The school settled on the site of the former convent of the Carmelites, however the premises were not well adapted. Gabriel Ruprich-Robert developed a new project for the site; however, due to a lack of sufficient funds, he decided to renovate some of the old buildings instead of destroying them. The first phase of the renovation took place between 1894 and 1897. Following the French law establishing the separation of the church and state, ownership of the premises was given to the state. In 1927, the premises were repurchased by the institute, allowing the second phase of the renovation to take place between 1929 and 1930, followed by a third phase between 1932 and 1933.