The subject of the thesis is an architectural study of the reconstruction and extension of the "Centrum" department store in Brno. It is a dominant building designed by the famous czech architect Vladimir Karfík, which is located at the Urban Conservation Area Brno. Object wasn´t realized with the full extent of the original proposal, so in the project is planned a completion of it. The new solution respects the historical quality of Urban Conservation Area Brno with a concurrent view of the location on the lucrative land in the city center. The architectural concept is based on a return to the original idea of the architect and the addition of my own creative contribution within the extension of the new floors. Draft of the extension is intended so that the individual parts of an object communicate with each other, but they are easily recognizable as well. This idea was filled by both parts linked together visually by horizontal lines and ripple, which is used on balconies of the extension and behind the facade of the current building by shielding walls. However it is emphasized the contrast between an enclosed mass and a free-flowing space. The existing part of the building is used especialy as a leasable area of trade and services. On the upper floors there are areas of administration. Furthermore, there will be a restaurant and cafe with exhibition galleries and apartments are designed on the new added floors. The building is adapted to use by person with limited mobility. Newly added uses in the object will increase the attractiveness of the building and its surroundings.