Artificial Intelligence (AI) is transforming optimization of energy efficiency in buildings and offices by improving renewable energy systems. AI systems have been able to optimize systems using predictive analytics and real- time data, which can result in large energy savings. Saving money, having lower energy bills, and paying less for upkeep are possible outcomes of optimization of energy in residential buildings and offices. Furthermore, severe environmental degradation factors such as air pollution and greenhouse gas emissions can be decreased with AI-driven energy efficiency in building and residential spaces. This research paper provides insights how optimizations can be performed in buildings by using energy efficiency techniques using AI techniques. Further, concepts such as Positive Energy Building (PEB), Building Energy Management Systems (BEMS) and Building Automation and Control Systems (BACS) have been thoroughly discussed.