods: IEEE Xplore, Scopus, SpringerLink, ACM Digital Library, and other databases were used in a systematic search. There were 81 empirical studies published from January 2024 to March 2026 that were included in the systematic evidence synthesis; 44 additional foundational and background works were added separately to provide a theoretical and contextual base, resulting in a corpus of 125 works. Due to significant methodological variation, results were summarized qualitatively rather than by meta-analysis, employing a structured framework of evidence tiers. Results: Real-world validation was limited across the reviewed corpus; reported savings were typically in the 15–25% range, with the majority of reported savings from simulations, testbeds, and/or short-term evaluations. Based on our review, six major gaps are identified: seamless interoperability, lack of real-world validation, weak security and privacy, generalizability, standardized benchmarks, and user trust. Discussion: Overall, the research roadmap and recommendations are given in an action-oriented, future-looking way for both industry and policymakers.