Diener & Diener - Switzerland
City Museum Aarau
Schlossplatz 23, Aarau

2006 - 2015

Since 1939, the historic walls of the Aarau castle are housing the local town museum. The historic building is a mighty tower of relatively large boulders.
This tower existed already before the founding of the city of Aarau in the 13th century. This also explains its location outside the town walls
to the east of the historic centre. The building therefore provides the perfect setting for the mediation and illustration of the history of the city.
However, the historic building was no longer up to date with the contemporary requirements of a museum. In particular there was missed
a large room for temporary exhibitions, which could also address contemporary issues. The use of the historic rooms for a flexible exhibition design
was quite restricted, and large areas of the available spaces are lasting occupied by the permanent collection. In order to adapt the museum
to the current requirements, a competition was launched. In the year 2007 the architectural office
Diener & Diener won the first prize in cooperation
with Martin Steinmann. Two years later, the expansion of the city museum was approved in a popular vote. In April 2015, the extension as well as
the renovated tower were inaugurated.

The architects did not plan the additional volume within the given competition perimeter (east of the castle tower), but to the west of the tower.
In their explanatory report to the competition, the architects emphasized that the location was chosen out of respect for the historically grown
urban structure. With this choice of the building site it should be avoided that the castle enters a historically false relationship to the buildings
of the so-called Laurenzenvorstadt. This important decision perseved one of the few places from which the topography of Aarau is experienced.
This urban resetting results in a new composed castle square which features a spatially concise definition.

The choosen building site allowed a serious connection between old and new, especially since the terrain profile at this location allowed to design
the addition as an annex to the historic tower. The advantages of an annex instead of an addition docked to the historic building by means of a bridge
or other auxiliary structures, becomes obvious in the interior organisation of the project. A generous stairwell with elevator serves as a joint and gives
access to both buildings. The complexity of this stairwell becomes obvious in the sectional drawings, the show the different number of floors and different
floor heights. The building consists of four stacked rooms with approximately the same floor plan. At street level there is a large foyer, in the basement is
located a photo and movie room, on the upper floor is the exhibition hall and on the roof one encounters the administration which appears as a glazed top.
The exterior walls of the exhibition space on the upper floor are completely closed, and the room receives partially light from above. The top floor,
where the offices are organized, is realized as a lightweight construction, which differs from otherwise solid building. This lightweight construction
is experienced as an attic, which refers to the adjacent buildings.

A special feature of the extension is the design of the facade with figurative ornamentation. When it was proved that
a 120-year-old sequoia tree had to be cut
for the expansion of the museum, the architects decided to call in the sculptor Josef Felix Müller. He was entrusted with the design of the facade, and all what was
left over from the tree was harnessed for the architecture. The trunk of the mammoth tree was sawn into planks, and Müller made them into image panels,
measuring 200 cm x 95 cm. These reliefs were used as templates for matrices from which concrete elements were cast for the facade. Unlike in historical buildings,
the figures were not specifically applied to key points, but were spread all over the entire main façade, so that it is actually captured by the figures. Contrary to the logic
of prefabrication, in this building each of the 134 elements with its own figure is unique. These abstract figures are considered to represent the different characters
of the Swiss society, and thus also refer to the democratic tradition.