He is the author of the interiors designs such as the emblematic Portuguese Nacional Library, the Calouste Gulbenkian Foundation, the Teatro Villatret, the Estoril Casino, the Belém Cultural Centre, or even the recent Casa da Música. The author of the first serial Portuguese designs ever made, such as the metal office furniture produced at Metalúrgica da Longra in the 1960s. "He is one of the first designers to be invited to work in a factory and to do so using the project design methodology", says João Paulo Martins, who was commissioner of the exhibition Daciano da Costa Designer, organized by the Fundação Calouste Gulbenkian in 2001. The work carried out by the collaboration with Longra, since 1961, was to last more than 30 years, says João Paulo Martins, one of the most productive relations of the national industry with design - "the Cortez line entered the imaginary of the Portuguese work space."

His office furniture has become a contemporary classic. He created environments in the interior spaces of the Biblioteca Nacional and in Gulbenkian. His work integrates interior architecture, furniture design, industrial, exhibition, and graphic, as well as scenography and costumes.