The data centre for Rabobank in Boxtel is a computation centre comprising 2 storeys, each measuring 4,000 m2 gross floor area (GFA) and a height totalling 12 metres. The computation centre is flanked by 4 energy buildings with 3 storeys, 7,400 square metres in all, and a height of 18 metres. In addition, a 4-storey office building is being constructed with a GFA of 4,200 m2.
The architecture of the data centre is subservient to technology. The wide concrete plinth serves as collision protection. This border is thematically repeated on roof level and in the intermediate facade borders, giving the building an indication of size and scale. In between these horizontal elements, the facade contains pronounced pointed profiles, applied vertically, and a rather random, playful array of windows, grills and lead-throughs. Up until the actual construction phase, modifications as a result of changing technological specifications are included in the facade openings. This theme is continued in the architecture of the offices. The facade borders actually follow the lines of the floors and the facade in-between the borders contains a storey-high curtain wall with transparent and translucent panelling; again, in a random layout. The pointed aluminium profiles provide essential depth, allowing for example the exterior sunblinds to be neatly concealed. The concrete plinth attractively yet modestly accentuates the main entrance of the building.
This major complex is being built near the edge of Boxtel, on an industrial zone that was initially intended for small-scale businesses. In order to have the data centre fit in with its environment, the data centre and the energy buildings were completely covered with natural roofing. From the outside, all you see is a green slope rising up from the landscape, bordering the ecological zone that separates the industrial area from the surrounding farmland and the village of Lennisheuvel.
This concept fits in well with the desired green image of the municipality of Boxtel, as well as the philosophy of the Rabobank.
At date of delivery, the data centre is the greenest data centre in the world. It has an energy factor of 1.26, at full capacity of 2500 W/m2. Conventional data centres have an energy factor of between 1.8 and 2.2. Temperature is controlled by means of a heat/cold storage in the ground. The data centre is laid out with an extremely efficiently operating cooling concept of cold streets along which the ICT equipment is arranged. The cold water for this is produced by means of water-cooled cooling towers, which, in turn, are optimally fed by the natural cold present. Whatever the exterior conditions, the cooling towers are regulated in such a way as to operate as efficiently as possible. Water cooling is the most efficient system. Rain water is collected to be reused for the cooling towers. The necessary electricity is purchased on the basis of wind energy. Most measures used to achieve this sustainability are invisible to the public – which is one of the reasons why Rabobank welcomed the natural roofing to demonstrate the green image of this, the greenest, data centre in Europe.
Naturally, the office building benefits from the presence of the data centre where energy and sustainability are concerned. Excess heat from the data centre is used for the heating of the offices. Cooling is also obtained from the data centre. And there’s more. In the office building, other factors are being introduced that will contribute to energy conservation and the sustainability of the building. One of these factors is Compact Construction: the shape of the building – a rounded-off triangle with an atrium – ensures an outer-shell surface that is 23% smaller than a traditional office building’s surface. This concept, with open office floors that are visually connected by means of a large atrium, while allowing extra daylight as well, fits in perfectly with the new ‘unplugged’ working philosophy of Rabobank. This new working method generates an office floor area of 17 m2 per FTU instead of the traditional 25 m2 per FTU.
Optimum daylight admission in buildings, in combination with HF fittings provided with a daylight switch and presence detection, will save considerably in electricity. Moreover, it will ensure a working environment where people feel comfortable, perform better, and show less absenteeism. That is why the outer façade is designed as one made completely of glass. To avoid too much heat radiation, 60% translucent glass panels with a high insulating value were opted for and 40% fully transparent glass, in combination with exterior sunblinds on the southern, eastern and western façades. Daylight enters the atrium from above, ensuring a natural daylight feeling even in the lowermost workplaces.