High energy consumption in buildings stems from inefficient thermal distribution and systems. Proper building envelope design is crucial for minimizing energy consumption while maintaining comfort. Expanded polystyrene significantly reduces heat losses compared to uninsulated walls, leading to improved thermal performance. In summer, both walls and roofs exhibit higher thermal flows, while in winter, heat dispersion is reduced. Expanded polystyrene insulation demonstrates significant efficacy, reducing heat losses by 90% and 47%, respectively, compared to structures lacking thermal insulation in walls. The study emphasizes the importance of optimizing the building envelope to enhance energy efficiency and comfort.