This project is a study about the renovation and reconstruction of the existing building in Belgrade. The existing object in Bezanijska Kosa (Pere Segedinca street) was taken as an example on which the reconstruction project design was made. The reconstruction of the particular object includes adding new spaces on the bigger existing facades, reorganization of the space in the way that it be more functional, giving more space to the existing one, changing the existing thermal materials and windows with the new ones that have better thermal performances and adding solar panels on the roof with the idea of making the building sustainable. Beside makeing the new visual identity to the existing object, the main goal was making the object more sustainable with better reduction of the heath losses. At the end, the analyses was made by completing the energy efficiency certification of the building.