The Louise Weiss building (IPE 4) (named after the MEP of the same name) is located in the Wacken district of Strasbourg, south of Schiltigheim, between the 1920s worker's suburban colony (Cité ouvrière) Cité Ungemach and the 1950s buildings of the Strasbourg fair, some of which had to be torn down to make way for the Immeuble du Parlement européen 4, its technical name. Built at a cost of 3.1 billion French francs (470 million euros) at the intersection of the Ill and the Marne-Rhine Canal, it houses the hemicycle for plenary sessions, the largest of any European institution (750 seats – expanded to 785 – for MEPs and 680 for visitors), 18 other assembly rooms as well as a total of 1133 parliamentary offices. Through a covered footbridge over the Ill, the Louise Weiss communicates with the Winston Churchill and Salvador de Madariaga buildings. With its surface of 220,000m² and its distinctive 60m tower, it is one of the biggest and most visible buildings of Strasbourg. The Louise Weiss was designed by the Paris-based team of architects Architecture-Studio. The architects were inspired by Roman amphitheatres. After the project was approved at an international contest in 1991, work, commissioned by the Société d'Aménagement et d'Équipement de la Région de Strasbourg on behalf of the Urban Community of Strasbourg, started in May 1995, with up to twelve tower cranes at the time on what was one of the biggest building sites of the decade in Europe. The inauguration of the building took place on 14 December 1999 by French President Jacques Chirac and Parliament President Nicole Fontaine. In internal EP documents, the building is referred to as "LOW".
The voluntarily unfinished aspect of the 60m high tower carries heavy symbolism, as it is alleged to have been oriented eastwards, i.e. towards eastern Europe, of which by the time of the completion of the building no country had yet joined the EU. However, the open side of the tower actually faces west. Urban legends and Internet memes have long alleged that its design consciously mirrors the Tower of Babel as painted by Bruegel (the Vienna version), and although unfounded, the rumour has entered mainstream media through Glenn Beck. On 14 January 2009, the European Parliament decided to bestow the name of the recently deceased, distinguished MEP for Poland, Bronisław Geremek, to the courtyard inside the tower. The "Bronisław Geremek Agora" (French: Agora Bronisław Geremek) was officially inaugurated on 21 April 2009.
Members sit in a hemicycle according to their political groups arranged mainly from left to right, although with the non-attached members towards the back and right of the chamber. All desks are equipped with microphones, headphones for interpretation and electronic voting equipment. The leaders of the groups sit on the front benches at the centre, and in the very centre is a podium for guest speakers. The remaining segment of the circular chamber is primarily composed of the raised area where the President and staff sit. Behind them there is an EU flag attached to the wall with national flags in rows each side of it. Interpretation booths are located behind them and along the sides of the chamber, while public galleries are located above the chamber around the entire perimeter. Further benches are provided between the sides of the raised area and the MEPs; these are taken up by the Council on the far left and the Commission on the far right. The chamber as a whole is of a modern design, with the walls entirely composed of lights with large blue chairs for MEPs.