The new church had to be both a memorial to the memory of the war victims and a sanctuary dedicated to Saint Joseph. During a meeting concerning the architecture of the future church, Jacques Tournant showed the parish priest drawings Perret had made before the war for the Joan of Arc Church project. Once the Church Authorities granted approval and the Ministry of the Reconstruction its support, Perret and his team could get started on this monumental project.
Lantern tower of the city
During construction, war damages did not cover the whole cost, but Auguste Perret, pleading the double character of the building, both church and memorial, obtained extra funding. The preliminary drawing of 1951 shows a church with a structure similar to that of the Saint Joan of Arc project. After Auguste Perret died in February 1954, architects Georges Brochard, Raymond Audigier and Jacques Poirrier finished building the church and translated in stone Perret’s wishes for the shape of the tower.
With a base in the shape of a Greek cross, the height and outline of the church fit perfectly into the new urban environment created by the Perret Studio. The volumes of the church are made of two terraces, 17 and 24 metres high, a pyramidal structure raising up to 35 metres, dominated by the cylinder of the tower culminating at 110 metres. The church is built on a centred plan, where the “lantern tower” forms one body with the nave. The square plan, with a 40,60 metre side, is completed by two projecting parts: a small one to the east (forming the sacristy and winter chapel) and to the west (forming the main entrance and tribune).
Within Perret’s architectural language, the main order is here formed of four groups of four pillars each, supporting the lantern tower, whose cross section goes from square to octagonal. The lower part of the church (nave, aisles, apse), topped by a cornice, makes up the secondary order. Fluted columns 15 metre high (0,60 metre in diameter) bear the roof (a crisscrossing of beams bearing a prefabricated flooring), while posts make up the main structure of the façades. Saint-Joseph’s Church is essentially composed of four groups of sturdy pillars supporting the orthogonal tower through the means of four V shaped braces. Set at each angle of the square shaped nave are four groups of four square pillars; each is 25 metres high, 1m30 on each side, and stands 5 metres from the others. Each group sits 17metres away from the others. Crosspieces stabilize the groups of pillars at their top. Beams set on top of the pillars bear the tip of the V shaped braces which support the tower at their other end.
Transition from the square central plan of 22 metre on each side to the octagonal sided tower is made by way of a truncated pyramid. On top of it sits a ring beam bearing the trunk of the tower. Above this platform, the belfry is made of posts extended by the octagonal tower, jutting out at regular intervals, progressively tapering it up to the central lantern finishing at the topmost cross. From the truncated pyramid the tower, 13, 50 m in diameter and 40 m high, is hollow. A helical staircase, rising along one of the interior rib of the lantern tower, leads to the bells room.
The doubled outside walls of the church are made of rib posts with alternating in-fills: claustras or solid stone. All the concrete used has no finish outside as well as inside. The floor is simply covered in cement. Rose tinted bush-hammered in-fill panels have frame of posts and cornices with claustra openwork.
The church itself sits a bit lower than the esplanade at street level. From the entrance, one automatically looks up towards the top. Perret wished for a golden light, becoming lighter as one’s gaze rose. The openwork of the tower and the progression of light from the low part of the church towards the top add importance to the central plan adopted for the nave. The number of pieces of glass increases proportionally with the height: the lower part only holds one glass panel out of two whereas the high part is a well of light. The shape of the tower allows an exceptional quality of lighting of the inside. The prefabricated claustras, without a frame, hold a piece of white glass on the outside and a piece of coloured glass on the inside. The stained glass pieces are grouped vertically forming walls of light: 12 768 pieces of coloured glass were used to cover a 378m2 surface.
Auguste Perret had this idea to use the extreme resistance of concrete in order to create vast areas without intervening pillars. The church covers a 2 000m2 surface for a 50 000m3 interior volume. 4 200 000 m3 of concrete were used to build it, that is 50 000 tons of concrete.
Having done a study of the deep layers of ground and a variety of tests, a final calculation of foundation requirements was established. The foundation block base is set on 71, 15 m long, Franki piles. The sixteen pillars were set on as many wells of “Bénoto” reinforced concrete tubing, 1,45m in diameter and 15m deep. A 6,50 m2 sole plate, 2 m high, links each four pillar group at ground level. A considerable amount of weight is borne by those very sixteen points. The lantern tower exerts a weight of 1 100 tons at each angle. Because of the variety and intensity of pull forces at work at the junction between tower and frame, all tie rods were prestressed using the Freyssinet system (STUP trade licence). At the base of the truncated pyramid, on the four sides of the square, prestressed concrete tie rods were used. According to the weather, the structure as a whole is compressed at a variable rate which is never nil. Auguste Perret and his team managed to create a very high building, light and delicate in appearance, but able to withstand hurricanes. An extremely complex building plan was set up in order to build this church.
A work of art above all
Following the taste of the time and the will of both the architect and the parish priest, the Abbé Marie, no paintings decorate the church, whose aspect remains intentionally harsh. Perret aimed at renouncing “decorative art” to reach a constructive art of both simplicity and nobility. The stained glass windows of Saint Joseph’s are in total accord with the architecture. They were conceived, with Perret’s wishes in mind, by Marguerite Huré who had already worked with him on the Raincy Church project. Antique blown glass was used: of irregular thickness (2 to 5 mn), of subtle hues, it was mouth-blown as it used to be in the Middle-Ages, in Saint-Just-sur-Loire. The pieces of glass are set out in strictly geometrical patterns; a selection of seven main colours is used (orange, yellow, green, purple, red, greenish and white), declined in so many nuances to reach a number of fifty. At the basis of the tower, the walls hold the strongest harmonized hues: the darker pieces of glass give the impression that the light comes from above. In a similar fashion, the red and dead wood colours are on the north side, green and purple to the east, golden shades to the south, pink and orange shades to the west. Following the principles of the revival of sacred art, colours symbolize religious feelings with no added iconographic support.