To build the new convent, he obtained more land next to the old chapel and commissioned the architect Charles Errard to design and construct a new church.

[1] When his plan was finished, Errard returned to Rome, and delegated the supervision of the construction to a M. Cheret, the director of public works.

The new convent of "Les Dames de l'Assomption" became a refuge into the religious life for well-born women from the Royal Court.

On May 22, 1834, the funeral of General Lafayette was held in the church, in the presence of the Garde National and the French parliament.

The dome is supported by eight groups of Pilasters with Corinthian columns On the upper level are eight high windows, separated by panels of moulded stucco.

[4] His other organs included the Saint-Denis Basilica (1841), Église de la Madeleine, (1859), Saint-Sulpice church, and Notre-Dame Cathedral[5]