Multifunctional office building for city administration
Municipality of Biel
Competition project 2009
The concept for this newbuild administrative building developed from an understanding of the multifunctional nature of urban space, carrying this idea into the building itself. The load-bearing circulation and infrastructure zones are formally derived from bodies of water. They both define the internal space of the building and through their form create dramatic in-between spaces for sitting and meeting.
The proposed design gives the new city hall a unique formal expression, leading it to become a key point of orientation and identity in the urban context.
By skilfully minimising the load-bearing structure, a high level of flexibility of use can be achieved.
The ‚Public Service’ area on the ground floor is designed to be open and inviting. A representative stairwell leads from the reception desk to the different departments on the other floors. The cafeteria activates the public square as well as the adjacent street, Silbergasse, emphasising the dual-sided nature of the building.
The facade is structurally activated and can be used efficiently to spread the linear building loads. The amorphous cores supplement the structural system with two longitudinal beams alongside which the building services are also located. The cores run through all levels of the building and provide the necessary resistance to earthquake forces.
The load-bearing structure is produced using recycled concrete; load-bearing façade elements are prefabricated. The structure is clad in vacuum insulation panels behind a ventilated timber façade. Concrete cores and floors add to the thermal storage capacity of the building and thus improve its ability to regulate internal building climate.
Screenprinted glass louvres provide external shading of internal spaces. As they follow the movement of the sun they allow shading without having to close the building off from its outside environment. Not only does this save energy by reducing the amount of artificial lighting necessary, but it also allows the relationship to the exterior to be retained.
In winter these glass louvres are opened to the sun, allowing optimal use of passive solar energy within the building. Mobile sunshades are located at the individual workspaces, to avoid an unnecessary shading of the whole space when the sun is low.
The skilful combination of structural and prefabricated elements enables construction costs to be minimised; building to the high energy-efficiency standard Minergie P ensures that energy and maintenance costs are also reduced to a minimum.
The shape of the windows is defined by the intention of maximising solar gain close to ceiling level in winter, a crucial aspect for a building of this depth.
The use of structural arches at ground floor acts as part of the efficient structural strategy, while also reducing the amount of opaque façade, as here overshadowing from the surrounding environment reduces the availability of solar gain.
Elmiger Tschuppert architects
Ernst Basler + Partner, Zürich