Three periods of works mark the construction of the church in Nant: the first was the apse, the apsidoles and the transept, the second was the nave, the third was the western masonry work. The study of the architecture shows the history of the works from the east to the west. Starting with the oldest part, around 1070, (the chevet and the transept), and after an interruption of a short time, the nave walls were built in 1080-1090. Then the construction of the western masonry work and the vaults in the nave, after 1140-1150. (Anne-Marie Pécheur).