A digital cluster located in a secure area

Fredy Décima company - 18 months


  • Date of building the gunpowder magazine : 1682
  • Net floor area gunpowder magazine: 100 m²
  • Project duration: 18 months (after obtaining building permission)
  • Date commissioned: May2014

A concept tailored to the context
Within the context of the overall citadel reconversion project, Arras Urban Community launched a call for projects concerning the powder magazine and the adjacent building.
And that is how the citadel digital cluster came to be: Powder will now be replaced by the digital data of the 21st century. The adjacent digital complex is home to small companies specialised in information technologies and communication, e-commerce and networks. Twenty-one offices covering a total area of 730m² and two meeting rooms are at their disposal for a low rent.

Ingenious implementation
Frédy Décima, owner of a company based in Arras for several generations bought the buildings and paid for all the fitting out work himself. Arras Urban Community, won over by the proposal, accepted it on the proviso that an armoured glass vestibule and a glass floor were put in place in the gunpowder magazine making it possible to fully appreciate this historic building and see inside the datacenter. A geothermal system has been installed to cool the servers. Water is drawn from a depth of 40 metres at a temperature of 11°C.
A heat pump system also makes it possible to benefit from the heated water to supply the digital complex before it returns to the water table.

Finance plan

Overall investment; 2M€ exclusive of VAT


Positive aspects

The digital cluster strengthens the reconversion process initiated by Arras Urban Community and gives substance to the project designed to turn the citadel into a genuine area of the town.
The investment cost (digital complex and datacenter) is estimated at 30 % higher than a new build. The entrepreneur’s initiative is driven by his attachment to the local area and by the historic nature of the location. However, the fact that the citadel is part of the Vauban fortifications included in the World Heritage list has not impacted his approach and the architectural features of the gunpowder magazine do not represent any real advantage for this new usage, with the exception of making the datacenter a significant sales argument. Putting in place the geothermal cooling system required conducting feasibility studies, but the return on investment will be rapid (three years) and enable energy costs to be divided by three.