Atelier LWD was an architecture studio led by Guy Lagneau, Jean Dimitrijevic and Michel Weill that was active from 1952 to 1985. It later took the name of "Atelier d'Etudes Architecturales" (ATEA) (Architectural Studies Workshop) with the addition of Paul Cordoliani, Henri Coulomb (1927–2006), Renzo Moro and Ivan Seifert (1926–2008). The studio originated many public buildings in France and Africa.
Guy Lagneau (1915–1996) and Michel Weill (1914–2001) met in the studio of Auguste Perret in the National School of Fine Arts established in 1943. They participated with Perret in the reconstruction of Le Havre from 1946, work that was later declared a World Heritage Site by UNESCO. Laigneau was particularly influenced by Scandinavian architecture, especially steel. Jean Dimitrijevic (1926–2010) joined the agency in 1947 after meeting Guy Lagneau in a Fine Arts workshop he was running. He graduated in 1957 and completed his training at the Massachusetts Institute of Technology in 1959. He then became a partner of the workshop.
The architects created the ATEA in association with a consulting firm, Société d'études techniques et d'aménagements planifiés (SETAP). ATEA-SETAP was involved in many planning operations in Africa, including Guinea, Mauritania and Senegal. At the same time, they accepted numerous public commissions from museums, prefectures, and shopping centers in France. Lagneau also participated as an individual in preparation of master plans and urban development in the Paris region between 1962 and 1965, contributing to creation of new towns.
On many occasions the agency worked with Jean Prouvé in creating innovative metal structures and with the designer Charlotte Perriand for interior design.