Page 144 - AIT0416_E-Paper

BÜRO UND VERWALTUNG • OFFICE BUILDINGS INNERE WERTE • INNER VALUES

A s every year, in autumn 2013 we took time out from our office routine. Sitting on the
Campo San Barnaba in Venice, we decided that, after almost ten years in rented pre-
mises, the time had now finally come to design our own office property. While abroad,
immediately a building came to mind which we could see from the office every day: a
tower fallen into oblivion and yet still present in the cityscape which in fact had been up
for sale for some time. With the purchase of the old railway water tower in the Heidelberg
Bahnstadt in 2014, we took the opportunity and, after a construction period of one year,
in autumn 2015 the Tankturm became our new location. The tower had been constructed
on Eppelheimer Strasse in 1927 as part of the Heidelberg railway depot, a signal box for
more than forty locomotives with coaling- and sanding stations as well as a slag pit. As
part of the site, “our” water tower served for filling the steam locomotives and for sup-
plying the depot. It consists of a central, 30 metre high, square tower building with a tent
roof and two two-storey annexes in the east and the west. The building was constructed
on top of a concrete base reaching up to the parapet of the first row of windows. The
exterior walls above it consist of open masonry for which hard-fired bricks were used.
Halfway up the tower, on all four sides clocks had originally been mounted. The water
container on the inside was built above a self-supporting, dome-shaped supporting plate
and had a capacity of 333 cubic metres with a water-level height of 27 m. Its walls were
made of concrete with a thickness of 30 centimetres. The rooms in the side wings served
as workshops as well as workrooms and lounges. Next to them were rooms for a rectifier
station for charging the batteries for the electric train lighting and for a gas- as well as an
air compressor. In the basement was a transformer station. Since the post-war years, the
railway used the rooms above all for training and teaching fitters and power electricians.
Interaction of art and architecture

After we had bought the tower from Bahnstadtgesellschaft EGH in 2014, the building was
renovated and converted from November 2014 until November 2015. In the east wing are
today our offices, while the west wing was rented by the Heidelberg association of con-
temporary music Klangforum for its office as well as its rehearsal rooms. Under the name
Im Ostflügel entstanden die über alle Geschosse hinweg ... • In the east wing, the architects’ offices .... of Tankturm, the premises are also available for cultural activities, conferences and
events. The Tankturm is furthermore also a platform and a stage for modern forms of
... miteinander verbundenen Büroräume der Architekten. • ... connected across all the levels were designed.
expression regarding fine arts, literature, music, theatre and dance as well as cross-over-
events. Cautious interventions characterized the listed-building suitable dealing with the
building. The striking shape and the exposed masonry of the outer envelope remained
untouched as did the existing ashlar base as well as the windowsills. The roof constructi-
on was also preserved as a visible construction and given rafter insulation as well as a
new, listed-building suitable cladding. Insulation between the rafters was applied to the
windowsills. At the intersection of the two constructions, a narrow, continuous band of
windows thus resulted for illuminating the roof top. It goes without saying that the water
tank was also preserved as structuring, historic testimony. To illuminate the interior and
spatially enlarge it, the tank was partly sawn open. Access is from below via a centrally
positioned spiral staircase of steel. A fireplace turns the tank into an atmospheric lounge.
An elevator ensures barrier-free access. On the lower tower storeys, the steel stairs grow
into a kind of spatial sculpture which links the different levels and, with its industrial
material, adapts to the visible concrete construction.

Between the poles of tradition and innovation

Der westliche Anbau beherbergt Veranstaltungsräume. • The event rooms are in the west annex.
In the office areas in the east wing, all the storeys are linked by open spaces so that the
top floor rests like a raft on the old wooden beams. This vertical opening was foregone
in the seminary rooms in the west part. Glass walls and light-weight curtains, however,
produce a high horizontal permeability. The furniture in the office areas is designed to be
clear and minimalist. White suspended shelves of edged steel sheet serves as a storage
space and a room partition. It can clearly be noticed as a newly added element compa-
red with the existing shell. New box-type windows added from the inside now allow a
view of the historic windows and reveals. Towards the outside, the interventions are only
noticeable from the emergency balconies inserted into the tower and a large showcase
window into the event hall on the ground floor. Thus the modern dealing with the austere
brick aesthetics transports the industrial monument into the 21st century, as an authentic
cultural site, puts it into the focus of the public. With the Tankturm, an open space was
created where culture and industry are to meet on a common ground. The stringency
with which the historic architecture was complemented and enriched with new ele-
ments, is in the process to develop a radiance which, while the building it is used every
day, enters the consciousness and opens up room for new synergies.

144 • AIT 4.2016