Diener & Diener - Switzerland
ABB Power Tower
Bruggerstrasse 66 - 72, Baden
2000 - 2002

Almost for a century, the industrial site of the Brown Boveri Cie in Baden, was a forbidden city. Apart from the Bruggerstrasse, which crosses the industrial zone,
the area was not accessible for all those who did not work there. As a consequence of the transition from an industrial to a service economy the location
successively became an industrial wasteland. The workshops which had arisen since the end of the 19th century, could not meet the changing requirements.
With the merger of the companies BBC and Asea, the new Swiss-Swedish ABB was established. The former production company was transformed into an
engineering and high-tech group. The landowners and the city of Baden were equally interested in a restructuring of the area. Together they started with the
development of this attractive area, located near the city centre. In 1993 Diener & Diener architects won a project competition. The structure plan for the
area was definitively approved in 1999. The aim of the masterplan was a new district which combines living and working. The industrial past of the area should
remain perceptible. According to the pragmatic approach, all buildings wich were useful and worth preserving should remain. Buildings without possibility for
conversion were to be replaced by new constructions. The masterplan by
Diener & Diener defines outlines, building heights and volumes but not the usages.

Previously, a residential development had been planned on the grounds of the ABB Power Tower. This was, however, abandoned in the second half of the nineties
due to the changed economic situation. Instead, the
ABB and its subsidiaries were now interested in a second engineering building in addition to the one built by
Theo Hotz on the neighbouring lot. This decision avoided outsourcing company segments, and ABB focused its activities on the traditional headquarter site.

The Power Tower is a six to seven-storey building with 37,000 square meters of gross floor area. The building combines office use and production, and is
used to a larger part by the ABB Utility Automation and to a smaller share by ALSTOM. The functional mixture leads to a building typology that combines
the traditional hall structure of industrial buildings with the comb-shape well known of administrative buildings. The assembly hall for the control systems is
located on the ground floor with a generous ceiling height. Similar to the existing buildings on the opposite side of the street, the interior of the hall
is partially
visible from the Bruggerstrasse
.

The transverse wings of the ensemble are the articulating elements. On the east side these transverse wings correspond to the open spaces between the rear wings
of the building complex by Theo Hotz (also of a comb-shape). In contrast to the neighboring building, the wings are not strictly parallel. The transverse wings vibrate
as a consequence of moderate kinks and twists. Thes moderate bends avoid that employees look directly onto the opposite wall from their offices. The three courtyards,
located above the assembley hall, gain their own character through these moderate kinks. Each of these courts is surrounded on three sides by office floors and opens
towards the east over the pavilion-like test chamber. Each of the transversial tracts has its own entrance giving onto the Bruggerstrasse. A feature which is considered
to be an advantage when rented to different companies. The entrance of the main user ABB is highlighted by the facade offset to the Bruggerstrasse.

The qualities of this architecture are subtleties and differences that are only noticeable at a second glance. The result is an unobtrusive and sensitive building.
A notable feature of this large building is the handling of the facade. At the Bruggerstrasse the stepped facade is broken up by the end faces of the transverse
and connecting tracts. Ribbon windows of different heights and intermediate sills form the rhythm for the connecting wings, which are executed in exposed concrete.
Behind these facades are different usages: offices, assembly hall, cafe, restaurant and Atrium (surrounded by galleries). The elevations of the transverse wings is
designed fundamentally different. It consists almost entirely of glass. The massive wall is clad with different layers: insulation, brass colored anodized expanded
metal and greenish molded glass. The high-stretched rectangular glass plates with the height of a storey alternate with the actual windows. At the end faces this fašade
disguises the actual wall structure. Sometimes the windows are provided with clear glass panes, but somethimes the glass skin ignores the building structure behind it.
Depending on the weather and the sunlight, the apearance of the sophisticated facade changes. The glass shimmers multifaceted in different colors.