Civil multi-story structures are used as office buildings or residential buildings. The central pillars on the ground floor of the civil structures will have the largest gravitational load and implicitly will be the pillars most stressed in compression. In this paper, the authors propose to increase the critical buckling load of the central pillars on the ground floor in the event that it is necessary to strengthen these pillars, due to the change in the purpose of the building and the modification of the loads on the floors. To increase the buckling load in the case of these columns, it is proposed to increase the moment of inertia of the columns on the base region. To highlight how the critical loss of stability load changes, a theoretical model is made for the column with constant section and another for the column with variable section in steps. Finally, the results obtained for the critical load will be compared and it will be highlighted what is the increase in buckling load for the pole with variable section in relation to the pole with constant section.