At the start of the 1990s the Court began to plan an ambitious construction project, prompted by both the need to vacate the Palais in due course because of the presence of asbestos and the need to prepare for the forthcoming major enlargement of the Communities. The Luxembourg authorities agreed to act as project contractor within the framework of an agreement, endorsed by the budgetary authority of the Union, under the terms of which the Court undertook to take over the buildings under a lease-purchase system. 
The Luxembourg authorities asked the architect Dominique Perrault to draw up a plan taking into account not only the needs of the Court but also the spirit in which the Court wanted the project to be carried out.

For the Court, the project was not about simply constructing a new extension but about reviewing the entire complex of Court buildings so as to design a new Palais, taking into account the need:

• to be able to adapt to cope with an increase in the number of Member States, and consequently Judges, Advocates General and staff, and even the addition of new courts, without disrupting the overall scheme of the architecture;
• to separate clearly, in particular for the purpose of making optimum security arrangements, the public areas essential to any judicial proceedings and the "private" areas consisting of the Members' chambers and the offices of the services of the Court;
• to give the new building the same iconic value as the Palais inaugurated in 1973;

The architectural design submitted by Dominique Perrault perfectly fulfilled these requirements. It comprises:

• a two-storey peristyle building called the "Anneau" (literally, "Ring" in English) in spite of its rectangular form, because it encircles the original Palais. The Anneau is designed to be a non-public area reserved for the work of the Judges and Advocates General along with their staff, which can accommodate up to 40 Members and their chambers;
• the original Palais, preserved but remodelled. The entire available space is now given over to courtrooms, in other words, to the public face of justice. These rooms are equipped with appropriate technology to comply with the Court's multilingual requirements and are sufficiently large to cope with the increase in judicial proceedings;
• two Towers to be joined, eventually, by a third tower, the construction of which will not jar with the overall scheme of the architectural project;
• a Gallery, which gives an architectural and functional unity to the new complex by linking all the new and existing buildings.