The operation consists of the general restoration of the stonework, roofing and mosaics of the 15 chapels. This restoration was accompanied by the implementation of accessibility for disabled people and a reorganisation of the services on the site.

The basilica of Lourdes, with its terraces and large ramps, is an exceptional monumental ensemble. The work still in progress concerns all of the structures built at the end of the 19th century. They ensure the stability and durability of the monument as well as the enhancement of the immense interior decorated surfaces, including the creation of new exterior mosaics.

The masonry work concerned the large ramps, the terraces (with waterproofing), the retaining walls, the elevations of the upper basilica, as well as the spire of the bell tower. The roofing work was carried out on the lead structures of the domes (75 tons were used) and the slate roofs of the upper basilica. This includes all the structural supports of the domes, nave and aisles. The two lead belfries were restored in 2021.

On the large interior decorations, more than 2,500 sqm of mosaics were restored to their original layout in the choir, the organ case and the eastern gallery. In addition, the west façade was fitted with mosaics by the artist P. Rupnick in 2010.