Effect of Construction Methods on Building Envelope Performance

Abstract

The aim of this thesis was to investigate the effect of improved construction methods on improving thermal bridges and the thermal insulation properties of non low-energy buildings. The thermal envelope of a two level detached building was studied, and the thermal bridges of the building’s connection details and window installations were analysed. Each thermal bridge was modelled twice with Comsol Multiphysics; once as constructed with standard construction methods, and again with improved construction methods. The thermal bridge Ψ-values were calculated. Based on these values, the Passive House Planning Package was used to calculate the average U-value of the building’s thermal envelope for both the standard and improved construction methods. These average U-values were then compared to guideline values from the Finnish building code.

With improved construction methods, the thermal bridge Ψ-values showed an average of 51% improvement compared to standard construction methods and 62% improvement compared to the guideline values. This translated to a 17.6% improvement of the average U-value of the building’s thermal envelope compared to standard construction methods, and a 22.5% improvement compared to the guideline values. The results show the possible improvement to a building’s thermal envelope with improved construction methods for thermal bridges at connection details and window installations. The study can be used as part of a larger body of research when aiming to determine the best way to improve the thermal performance and energy demand of a non low-energy building.