During the last three years, a real break-through took place in Belgium for the construction of tower buildings in precast concrete, now already up to 130 m high and with 37 storeys. Up to the nineties, precast concrete was not much used in this market sector. During the following decade, the precast intervention was in many cases limited to prestressed hollow core floors, to be integrated in a steel frame structure. The steel profiles were fire protected by concrete or other materials. Recent developments at one of the leading Belgian precasters, Ergon, has drastically changed this situation. Precast concrete components are now being used in an extensive way, also for the structural frame of high rise office buildings.