In the summer of 1904, Brother André began the construction of an oratory to pray to Saint Joseph. The first chapel erected on Mount Royal measured only 4.5 meters by 5.5 meters (15 feet by 18 feet). It could be described as an oratory, that is, a place of prayer of modest size. Its original location was lower down, on the current site of the crypt.

The original building is the choir of the current chapel. The altar, sculpted by Brother Abundius Piché, c.s.c., during the winter of 1906, is surmounted by a statue of Saint Joseph carrying the infant Jesus. The inscription “Go to Joseph” crowns the retable.

The ex-votos were offered as a sign of gratitude by individuals whose prayers were answered. Under the bell tower, the patron saints watch over: Saint Joseph, Saint John the Baptist, and Saint Patrick.

Above the original chapel is a small room where Brother André stayed at the beginning of the work. Formerly, the interior staircase of the chapel provided access to this room. Here one discovers the simplicity of the furniture, books, and religious objects. A monument erected in 1955, the work of sculptor Émile Brunet, pays tribute to Brother André.