On the walls of the Sert, Jackson and Associates offices hung, within sight of the employees, sheets displaying the Modulor series. Josep Lluís Sert, the firm’s founding partner, had been using the measurements as a reference since 1951, on a host of projects that ranged from his own home to entire housing developments in South America. Before establishing himself as one of the pioneers of architectural modernity in Republican Spain, Sert had worked for Le Corbusier. Following the installation of the Francoist dictatorship, he moved to the United States. In 1969, he received a commission from Joan Miró to design an arts centre in Barcelona dedicated to his work and temporary exhibitions by other contemporary artists. It was not Sert’s first time working for Miró; a decade earlier, he had designed the Catalan artist’s workshop on the Son Abrines estate in Palma de Mallorca.

The Centre d’Estudis d’Art Contemporani – Fundació Joan Miró opened its doors in 1975. This building-fortress sits on an esplanade on the north-east face of Montjuïc mountain. The exhibition rooms surround a square patio overlooked by an olive tree and the roof forms a concrete case, ruled by a combination of ribs, semi-circular arches, lintels and window-skylights. The building’s dimensions obey the Modulor system: the side of the central patio measures 15.50 metres, the rooms are 7.73 metres wide, the foyer 5.92 metres, the ceilings are 3.66 metres high, the ribs in the roof are repeated every 1.13 metres, the shelves are arranged at 43 and 70 centimetres, etcetera.

In 1984, a year after Sert’s death, a proposal to extend the Fundació was requested from Jaume Freixa, who was the head architect on the original project. Freixa decided to mimic the original design in this extension. He used the same shapes and materials – concrete, artificial stone and ceramic tiles – as those used for the building finished in 1975 and continued to apply the Modulor system. Four years later, the new exhibition rooms, a series of offices, and a second patio of golden proportions enclosed by a restaurant were finished. The year 2001 saw another extension of the exhibition space, led by Freixa and following the model of the original project.