The original plan called for a country residence surrounded by gardens, modeled after the Grand Trianon Palace at Versailles, designed by Jules Hardouin Mansart, the chief architect of Louis XIV. The Italian architect Lorenzo Giardini made the first plan, but he died in 1722, having made little but the first sketches. The project was taken over by Pierre Cailleteau, also known as Lassurance, who had been an assistant to Hardouin-Mansart. Cailleteau had worked on the palace of Versailles and Les Invalides, and knew the royal style very well, but he died in 1724. He was replaced by Jean Aubert, also a former assistant of Hardouin-Mansart. Aubert had built one of the grandest projects of the time, the stables of the royal residence at Chantilly. In the meanwhile, the construction of the neighbouring Hôtel de Lassay had begun, following a plan by another noted architect, Jacques Gabriel, the designer of the buildings around the Place de la Concorde. Both buildings were finished in 1728.