Office for Metropolitan Architecture

Rem Koolhaas and Elia Zenghelis started working together in the early 1970s at the Architectural Association, the London-based architecture school, where Koolhaas was a student and Zenghelis an instructor. Their first major project was the utopian/dystopian project Exodus, or the Voluntary Prisoners of Architecture (1972). This project proposed a linear structure, cutting through London like a knife. Other projects included City of the Captive Globe (1974), Hotel Sphinx (1975), New Welfare Island/Welfare Palace Hotel (1975–76), Roosevelt Island Redevelopment (1975) – all "paper" projects that were not (intended to be) built, and all located in Manhattan, the subject of Koolhaas's book Delirious New York, A Retroactive Manifesto for Manhattan (1975).

OMA was founded in 1975 by Dutch architect Rem Koolhaas and Greek architect Elia Zenghelis, along with Madelon Vriesendorp and Zoe Zenghelis. The founding of OMA coincided with the firm's entry in the architectural design competition for a new Dutch parliament building in The Hague in 1978, with Zaha Hadid. OMA was one of the first-prize winners (among some 10 others), and the project was widely discussed and published. The commission, however, was given to an architect who did not participate in the competition. The entry for the Dutch parliament competition was the first of a series of controversial and successful international competition entries by OMA in the 1980s that were not built by OMA.

OMA in the 1980s

OMA's first major commissions were The Netherlands Dance Theatre (1981) in The Hague and IJ-Plein Urban planning (1981–1988) in Amsterdam. Due to change of location a second design for the Dance Theater was made in 1984. Once completed in 1987, the building received international attention. Although full of "first mistakes", the Dance Theater is the first realized design in which the ideas of Rem Koolhaas were made apparent. IJ-plein is located at Amsterdam's IJ, a river that serves as the city's waterfront, opposite the city center. The master plan consists of 1,300 dwellings and several facilities. OMA designed the school, the community center, and two blocks of housing.

A few other designs were realized in the 1980s: a police station in Almere (1982–1985), a bus station in Rotterdam (1985–1987, demolished in 2005), Byzantium apartment block in Amsterdam (1985–1991) and Checkpoint Charlie Housing in Berlin (1984–1990). Two houses were built in this period; the first house was a duo of patio villas (1985–1988) in the style of Mies van der Rohe, inserted in a dike in Rotterdam. The second – arguably the most full-grown design of OMA until that date – was Villa Dall'Ava in Paris (1984–1991). The client, according to Koolhaas, asked for a "masterpiece". He wanted a glass house. She wanted a swimming pool on the roof. So many delays plagued the house that it "became a record of our own (OMA's) growing up".

Several studies were made during the late 1970s and 1980s: Study for the renovation of a panopticon prison in Arnhem in 1979, Boompjes tower slab in Rotterdam (1979), Housing for Berlin IBA (1980, not realised, and the reason OMA would not design anything in Berlin anymore in the 20th century, the Dutch Embassy Building being the comeback), master plan for a world exhibition in Paris (1983). Much more important however were the competition entries OMA designed in this period. They gained the office international fame (but not one design was actually built).

OMA in the 1990s

In the 1990s OMA gained renown through a series of groundbreaking entries in major competitions: e.g., Tres Grande Bibliothèque and Two Libraries for Jussieu University, Paris, France (1993). During these years OMA also realized ambitious projects, ranging from private residences to large scale urban plans: Villa dall’Ava, Paris, France (1991), Nexus Housing, Fukuoka, Japan (1991), Kunsthal, Rotterdam (1992).

The Euralille (1994), a 70-hectare business and civic center in Lille, northern France comprising the European hub for high-speed trains, transformed a once dormant center of more than 50 million inhabitants into a site offering connectivity, and a range of contemporary activities.

In 1999 OMA completed the Maison à Bordeaux, a villa for a client in the hills outside Bordeaux, France. The villa's most striking feature is a platform in the very center of the house that moves freely between the three floors and allowed the client to move with his wheelchair on all three levels of the villa. The design was conceived in collaboration with engineer Cecil Balmond.