Luigi Moretti graduated in 1930 with a project for a college of classical high education in Villa dei Papi, near Grottaferrata (Rome). Between 1931 and 1934 he worked as assistant to the chair of Vincenzo Fasolo of History and Styles of Architecture and to the chair of Gustavo Giovannoni for Restoration of Monuments, subsequently collaborating with the archaeologist Corrado Ricci as part of the three-year scholarship of Roman studies. Studies for the arrangement of the Trajan’s market area belong to this period.

In contact with Renato Ricci, president of the Balilla National Opera, in 1933 he obtained the task of directing the technical office. For the institution he designed the Youth House in Piacenza, the Trastevere House in Rome, the Trecate House, the Women’s House in Piacenza and, in 1937, the Youth House in Urbino and Tivoli.
In 1936 he was commissioned to draw up the regulatory plan of the Mussolini Forum, previously entrusted to the architect Enrico Del Debbio. In the same area, he created the experimental Casa Balilla, then the fencing academy, the Palestra del Duce and the commemorative cell. In 1934 he participated in the national competition for the Palazzo del Littorio and for the exhibition of the fascist revolution and was chosen for the second degree race, obtaining a special mention. The ability to combine tradition and modernity in his works solicit explicit acknowledgments.
In the interview granted to Luigi Diemoz at the age of twenty-nine, published in «Quadrivio» (December 1936), he anticipates some concepts related to the architecture that he will develop in the course of his activity. In Rome, in the meantime, the great project related to the Universal Exposition scheduled for 1942 has started: in 1938 Moretti wins, ex aequo with Muratori, Fariello and Quaroni, the competition for the imperial square and in the context of the final project, he deals in particular of the Gran Teatro, whose construction was interrupted due to Italy’s entry into the war.
Since the beginning of the war Moretti suspends his activity and the news for this period is somewhat incomplete and fragmented. In 1945 he met Count Adolfo Fossataro. Together they founded the company Cofimprese and built three hotel houses in Milan, which would become a classic of this new building typology, a building complex for offices and homes in Corso Italia and in Rome, between 1947 and 1951, a residential building for the Astrea cooperative and the Girasole building. After these first realizations, the Cofimprese dissolved.
From this moment Moretti resumed a fervent activity not only in the field of architecture but also as a scholar and art critic: in 1950 he founded the magazine “Spazio” and in 1954 in Rome, with Michel Tapié, he created the gallery of the same name.
The activity of the following years is rich and diversified: he receives assignments from private individuals, public administrations and institutions of national importance. He draws up plans for the new urban park coordination plan and represents the Ministry of Public Works in the drafting committee of the Rome inter-municipal plan.
In 1958 he designed, also in collaboration, important residential districts: the Olympic Village, which received the IN / ARCH 1961 prize for the best construction in Lazio region, the Cep district of Livorno and the Incis district of Decima in Rome.
He received significant awards: in 1957 the Giovanni Gronchi national architecture prize, established by the Accademia Nazionale di San Luca, in 1964 the gold medal of merit of the school, culture and art by the Head of State , receives the prize conferred by the Institute of Architecture of Saint Louis and is nominated honorary member of the American Institut of Architects, he is elected academic of the Accademia Nazionale di San Luca.
Since 1957 he has been an external consultant to the General Real Estate Company on behalf of which, in 1960, he began work on the project for the Stock Exchange Tower of Montreal and for the Watergate residential complex in Washington. The two works contribute to affirm the architect’s fame in the international panorama.
In 1957 he founded the Irmou (Institute of Mathematical and Operational Research for Urban Planning) with the intent to carry out his theories on “parametric architecture”, aimed at applying mathematical theories in design. As president of the Institute, he will be called to be part of numerous commissions and will attend conferences and debates on urban issues.

Among the works planned during the sixties, the San Maurizio building in Monte Mario, the two twin buildings in the Eur district in Rome, the headquarters of ESSO and the General Real Estate Company, for which it wins the regional prize IN / ARCH 1966 , the new arrangement of the Baths of Bonifacio VIII in Fiuggi, the project for the Termini-Risorgimento trunk for the new Rome underground, the “Pietro Nenni” bridge, with the engineer Silvano Zorzi, and the Villa Borghese underground parking.
In 1968, the project for the sanctuary on Lake Tiberias, in Tagba in the Holy Land, was approved by the Holy See, but the works do not begin due to the war events that erupted in the area between Israelis and Palestinians.
Meanwhile, he extends his professional activity to other countries: Kuwait and Algeria, where he starts a series of projects that will be completed by his studio collaborators, the architects Giovanni Quadarella and Lucio Causa and the engineer Pierluigi Borlenghi.

Luigi Moretti, despite the important commitments in the field of design, does not abandon his other numerous interests. He participated in the international conference of Michelangelo studies (1964) with the essay “The ideal structures of Michelangelo and Baroque architecture”, and produced a film on the life of Michelangelo who received the Film d’Arte award at the Venice Biennale, in 1967 he held a lecture at the Accademia Nazionale di San Luca on Borromini’s series of generalized structures.
In 1967 he received the Prix d’Excellence Design Canada and in 1968 the Antonio Feltrinelli prize from the Accademia Nazionale dei Lincei. In 1968 the publisher De Luca published 50 images of architectures by Luigi Moretti, with the preface by Giuseppe Ungaretti.