Headquarters of the National Highway Maintenance Department

The headquarters of the national highway maintenance department has been designed as part of an extensive town-planning concept, as a complex which comprises 10 buildings. Located in a mixed-use industrial zone approximately 10 km from the city of Luxembourg, the new facilities for the central workshops of the Luxembourg highways authority occupy a plot some 7 ha in size. These facilities comprise the workshops and garages; the central salt stores with their silos; a materials-testing laboratory; and the offices and amenities for the various services. A number of buildings still operating on the site will be converted to fit in with the site as a whole. The scale of the project, its heterogeneous town-planning setting and the need to carry out the project in consecutive stages so operations could continue on the site all required meticulous planning. A simple structure that could be duplicated and extended met both the needs of this complex programme and the functional requirements of the activities involved, while respecting the town-planning constraints. The linear alignment of the garages, parallel to the railway line and highway that adjoin the site, ensured optimal utilisation of the surface area both in terms of the site itself and the way operations were organised. This concept gives the building complex a clearly defined external boundary: protected from the outside, the service operations can be conducted within the site without interference. Moreover, the large garage buildings provide acoustic and visual screening for the immediate surroundings, zoned for housing. Two broad traffic zones are located within the plot, accessible to all service vehicles, including trucks with large turning circles. Along the perimetre of the site, the buildings are closed and clad with a uniform metallic structure in extruded aluminium reminiscent of motorway crash barriers. The garages and workshops with their recessed glass gateways create optimal lighting levels within the halls. The regular cross-section of the garages reflects the width of the vehicles housed there. Offices for the workshop management, the meeting rooms and the canteen have been sited in such a way as to be directly accessible from the entry points to the site. Peripheral parking for staff and visitors avoids hindrance to the works traffic inside. Further into the site are the buildings with more specific functions. Their individual functional and structural constraints mean that they have, as a direct result of functional imperatives, assumed quite different architectural forms from the metallic appearance of the garages and workshops. One of these core buildings is the new salt store containing the central salt stocks, silos and loading hoppers. This building was completed in 2005, as were the workshops and garages. It comprises two hangars, each with a capacity of 3500 tonnes, together with two 200-tonne silos. The building s function as a salt depot required the use of carefully selected materials, wood and stainless steel, not easily damaged by salt. The semitransparent polycarbonate sheeting used for the cladding of the external facade reveals the underlying wood structure, providing an interplay with the exterior through the interaction between light and reflections.