A 500-year-old architectural monument is modernized
Construction work began in spring 2009:
At the end of April 2009, the scaffolding was erected and roofing and carpentry work started.
Further examination of the roofing, which was to be preserved, had revealed that frost and edge damage due to improper installation made it necessary to renew the roofing.
In order to properly execute the connections to the drag dormers, there was no choice but to uncover and renew these as well.
In the area of the sandstone facade surfaces, cracks were grouted and needling installed in accordance with the structural engineer's specifications.
The central gate on the north side was restored to its original arched opening with sandstone framing, and grout additions and veneering of damaged plinth blocks were carried out.
After the winter, work continued on the tower. By May 2012, the tower's exposed concrete façade had been completed to the extent that the Linit glazing could be installed, which consists of toughened U-glass shells supporting freely over a height of 6.50 m without a substructure.
Due to changes in fire protection requirements, the floor structures from the 1st floor to the 1st attic of the granary had to be modified:
On top of the remaining, historic floor boards, a 19 mm thick chipboard was laid, on top of that a fill of special slate chippings, on top of that tread-resistant rock wool boards, on top of that a 38 mm thick chipboard and as covering new floor boards were laid.
Solid wooden floorboards in various widths were chosen as the floor covering on the first and second floors of the museum. To anticipate the later natural patination, it was decided to pigment the protective coating lightly with gray hard-drying oil.
In the center of the building there was a freight elevator, which extended from the first floor to the second attic floor and for which the ceiling beams had been cut in the first half of the 20th century.
While the affected beams in the attics were now being replaced, this intervention in the substance was used to install the required staircase for the second escape and rescue route.
This staircase had to be fire-retardant from the first floor to the second floor.
To avoid visual impairment of the hall-like floors, it was decided to use transparent F-30 glazing, which was cost-intensive but met this requirement.
The countless connections to sloping headbands and uneven beam surfaces were particularly costly.
Intensive detailed considerations and individual trade-offs, including the omission of support profiles for the glass joints, led to a consistently transparent result, without interfering with the substance of the building.
The F-30 doors between the Kornhaus and the new stair tower also fit harmoniously and in terms of substance into the respective local situation.
Instead of the previous wooden doors, which were unsatisfactory in terms of quality, it was decided to use new wooden doors that are framed all around by a steel and glass construction.
The new elements are set back behind the late 19th century sandstone arch and serve both as natural lighting and as escape route doors.
In the design concept for the interior surfaces, it was decided at the beginning of the project to retain the existing mounts with green tones in their aged, worn condition and to clean them only carefully.
A lime plaster slurry was applied to the sandstone walls on the ground floor. Wooden elements were only cleaned, new parts were colored.
On the upper floors, the work was limited to cleaning the surfaces only, with minor retouching in badly damaged areas.
Starting in April 2013, the church painter was able to begin his cleaning work after the completion of the F30 walls and finished his work in October.
The surface, which had grown through signs of aging and use, now provides an excellent background for the planned museum use and also spatially a dignified setting for the future exhibits.
From July 2013, the first joint consultations and detail specifications then took place with the commissioned interior designers and museum planners.
During this time, the builder finally decided on a floor covering for the first floor. Instead of the previous slab flooring, a dyed utility screed was now to be installed.
The reasons for this were not only the costs but also the maintenance and the expected high degree of soiling of the sandstone slabs.
After the tendering for the new floor covering, the contract was awarded so that installation could begin shortly before Christmas 2013 and be completed at the end of January 2014.