Herzog & de Meuron have completed an extension to a convention centre in Basel, using sheets of brushed aluminium that transform into beautifully woven façades that look like they can breathe. The texture and visual interest created by the architects’ innovative use of materials also help to weave a very large building into its surrounding urban fabric.

Brushed aluminium is a fantastic cladding material for a number of reasons. It is weather resistant and lightweight and it’s available in a diversity of brilliant colours to name just a few. So it is no surprise that the seven expansive façades that make up Herzog & de Meuron’s Messe hall in Basel (Switzerland) are clad with aluminium. But, there is a material twist here – the 15,000 brushed aluminium panels that make up the façade were individually cut and bent in response to a parametric script that translates two-dimensional elevation drawings into a three-dimensional reality. The resulting building envelope appears less like a gleaming building box and more like an artfully woven, metal basket.

Designing the exterior façades of a convention centre is a notoriously difficult design challenge. The challenge results in part because of spatial and functional requirements which specify that civic exhibition halls should be rectangular in shape, with very wide floor spans and ceilings often over 10 m high – along with an absence of windows or other architectural articulations. The ultimate intention is to provide large scale, interior event spaces with maximum versatility and flexibility. Unfortunately, these requirements often translate into monolithic facades that are difficult to integrate into the context. It is therefore understandable why the term ‘dumb box’ characterises the architecture of many convention centres.

But with a brief to design three exhibition halls and supporting amenities as part of a new convention centre in Basel, Herzog & de Meuron responded with a series of stacked boxes that meet the standard brief of an exhibition hall (i.e. wide, windowless, rectangular and high spaces) but are anything but dumb and ordinary, due to their innovative use of materials.

The ground floor of the convention centre, with an area of approximately 10,000 m², has a direct relationship to the adjacent street and public space. Large areas of glazing achieve a spatial and visual transparency that connects the exhibition halls along with their associated shops, bars and restaurants to the outside flow of pedestrian traffic. Two new exhibition halls dressed in the woven aluminium panels are stacked on top of the ground floor. These two upper floors are then offset from each other in order to create two distinct volumes and avoid a ‘big-box’ effect. Each of the volumes projects over the surrounding streets to different degrees, creating a variety urban conditions beneath the building. For visitors, neighbours and pedestrians passing by, dynamic massing and innovative use of materials result in a  range of spectacular street-scapes and views that are hardly monolithic or ‘big-box’ in their nature.

This project is a great example of how designers can transform an ‘ordinary’ material – such as brushed aluminium – into something special. In this large convention centre in Basel, aluminium twists and turns to transform into a material that is more like a malleable, woven basket than a standard sheet of metal cladding. The result being a convention centre that really feels more ‘woven in’ to its surroundings.

_{More info on the project here.}

_{Image credits: Iwan Baan; Herzog & de Meuron; Arch-photo.}