If compared with reinforced concrete, the prestressed concrete is able to resist higher loads before cracks develop. As cracks reduce considerably rigidity of the element, the prestressed element can be regarded as rather rigid. The article compares the rigidity of the prestressed and non-prestressed foundations in two axes. Prestressed and non-prestressed variant is made for foundation structure of the rolling device in the Block Mill. A parametric study was created for investigation of impacts of the prestress on the foundation height. The savings of the concrete due to prestressing was also observed.