In the past years different components of concrete buildings have been analysed using the finite element method computer package DIANA. Some of the results have been published. The first publication concerns the analyse of a prefabricated floor slab, consisting of prestressed hollow core elements, loaded in his plane. The second one describes the analysis of a prefabricated shear wall, especially the distribution of the shear stresses in the vertical joints between the elements. Both studies were parameter studies and carried out in order to develop simple rules to determine the dimensions of elements of a building in the preliminary design stage. This article gives a short summary of these studies and describes also the design of the bearing structure of a building of which the upper six stories cantilever over an existing old warehouse. One of the design options was the application of reinforced or prestressed concrete walls, providing cantile-vers of about 13 m. To determine the stresses and deformation DIANA has been used.