Evaluation of a modular construction system in accordance with the Passivhaus standard for components

[Abstract] Passivhaus is an energy performance standard for buildings that has been deeply analyzed in the current scientific literature. However, the study of the Passivhaus standard for components and the use of certified components in the construction of new nearly-zero energy buildings have not been thoroughly discussed. Additionally, hygrothermal performance evaluations of components in accordance with this standard have not been fully presented to the scientific community. This paper addresses this topic and aims to evaluate the hygrothermal performance of a Spanish modular construction system of extruded aluminum, in accordance with the criteria for Passivhaus components, suitable for warm temperate climate. A three-part methodology was implemented, including hygrothermal performance simulations on fourteen connection details comprising wall, roof, window, and floor solutions. The initial outcomes reveal that only four connection details fully meet the Passivhaus criteria for components. Therefore, an optimization of the connection details is proposed to validate the Passivhaus suitability of the construction system. The connection details are redesigned to reduce thermal energy losses in the junctions and to eliminate the risk of interstitial condensation. Several simulation processes are then conducted and the new results are compared against the criteria for components, validating the Passivhaus suitability. The evaluation presented in this paper provided valuable data that enabled to later optimize and submit the construction system to the Passivhaus Institut to become the first lightweight metallic construction system for walls and roofs manufactured in Spain with a Passivhaus certification for warm temperate climate.