Increase in large size
17.08.2021
With careful renovation and a large-scale addition, the venerable cardboard and paper mill in the Bern suburb of Stettlen is being transformed into modern living space and a hub for startups and many creative and bright minds. Armin Schawalder will present the project at the Forum Holzbau in Cologne on October 20.
At one time, over 250 employees produced cartonboard for the whole of Switzerland. Up to 500 tons of of cardboard left the industrial site every day before those responsible shut down the machines in 2010.
Bernapark AG transformed the former cardboard factory into a quarter with different different uses. In doing so, they relied on a differentiated combination of temporary use, conversion of old factory buildings and generous extensions.
The one hundred meter along the tracks of the RBS railroad and the building B, which was set back from the Building B had to remain standing. The two structures were carefully renovated and converted into loft apartments, creative spaces and small industrial areas - and extended with a two-story addition. In order to minimize the floors below as little as possible, the structure was built as a timber frame construction. Timbatec was responsible for the statics of the which today houses 133 apartments and maisonettes, responsible.
Structural concept
The factory building - a solid structure made of
of reinforced concrete and masonry - consists of a 140-meter-long beam and a
70 x 40 meter building. Both structures are 18 meters high and were raised by
two floors, or about six meters. The additional storey must therefore
withstand correspondingly high horizontal effects from wind and earthquakes.
Structural engineers usually define the
points where forces from structures are transferred to the foundations. Not so
the Bernapark: Here, the existing building specifies where the forces from the
can be diverted. This results in a structural concept with many
This results in a structural concept with many changes, different load-bearing directions and, in some cases, large spans.
Due to the different vibration behavior of solid and wooden structures
the stiff substructure, higher loads were also imposed on the timber construction with regard to earthquake
higher loads were applied to the timber structure.
The two additional floors are built in
bulkhead construction, whereby the majority of the bulkhead walls are load-bearing and are
and for stiffening the building on both sides. The
ceilings and the roof are mostly spanned transversely as box girder elements.
Construction
Wall construction
The timber construction is also partially visible on the façade.
the facade: In the area of the terraces, the facade is adorned with 20 millimeters of
spruce/fir decorates the facade. Other parts of the façade have been plastered to reflect the existing
the existing industrial character. In this way, the addition is
harmoniously integrated into the existing structure. As plaster base for the 8 mm plaster layer
are 60 mm rock wool insulation boards. Behind this is the actual
wooden frame construction in the form of 200 mm studs and insulated
compartments. On the outside, the construction is clad with gypsum fiberboard,
on the interior side with 18 mm OSB boards and 12.5 mm gypsum fiber boards.
Ceiling structure
Hollow box girders with 280 mm high ribs made of
glulam form the ceilings. Depending on the span, the width of the ribs
varies between 60 and 180 mm. To optimize sound insulation and vibration
vibration behavior, the box girders were filled with 100 mm of lime chippings and covered
and covered with a classic floor structure. On the underside, the ceilings are
with 18 mm thick gypsum fiberboard. The ceilings are usually
on the load-bearing bulkhead walls or on internal columns and beams.
beams. The spruce columns are painted white and remain visible in the apartments.
visible in the apartments.
Transition
Apartment Balcony
The roof consists of an insulated ribbed ceiling
ribbed ceiling with the underside slab as a statically effective surface.
as a structurally effective surface. The elements of the balconies and loggias, as well as those in the
and loggias, and those in the apartments, are connected with an insulated element joint
above the windows. Details: Stuber Holzbau
Fire protection and building physics
Two new wooden staircases were installed for the two new staircases in wood construction. Due to fire protection requirements, these staircases had to be encapsulated and comply with REI 60-RF1. Existing stairwells are of solid construction. The roof also had to 30 minutes of fire resistance because the ventilation system is located on the roof and the pipes ventilation technology is located on it, the pipes cross several fire compartments and the necessary fire fire dampers have to function for 30 minutes.
