In 1960, Eugène Claudius Petit and the parish committee asked Le Corbusier to design a church for the Firminy-Vert district. He worked on the plans with the assistance of José Oubrerie and José Luis Miquel until 1965. Three years after his death, the "Le Corbusier pour l’église de Firminy-Vert" (Le Corbusier for the church at Firminy-Vert) association was created in order to bring together the funds necessary for its completion.
The first stone was laid down in 1970, but construction only began in 1973, and finally came to an end in 1978. The parts that were built (the current interpreting centre) were awarded Historical Monument status in 1996. It was not until the beginning of the following decade that the decision was made to finish construction. It was largely financed by the Communauté d’Agglomération de Saint-Etienne Métropole, which declared in 2002 that it was of community importance to complete the monument.
The work, which was finished in November 2006, was supervised by José Oubrerie, and respected the original project design. He was assisted by Aline Duverger, Yves Perret, Romain Chazalon, as well as by Jean-François Grange-Chavanis, head architect for historical monuments. It was produced using modern techniques and materials.
The building has a square base with sides of 25.50 metres in length, which expands into a truncated cone 33 metres high.
The shell, made from self-compacting concrete, houses the nave. It is orientated to the east of the constellation of Orion. The system for rainwater recovery works all the way around the building. It covers horizontal loopholes which follow the spiral movement of the sun to the interior of the nave. The 3 “light cannons”, fitted on the top and on the west façade comprise a device that is specific to Le Corbusier’s architecture
The church of Saint-Pierre de Firminy-Vert is a double building: a platform which is largely open to the light, which aims to give lightness to the building, contrasting with the shell made from solid concrete.
Le Corbusier had designed the lower part for parish activities (meetings, catechisis) as well as for the priest’s offices. Nowadays it is an interpreting centre dedicated to Le Corbusier’s works.
The upper part was entirely taken up by the nave with two chapels: the one used during the week with a secondary altar (entering on the left) and the one used on Sundays with the main altar. The latter is connected to the ground via a white pillar, separate from the building’s structure.