Building energy efficiency refers to the practice of designing and operating buildings in a way that minimizes energy consumption while maintaining comfort and functionality. This can be achieved through various methods, such as using high-quality insulation, energy-efficient windows, and advanced heating and cooling systems. By reducing energy use, buildings can lower utility costs and decrease their environmental impact. Improving energy efficiency also involves the use of renewable energy sources, like solar panels and wind turbines, to power buildings. Additionally, implementing smart technologies, such as smart thermostats and energy management systems, can help monitor and optimize energy use, further enhancing overall efficiency.