Front Building of Chliriethalle including the new town hall in Oberglatt, Switzerland, 2011-14
In 2011, Zurich-based architects Frei + Saarinen won the competition to replace a “front building” that was damaged by a fire. The front-building is so called because it is attached to a triple gymnasium that is also used for events such as concerts, exhibitions, carnival, marriages (with up to 1000 guests), etc.
It does not only serve as a new main entrance and the new “face” for the whole complex, but also as a hall for smaller events. In fact, once the authorities of Oberglatt experienced the new spaces (during the construction period), they decided to call the foyer/lobby the new “community hall”. From now on, municipal votes will take place in the new building.
The existing gymnasium / event hall, constructed in the 1970s, was not damaged by the fire, so the question was how to add new to old. The concept of Frei + Saarinen’s winning proposal suggested stretching the roof surface of the gymnasium over the new building. By doing so, old and new are unified by a roof that works like a brace. This was a crucial aim, because old and new should not appear as separate buildings, but as one big freestanding “barn-like” structure, so as to avoid having the addition look like a ridiculous annex.
Additionally, Frei + Saarinen proposed a “Gallery”, an intimate meeting room and a vestibule in the upper level of the existing sports hall to serve the spectators of sporting events. The gallery was not requested in the competition brief and the proposal was risky, as the overall costs of the project were quite limited. Since realization, it has been considered one of the nicest spaces of the complex, with its bench, roof-light and beautiful view of nearby trees.
The entrance area under the generous roof leads to the Lobby, which became the new town hall of Oberglatt. The space measures 200m2 and can be divided by a mobile separation wall. The Lobby connects to the gallery by a ramp. The result is a sequence (lobby-ramp-gallery) that stretches from one facade to the other and makes the spatial experience very generous, particularly in comparison to the relatively small dimensions of other town halls. The black glass cabinets along the ramp and a part of the surrounding walls of the gallery will be used as a display case for trophies, etc
As mentioned above, the simple pitched roof of the old gymnasium is stretched seamlessly over the new addition, but there are multiple folds within the roof in order to generate reasonable room-heights and to create spatial tension – especially over the continuous axis that leads from the lobby to the ramp and gallery. If the separating mobile wall (which is hidden behind a door) is installed, the folded roof is divided into two simple pitched roofs that cover the two separated units.
Among other rooms for delivery and cooking (60m2, allowing for cooking dinner for 200 persons and catering for 1000 people), and a workshop, etc., there is also a club-house– again with an asymmetrical pitched roof with roof-light.
What makes the exterior of the roof special is the varying thickness of its appearance, which makes it look alternately heavy (where it is thick over a low part of the facade) and then light again (where it is thin over a high part of the facade). The inspiration for the varying thickness was calligraphy. In calligraphy, the beauty and tension of the signs are not only achieved by beautiful skillful lines, but also by the varying thickness created by the pens. It might seem like a strange comparison, but the front of the roof is designed to work as a sign for the whole building. Thus, its light silver colour, which contrasts to the black or glazed facade underneath and makes it visible from a great distance.
The facade expresses the varying programs behind it. Public spaces like the gallery or lobby are glazed and the more private spaces, such as the club house have round windows. The reference for the round windows are goal posts – remember that the event-hall is a gymnasium and that the multi-purpose building is surrounded by sports fields. The benefit of the round windows is that the contrast to the glazed walls is maximized (which was the intention), because the closed black parts of the facade appear more continuous than would be the case with rectangular or triangular windows.
The (closed parts of the) facade and roof are a timber construction, because the lightness of the 20m-long roof-elements allowed them to be attached directly to the existing building (without an additional bearing wall). This also allowed for a shorter construction period and was more eco-friendly (less embodied energy with timber).
The steel columns (glazed parts) are covered by “window-frames” inside, creating a contrast between the interior and exterior appearance. Inside, the glazed facade appears as a series of windows, with dimensions that are a happy medium between heavy and light. Outside, the evenness of glass and frames creates a dominating effect.
The new town hall Oberglatt is Frei + Saarinen’s largest building thus far. There are some conceptual similarities to previous buildings such as the conversion/extension of cinema Xenix (Zurich, 2005-07) and the Parish House (Zurich, 207-10). The unifying theme in all of these works is Frei + Saarinen’s interest in the ambiguity between similarity/mimesis and difference/contrast. Only similarity or only contrast leads to simple and clear (but sometimes also boring) results. The challenge is to find the right balance between old and new, similar but simultaneously different. And thereby, to create tension.