This paper focuses on calculating the main loads of prefabricated low-rise buildings from sandwich panels of arbitrary structural elements and connections in the form of a rigid spatial system. The main objective of this research are the theoretical and experimental substantiation of rational parameters of quickly erected transformable low-rise buildings from sandwich panels for the development of optimal design solutions to ensure spatial rigidity. The research used empirical research method - observation, experiment, measurement, comparison and analysis. The quickly erected transformable low-rise buildings of sandwich panels, like a prismatic shell consisting in the transverse direction of two closed rectangular contours, can bear an arbitrary power load. Determination of the cost of materials for additional structural elements in the form of ties (embedded parts), combining the individual elements in a holistic design that provides spatial rigidity of the structure. © Published under licence by IOP Publishing Ltd.