The Gacka business zone is located in the southern part of the city of Osijek, along Gacka Street and in the immediate vicinity of the Southern Bypass and Knez Trpimir Street. The newly planned building is located on a joint plot of 13,500 m2, where two additional buildings are planned. The entire business zone is served by one shared parking lot and an underground garage. Responding to urbanism and the environment in which the office building is planned, the concept of permeation of greenery and construction was chosen as the main theme. The rigid core in the center of the building supplies the floors and is modeled and adapted with regard to the facilities that appear upstairs. The theme of permeation of greenery in the building is introduced by terraces on which seedlings with vegetation are located. The ground plan is interrupted on the longer side and the perimeter of the mentioned terraces on the east and west sides is receded. The office building has four floors, a basement, four floors and a passable roof. Public spaces due to the large circulation of people are located on the ground floor while on the upper floors are located private and semi-private offices with other accompanying content, taking into account the purpose of the building. The basement is wedge-shaped and reduced compared to the upper floors. The external dimensions of the basement walls are 40 m, 24 m, 38 m and 12 m, while the upper floors have been increased by 5.4 m along the longer side with the help of beams and are 45.4 m, 24 m, 43.4 m and 12 m. The building is performed as a spatially frame structure that is connected at the level of the ceilings with reinforced concrete slabs. The building is divided into three parts on the longer side by the core, and at the same time in the central axes are its walls which are connected with reinforced concrete frames.