Optimizing building energy efficiency: A precise BIM-Based approach for quantifying thermal bridges

This paper introduces a novel approach to assessing the impact of thermal bridges on building energy efficiency. The method involves calculating the total heat flow across whole building cross-section and subtracting the 1D heat flow of individual components to determine the Ψ-value for each building cross-section. Numerical simulations are carried out for all cross-sections of the building, which, when combined, represent the entire building. This approach provides a more accurate and faster approximation of the actual 3D heat flow, accounting for linear thermal bridges while excluding point thermal bridges. Two buildings were analyzed: a simple building to validate the method and a more complex multi-section building. For comparison, a classic numerical analysis was performed in accordance with the EN ISO 10211 standard, considering 13 thermal bridges for the simple building and 30 for the more complex one. The results indicate that the proposed method requires only three cross-sections (one horizontal and two vertical) to estimate transmission heat losses due to thermal bridges (H tr,TB ) with less than 2% error. These cross-sections, extracted from a 3D BIM model in Archicad, were selected based on their maximum dimensions in the horizontal and vertical planes. • Introduces a novel BIM-based method for quantifying thermal bridges in buildings. • Compares Ψ-values and transmission heat losses using the section method and EN ISO 10211. • Demonstrates efficiency with fewer cross-sections while maintaining accuracy within 2%. • Validates the method through analysis of both simple and multi-section buildings. • Provides a faster and more accurate approximation of 3D heat flow, excluding point thermal bridges.