The Dexia Tower: An iconic building with a vibrant dark red enamelled steel facade

The full-steel architecture offers a powerful contrast between the parts made of full enamelled steel, with its deep, refined, and vibrant dark red colour, and the glass facades of the tower that are crystalline and entirely transparent.

Detailed information

The Site of the Dexia-BIL administrative centre in Esch-Belval constitutes a major decision and action on two fronts:

- It links together many services previously spread out over about twenty different buildings.
- It is a strong landmark because of its installation in Esch-Belval right on the French border. It therefore represents the first important set-up - the figurehead - which will confirm Dexia's and Luxembourg's faith in the future of this large urban project on an emblematic site, made unique by its singular silhouettes of the old blast furnaces of Arbed.

This project is the cornerstone, located in the north-west corner of the first major square of Esch-Belval called 'Stahlhof'. It initiates the lines that will define the urban landscape of the future Boulevard de Micheville - from the east of the place des Arts to the north-west corner of Stahlhof. The Dexia Tower, which is the flagship of the project as it is a large visual landmark, will contrast with and complement the overlying blast-furnace structures.

This project is organised around a vast atrium - the heart of the project - located in the north-east corner of the square, which will be the distribution space of all these buildings. Future building will gradually complete this services complex, which will be linked with slender glass footbridges. Four levels of infrastructure will complete this project in order to integrate all the logistical areas as well as the parking spaces needed for staff.

The project will thus benefit from a wide panorama over the entire undulating area of Luxembourg and beyond. It could be considered a door from Luxembourg to France.


All the buildings are modular based on 150 cm modules and governed by a 600-cm construction framework. The structure of the rectangular buildings is made of steel. The structure of the Dexia Tower consists of a central core in 6.50-m-wide concrete (bringing together lifts, stairs, and sanitary facilities) and a steel structure.

The steel structure allows wide spans and therefore creates clear spaces inside the building. The Cofrastra® composite floor is supported by variable-inertia beams with spans of 15 metres. These have been designed especially for the project. Their height varies according to a curve (minimum height 42 cm).

The posts are mixed type (steel/concrete) in order to meet the target of fire resistance. These were prefabricated in the factory because of their considerable height (three storeys). The concrete was poured on site and each tube is built into the two ends. The tower consists of 18 levels, two of which are dedicated to technical facilities.


The architectural intention for the facades is expressed by a composition of 'filled and empty' spaces. The project plays on contrast, alternating between the 'filled' facades and the glass facades depending on the orientation. The transparent surfaces are composed of box-frame windows and the opaque surfaces are covered with red enamelled steel panels. These enamelled steel panels have an exceptional dimension of 1.5 metres.

The west-facing facade of the Dexia Tower is composed of a double-skin complex with a naturally ventilated air space.  The planned form of this facade follows a serrated curve. A sun-shade blind is fixed onto the interior skin but is protected by the single glazing of the exterior skin.

Project information

  • Esch-Belval
  • Luxembourg
  • Architect:
    Vasconi Associés Luxembourg, Jean Petit Associated Architect
  • 2005-2006
  • Client:
    DEXIA B.I.L.
  • Engineering Firm:
    Association Simon & Christiansen et Bollinger & Grohmann et Luxplan
  • Photographer:
    Luc Boegly