Another significant milestone in the renovation of the listed Ravensburger Speicherhaus was celebrated today with a traditional topping-out ceremony. Around one and a half years after the ground-breaking ceremony, the real estate company Monvue, part of the Ravensburger Schulz Group, and the city of Ravensburg, together with numerous project participants, are paying tribute to the work carried out so far on the historically significant and challenging construction project in Escher-Wyss-Straße.
A lot has happened since the project was officially launched with the ground-breaking ceremony in December 2023. Various specialist companies spent almost the entire first year working on the expert gutting of the building, which was barely noticeable to the outside observer, and, above all, on the concrete renovation of the first three floors. The work on the supporting structure and foundations posed a considerable challenge to the schedule in some cases – and at the same time demonstrates the high quality and expertise of the specialist planners and companies involved.
Technology meets monument – renovation under special conditions
In particular, the condition of the approximately 100-year-old existing concrete was significantly worse than predicted, and during an 18-month construction phase, 54 column bases (18 of which were double), 54 joists, 200 secondary beams and 280 ceiling panels were repaired, among other things. In the process, 175 tonnes of construction waste were disposed of and 90 tonnes of existing concrete were replaced. The work was challenging and, in some cases, dangerous, as concrete pieces up to 1 m² in size broke off during the ceiling repairs, for example. As a result, almost 180 tree trunks were used to secure the building, and the safety coordinators ensured that, despite the adverse conditions, no personal injuries have occurred to date.
The foundations of the historic building were also unclear at first. No fewer than 30 soundings finally provided the necessary certainty. For two new development cores, a large-scale soil replacement was carried out with a lean concrete layer over 1 metre thick. A total of around 1,000 tonnes of broken concrete was removed from the ground, along with an additional 3,500 tonnes of construction waste from the interior and exterior, using 250 truckloads, and disposed of in accordance with regulations.
To protect against rising damp, almost 1,400 holes were drilled into the outer wall at floor slab level at intervals of 10 cm and sealed with 4,500 kg of cavity filler and 2,000 litres of injection material. This was a task that required the utmost precision.
Around 13 tonnes of wood were professionally dismantled from the historic roof truss. Around 90% of the original components, including purlins, posts and rafters, were preserved. In addition, around 165 new wooden elements have been added and each rafter has been lashed down. For the renovation of the half-timbered walls, large parts of the infill had to be removed. The old half-timbered bricks were removed, cleaned and almost completely re-walled into the half-timbering. This was a highly complex task, but one that was appropriate for a listed building.
As could then be seen from the outside, in addition to the self-supporting façade scaffolding above the southern front building, a free-standing working scaffold was erected at a height of 17 metres for the work on the building, supported by two 22-metre-long steel girders. This complex measure was necessary because the historic roof could not be used as a support due to its lack of load-bearing capacity.
With the help of deformation-compatible measurements, it was determined that the storage building had tilted approximately 30 cm from northeast to southwest due to historical settlement. All new floor structures therefore had to follow this inclination in order to ensure future use. To ensure the correct height, over 150 metre marks were set.
In the meantime, work has also begun on renovating the windows. Fifty-one windows from the original construction period are being renovated in accordance with conservation guidelines, while a further 132 windows are being rebuilt based on plans faithful to the originals and fitted into the existing building.
At the peak of construction, up to 30 skilled workers from a wide range of trades were working simultaneously on the construction site – a logistical feat due to the condition of the building, which was made possible by the high level of motivation of the contracted companies and specialist planners.
Client and future tenant satisfied with progress to date
Sven Schulz, sole shareholder of the real estate company Monvue, is satisfied: ‘What has been achieved here since the beginning of 2024 is remarkable. The combination of historical respect, structural substance and modern requirements is a great challenge – but also a great opportunity for Ravensburg. I would like to thank all the craftsmen, planners and partners for their commitment and hope that we can maintain this impressive positive momentum until completion in October 2026.’
Mayor Dr. Daniel Rapp adds: ‘The Speicherhaus is a key project for Ravensburg – historically, functionally and architecturally. Today's celebration is a clear sign that, despite all the challenges, the work here is being carried out to the highest standards. Our employees can already look forward to modern and attractive workplaces.’
Next steps
With the successful completion of the roof work, the installation of the new stairwells and lift cores can now begin. This will be followed by the interior construction phase. In addition to the technical building equipment, the floor structures will be constructed and the façade and outdoor facilities will be finalised. Completion has been delayed by six months due to the complex renovation of the existing building and is now scheduled for October 2026.
The renovated building will then serve as a modern workplace for up to 200 city administration employees. With around 5,600 square metres of space, new, energy-efficient working environments will be created in accordance with the DNGB Gold Standard, complemented by potential catering facilities on the ground floor.
