On May 13th 2008, the buidling of the architectural departement in the Technical University of Delft burned.Our project of reconstruction proposes to create a ghost of the old building, by extruding the exact footprint of the old one.In order to create a necessary volume for the requested program, the form is duplicated, rotated at 90° and placed on its base.The grand lobby is the key space which links the two bodies of the building. It developes through two levels, ground floor and 1st floor. The lower part is directly connected to the entry and distributes the larger spaces of the program : administration offices, library, restaurant and exhibition spaces, while the upper part is connected to the horizontal space joining the four towers.The south-east side facade is protected from the direct sun by a series of glass screens. Their changing position makes possible optimal protection while keeping the view towards the landscape.