Building

Planning requirements specified an automated storage facility and an administrative wing; the desire was to unite both uses in one building. Requirements also included the option to expand the high-bay storage facility in a modular manner without interrupting ongoing operations. Additionally wishes were an energy-efficient building; a low-maintenance façade and an extendable, sustainable construction design. The positioning of the administrative wing, which also includes technical services, now anchors the building to its surroundings, with the storage facility appended to it. The administrative wing’s elongated position has the advantage of a wide façade which provides large amounts of natural light for the workspaces. The use of modular concrete elements facilitated efficient construction of the storage facility. These double-skin, thin-wall concrete elements are lightweight, can be prefabricated off site and quickly installed. They were filled with liquid concrete on site and, in combination with reinforcements which had already been installed into the elements, resemble monolithic 36-cm thick steel reinforced concrete walls. Steel trussed girders span the approximately 75 m long and 20 m wide structure without supports.

Should the building be extended, then its rear curtain-wall façade can be removed; an additional module constructed and the façade then reinstalled. The concrete elements making up the old rear wall remain in place as they have pre-marked openings to allow expansion of the horizontal conveyor belt system. The entire building is hermetically sealed and has an inert atmosphere. The reduced oxygen content in the atmosphere prevents the starting and spreading of fires.

• The building is earthquake-proofed.
• It is secured by alarm systems for fire and burglary and has a CCTV system.
• The perimeter of the premises is secured with a 2 m-high wire-mesh fence and access is controlled with a sliding gate.

The building envelope is clad with a rear-ventilated metal curtain-wall façade constructed from weather-proof construction steel (Corten steel). A copper-, chrome- and, where applicable, nickel-based alloy forms a barrier layer which protects the steel from further corrosion. Just as with normal steel, exposure to the elements and corresponding damp, rain and dryness causes the Corten steel to rust. Thanks to the alloy elements a complex, adherent, non-permeable barrier layer is, however, formed between the base material (steel) and the existing layer of corrosion. This process takes around one to two years. During this period, the surface has patchy areas of rust, following which the layer of rust is evenly spread across the entire surface and the corrosion process stops. Although the sheets feel rough, rust particles adhere to them.

The architects placed value on the analogy of the descriptive terms ‘book storage = knowledge storage’ and ‘building extension = knowledge extension’. The industry-type construction should also reflect the building’s rural industrial character. The colour of the raw steel sheets should echo the colour pallet of the surrounding tiled roofs and farmland. The steel’s durability was another reason why it was chosen as was the fact that it simultaneously makes the aging process visible. The chamfered sheets are folded, which, on the one hand, makes the large structure appear smaller, while, on the other, this also allegorises plans for its extension by referencing an accordion. The strong refraction of light around the folds creates a richly contrasting interplay of light and shadow, giving the building, which can be seen even from a distance, an unmistakeable identity.

In addition to this, the folds in the steel also serve to stiffen them, benefitting the building’s statics and saving material. A perforated strip inserted into the upper sheets subtly draws attention to the edge of the roof as well as serving to ventilate the façade. The perforations are also repeated in the signage, which takes the form of green sheeting in this area. The plinth is comprised of fluted concrete elements which channel with rainwater away from the building, thus preventing rust in the water from causing uncontrolled discolouration.