As for multi-storey industrial constructions, the Office buildings are composed of columns, beams and prestressed SP or TTP floor elements. Special inverted T-beams are used where the construction height is an important element. If necessary, the structures can be made with continuity between the beams, floors and columns, e.g. in constructions subject to the risk of earthquakes. Where column-corbels are not permitted for aesthetic reasons, Ergon can provide an incorporated, "invisible" BSF steel corbel. The use of high strength concrete (90 N/mm² or more) has become common practice in Ergon constructions. It reduces the dimensions, increases the spans, and gives greater flexibility and performance.