Energy efficiency in buildings is increasingly recognized as a crucial factor in reducing overall energy consumption, lowering operational costs, minimizing environmental impact, and enhancing occupant comfort through optimized systems. In this context, the present study utilized a transient two-dimensional numerical simulation executed with COMSOL Multiphysics software to replicate the thermal behavior of a benchmark experimental setup, specifically the Minnesota Experiment. This study's methodology involved aligning the simulation parameters with the precise thermo-physical properties of the soil, as well as matching the indoor and outdoor climatic conditions observed during the experiment. To quantify energy dissipation accurately, the governing heat transfer equation for unsaturated porous media was employed, providing a robust framework for understanding thermal dynamics.

In order to enhance the simulation's accuracy, a novel mathematical method was developed to refine the thermal conductivity values of various building materials. This approach ensured that the simulated values closely represented real-world conditions, which is critical for effective energy management strategies. The primary objective of this research was to validate the simulation by rigorously comparing the computed temperature profiles with in situ measurements collected during the Minnesota Experiment.

The results revealed a compelling correlation between the simulated and observed temperature data, with a mean absolute error of only 1.5°C across the monitored period. The simulated temperature at the depth of 1 meter fluctuated between 12°C and 18°C, aligning closely with the observed values that ranged from 11.5°C to 17.8°C.

Furthermore, a detailed analysis of the heat fluxes at the soil-structure interface indicated an average thermal loss of 10.2 W/m² during peak heating hours, suggesting significant opportunities for improvement. This analysis enabled the proposal of effective strategies for reducing thermal losses, particularly through the slab-on-ground foundation, where potential reductions in heat loss of up to 20% were identified by optimizing insulation materials and configurations.

In conclusion, the study demonstrates that advanced numerical simulations can effectively replicate the thermal behavior of building foundations, providing valuable insights into energy efficiency. It is recommended that future research explores the integration of additional variables, such as moisture content and dynamic weather patterns, to further enhance simulation accuracy. Additionally, implementing the proposed insulation strategies could yield significant energy savings, contributing to sustainable building practices. Collaboration between architects, engineers, and environmental scientists will be essential for translating these findings into practical applications, ensuring that future designs maximize energy efficiency while maintaining occupant comfort.