A lightweight solid structure is proposed in which concrete walls, preferably made of prefabricated concrete compound units, which are too thin to be subjected to loads as walls which are held on two sides are connected in the corners, such that parts of these walls become walls which are held on three sides and which bear the weight of the structure. The walls are connected to intermediate floors in a shear-resistant manner to produce T-beams which transfer the load onto the walls which are held on three sides. The walls and floors are connected by dovetail connections and grouting.
