Perhaps the most crucial element for the new building of the University of Applied Sciences Sihlhof is the Zurich Main Station. The railway station was
not only determinant for the chosen location, but also commands an intensive use of land. Consequently, the building owners decided to accomodate not only
the College of Business and Administration, but also the University of Education in this building. On the one hand this is to be regarded as a response to
the preferred site and the associated economic conditions, on the other hand the pressure on the small parcel is even further increased. The architects
Giuliani Hönger, who won the 1999 competition, answer to this challenging conditions with a complex building structure. They start with the maximum
building volume allowed by the Zurich building code, so that the can accomodate a maximum large spatial program. From this determined volume of great depth,
the architects cut out inner cavity which allows daylight to enter into the structure, and the same time organizes the different usages. The classrooms are
designed as individual cells and are embraced by the corridors, so that they are determined by an inner and an outer contour. The high urban pressure results
in a spatial compression and intense relations between all parts, between the school and the surrounding buildings, but also between the interiors of the different usages.

One of the great challanges in this design, was the integration of the large volume into the heterogeneous scale of the urban environment. In order to achieve
an adequte integration, the body of the building is stepped back in two-story stages. This volumetric manipulation results in terraces which are used for recreation.
These terraces are regarded as a school yard which is structured and integrated within the buiding. All opaque surfaces of the building envelope are made of
prefabricated artificial stone elements. The horizontal and vertical elements are assembled in a tectonically way emphasizing the volumetry of the building.
All exterior surfaces of the building are covered with these large artificial stone elements, since these elements are also also used to cover the receding terraces,
all horizontal and vertical edges of the building are equally treated. Consequently the roof edges are made in the same material and emphasize the monolithic
quality of the structure. The beige-yellow color of the artificial stone originates from the Jura limestone and was emphasized by the grinding of the elements. This color
refers to the predominant hues of surrounding buildings. The facade is equally claimed by the classrooms, resulting in a regular external appearance. While the interior
of the building expresses the two different schools, they are not recognizable on the exterior, resulting in an uniformly and quiet integration into the urban context.
The disposition of the façade elements is designed by the architects in a refined layout allowing multiple readability. At first glance the façade appears as
a regular structure, in which the pillars, spandrel panels as well as the smaller and larger windows alternate and thereby weave one into another. Only a more analyzing
contemplation reveals a disturbing irregularity. The façade pillars are indeed regularly on the building corners, defining the precise edges. But, however, even the next
following pillars are slightly shifted to each other. On all façades the shift accentuates towards the middle of the facade. By this measure the building is set in
a calm vibration, which emphasizes both its integration into the existing edification as well as its independent position as a public building. At the same time,
these slight shifts allow a pragmatic modulation of the room sizes and its adaptation to the required program.

The inner hall of the Sihlhof university building develops upwards over the entire height of the seven classroom storeys. This inner hall contains both of
the interior common rooms of the two integrated schools. Both of these common spaces can be interpreted as a single spatial form or as part of a coherent court figure.
The inner spatial figure actually consists of two stacked halls, which are slightly shifted against each other. The two halls come into contact at one point and
become interconnected. Through this measure, each school receives its own spatial focus within a common central interior.
This inner hall is the centrepiece of the whole structure, rich in relationships and highly characteristic, creating an own identity for the university building.
As it was already mentioned, this interior hall allows daylight to enter the interior of the building, in turn this allows the entire façade to be used for the primary use.
This introverted, constantly changing domestic space creates a lot of internal relationships and specific places characterized by various neighborhoods and perspectives.
The staircases are located in separate, shaft-like cores adjacent to the halls. As a consequence of this design decision, the hall gains independence,
like an outonomous subject, and allows the visual relations. Especially the lack of stairs enhances the abstract quality of the hall and emphasizes the impression
of a space without scale. This impression is even exacerbated by the changing arrangement of the corridors in open balconies and closed galleries.
The natural stone flooring in the inner corridors and circulation spaces translates the material atmosphere of the façade construction to the inside, however,
in refined form and color. These floors are like guiding routes which penetrate deep into the building mass, and at times are perceived as part of the inner hall.
The walls of the circulation spaces are made of exposed concrete. The materiality and the steady continuum of this circulation spaces, give them the atmosphere
of a public space. The classrooms are contrasting with this moving three-dimensional shape in robust materials. They are designed as introverted chambers full of light,
bright and resting in themself covered with textiles.

The spatial concept of this building required a inovative structural logic. While conventional static systems assume that the longitudinal and transverse walls of a structure
are superimposed, here the walls are constructed as slabs, which can be stacked crosswise according to certain rules. The longitudinal walls can slide on
the transverse walls towards the inside. The structural system is developed from the idea that a layer of surrounding classroums is accompanying the façades.