Enigmatic Curtain: Factory Building by SANAA

A curtain façade made of invisibly suspended wavy acrylic glass elements envelopes the entire volume of the building, imparting it with an almost immaterial character. The exterior walls, roof and supporting structure remain completely hidden behind it. Absolutely nothing indicates the highly complex production processes taking place inside.

Architects: Kazuyo Sejima + Ryue Nishizawa / SANAA, Tokyo
Location: Vitra Campus, Charles-Eames-Str. 2, D-79576 Weil am Rhein

Paper-thin, yet crystalline like Carrara marble: a white curtain, 11 metres high and over 500 metres long, encloses the 20,000 m² large factory building on the Vitra Campus. Completed back in 2009, the client Rolf Fehlbaum had to wait patiently for a total of three years for the icing on the cake: the façade of this “factory of the future”. The persistence of Kazuyo Sejima and Ryue Nishizawa was however well worth it in the end: SANAA has come up with a reinvention of industrial construction design.

The corrugated skin does in fact resemble a delicate layer of icing covering a massive white cake, taking up the colour hues of the surroundings, reflecting highlights or remaining virtually invisible behind white cherry blossoms against a leaden sky. The most subtle play of light can be observed along the upper edge of the roof structure: even diffuse sunlight penetrates the only 6-millimetre-thick acrylic glass panels, shimmering white against dark clouds or contrasting the pale sunlight unable to penetrate the fog in an elegant matt grey.

Rolf Fehlbaum wanted to break away from the outdated image of noisy and often dirty factory halls – the light and almost weightless building is an architectural expression of the new atmosphere of production environments. His parents and founders of the company already had very close contacts with architects and designers, particularly with Charles and Ray Eames. When Rolf Fehlbaum took over Vitra, he commissioned the architect Nicholas Grimshaw to design a new factory building to replace the production facility damaged by fire in 1981, as well as to reposition the whole brand.

The concept of having the entire company premises designed by one architect was turned upside down by his acquaintance with Frank Gehry. With Gehry’s Vitra Design Museum, a former Fire Station by Zaha Hadid, Tadao Ando's Conference Pavilion, and another factory building by Alvaro Siza, Fehlbaum has represented a selection of the world's most renowned architects on his company grounds.

A concept for a new venue suitable for presentation of the Vitra Home Collection as well as a new production facility for Vitrashop – a shop fitting company within the Vitra Group – was developed in 2005. Fehlbaum recollects that there was no question about which architects were to be commissioned for these projects: Herzog & de Meuron of local renown, and SANAA (who were less known then) from abroad. What remained unclear for quite a long time however, was which office should build which project.

The issue was resolved and since 2009, home builders and owners, as well as architecture enthusiasts have been flocking to  VitraHaus by Herzog & de Meuron. The factory building was also already completed by then: only the outer envelope was missing.

SANAA's factory building for the affiliated company Vitrashop is intentionally designed to be a kind of antithesis to the redbrick construction by Alvaro Siza – lightness instead of heaviness, immateriality rather than surface texture, motion instead of constancy. This objective was consistently realised by SANAA; half-hearted detail solutions were simply unacceptable.

"You never win against Sejima," says Fehlbaum at a press conference with a big grin on his face. "She can be pretty stubborn!" Three further years of intensive development work finally resulted in the realisation of a glued façade structure, allowing for a calculated expansion of up to 7 centimetres of the individual 11-metre-high and 1.80-metre-wide panels in case of temperature fluctuations, without any bulging effects.

Kazuyo Sejima and Ryue Nishizawa studied the land, the hilly landscape and the many trucks constantly on the move heading to and from the docking bays. A diagrammatic representation of this movement pattern resulted in an almost circular ground plan for the hall.

Already in their museum in Kanazawa, they would have preferred a slightly softer organic geometry to the perfectly circular form. Being more inexperienced then and for pragmatic reasons, they opted for a circle. In the factory building they were now however able to realise this idea, because the building is much larger and the curves are therefore also broader. The general aim was to give the harsh geometry of the Vitra Campus a soft touch like a fluttering curtain. That's why the ground plan isn't perfectly circular, and the "drapery" is irregular.

Visitors going on a tour of the campus are told that the elaborate façade was also an important factor for making the building acceptable to the residents. The first reaction to "By the way, we are going to build a factory hall right outside your living room" is always "No way!". The ability to communicate that the residents will be looking onto an important work of art in future, on the other hand, fills them with pride.

After the three-year waiting period, the people living in the neighbourhood have actually grown to love the building. In foggy weather, the not exactly small building with a footprint of 20,000 m² disappears behind the white cherry blossoms. The dark windows appear to float in the air between the trees on such days. Taking these photographs on just such a day, a neighbour pointed out that a much more suitable day would have been one with sunshine or perhaps towards the evening – the irregular undulations of the envelope come out really magnificently then.

Project data Client: Vitra Verwaltungs GmbH
Architectural execution: Mayer Bährle Freie Architekten BDA, Lörrach / nkbak, Frankfurt

Preliminary study: 2006
Completion: December 2012
Structural planning: Bollinger und Grohmann GmbH, Frankfurt / SAPS – Sasaki and Partners, Tokyo
Façade: STRABAG AG, Vienna
Façade panels: k-tec GmbH, Radstadt
Façade structure: imagine structure GmbH, Frankfurt

Site area: 50,000 m²
Building footprint: 20,455 m²
Diameters: 156 x 159 m
Building volume: 206,600 m³
Building area: 20,455 m²
Façade area: 5,740 m²