The aim of the paper, as of the previous research continuity, is to show the effects of the subgrade reaction coefficient modelling on the aluminium base grid structure and foundations. That kind of structure is more frequently used for the objects built on the faraway locations because of the small self-weight and small surrounding ground impact. Both factors direct influence on the investment. Commonly, the shallow concrete foundation system is supporting the aluminium grid construction, which is used as a base for the structure above. The above structure is modelled as load, while the soil is modelled through the subgrade reaction coefficient. The aluminium grid construction itself could occur in two extreme variations known as the rigid and soft grid. The test example deals with both forms and analyses their structural responses. The main influence on the structural response has contact with the underlying structure. For the subgrade reaction coefficient modelling the Se_Calc software is used.