José Carlos Loureiro has been practising architecture since 1947, when he established his first office, without legal formalities and using his own name. The office was in Porto, at Praça Filipe de Lencastre, number 22, 6th floor, room 102.
In the 1960s he moved to a new office in the Lima/Luso Buildings. In 1972 he committed himself to architecture. In 1976, in partnership with the architect Luís Pádua Ramos, with whom he had been collaborating since 1955, he established GALP - Gabinete de Urbanismo, Arquitectura e Engenharia, Lda., (commercial enterprise) but he kept working in his office. In 1982, his son José Manuel Loureiro, also an architect, joined the partnership.
Among the architects José Carlos Loureiro worked with in his office were Alcino Soutinho, Anni Gunther, Carlos Chaves de Almeida, José Gomes Fernandes, Luís Cunha, Manuel Correia Fernandes, Maria Noémia Coutinho, Noé Dinis (trainee), Pádua Ramos and Rogério Cavaca (trainee).