The construction development of high-rise building is currently being widely expanding. During design, the building must be subjected by wind and earthquake loads, progressive collapse and many other forces. This paper present an evaluation of work of the reinforced concrete skeleton in a high-rise building with considering the process of erection. The subject of research is Idel Tower, the first high-rise building in the Republic of Bashkortostan. The building was calculated in two modes: a single stage and multistage. The modelling and calculation of building were performed in a software SCAD 21.1. The results showed that the values of vertical and horizontal displacement in a single stage mode was higher than in a multistage. There is a slight difference of internal forces in columns of the first floor between two design models. However, concerning pylons of upper floors the difference in stress values reached more than 30%.