Germany – Architectural, construction, engineering and inspection services – Stadt Göttingen - Neues Rathaus - Sanierung und Instandsetzung der Tiefgaragen - Objektplanung und Tragwerksplanung

The New Town Hall of the City of Göttingen is located at Hiroshimaplatz 1 - 4. It consists of several building sections, which are composed of a high-rise tower and a multi-storey annex (hereinafter referred to as 3. BA). Both building sections are connected at ground level. The subject of the planned measure is the renovation of the defective sloping concrete of the underground car park in the 3. BA. For better understanding, this area will be referred to as "Underground Car Park A" hereinafter. The New Town Hall has a second underground car park, which is located in the so-called 1st construction section, under the tower. For better understanding, this area will be referred to as "Underground Car Park B" hereinafter. Here, extensive renovation and maintenance work must be carried out.

1. Renovation of the defective sloping concrete ("Underground Car Park A")

Underground Car Park A was constructed around 1978 and comprises three levels: the basement (1st basement) and two lower basements (2nd basement and 3rd basement). In some areas of these underground car parks, renovation work has been started on the reinforced concrete structure, the technical systems and the sloping concrete structure. After the sloping concrete was installed in the two lower basements, significant voids and cracks were detected. Expert reports were commissioned, which document composite failures, voids and cracks and name several possible technical causes. However, no final legal attribution of responsibility or liability is connected with this presentation or the submission of these reports. The previous planning contract was terminated prematurely. However, the other project participants have declared their willingness to continue to cooperate. The subject of the project is the planning and supervision of the rectification of defects and the continuation of the started renovation work. According to the cost estimate of the contracting authority, renovation costs of approx. 2.08 million EUR gross (KG 300) are expected. The further, not yet executed services of KG 400, which will arise in the course of the rectification of defects, are estimated at approx. 135,000 EUR gross.

2. Renovation area tower ("Underground Car Park B")

Similar to the preliminary work already carried out in the 3. BA, a similar pattern of damage is present in the renovation area of Underground Car Park B, which has not yet been processed in terms of planning or execution. After water had penetrated the expansion joints and concrete had flaked off, an inspection of the structure was carried out in 2020. This revealed a serious excess of salt or chloride contents. Further defects were identified, including improper installation of the installed drainage system. The subject of the renovation is to be the removal of the asphalt, the preparation of the concrete, preliminary work and corrosion protection of the reinforcement. Supports on the load-bearing structure are to be provided. The technical equipment of the underground car park includes, for example, the lighting, emergency lighting, roller shutters and barrier systems as well as the sanitary and ventilation systems and, in addition, the sprinkler system. The ventilation system will be replaced without replacement by a smoke extraction system. Specialists will be entrusted with the dismantling and the restoration, in accordance with the state of the art, of this technical building equipment and other installations. The coordination of these other trades must be taken into account in planning and execution. In this context, noise-intensive work is to be bundled as far as possible due to the workload in the tower. The costs for the renovation work of Underground Car Park B are estimated at approx. 9.95 million EUR (KG 200 - 700) gross.

3. General framework conditions

Both the costs for the planning services and the costs for the commercial implementation are to be kept separate from each other. Planning services for Underground Car Park A are to begin immediately after the order is placed. It is assumed that the planning phase will take approx. 4 months and the execution phase approx. 6 months. Completion of the project is targeted for the 4th quarter of 2027. Planning services for Underground Car Park B are to begin in April 2027. It is assumed that the planning phase will take approx. 12 months and the execution phase approx. 21 months. Completion of the project is targeted for early 2030.