The goal of this worktheses is to project and upgrade the existing residential building with composite material. The object of the half axis dimensions 7,3 x 50,63 m, is situated in town center of Zadar. The static analysis of the structures was carried out with the programming package Autodesk Robot Structural Analysis Professional 2015 on 3D spatial rod model. It is assumed that the existing ground floor is in good condition and strong enough for carrying the additional floor with same dimensions. The input data of the calculation were obtained through the activity analysis carried out in accordance with Eurocode 1 norm and its National additions. The calculation of the ports was conducted in accordance with Eurocode 3 norm. The activity analysis was carried out in regard to the effects of wind, snow, earthquake and in the usage load. The earthquake activity was taken into account due to the floor composite construction that is located on the height of 10,0 m measured from the ground. All elements of the construction were calculated in regard to the applicable combination of groups of elements in which they are located, in the way to meet the requirements of stability and mechanical resistance of the ultimate limit state and the serviceability limit state.