Celebrity residents of Paris' Saint Louis island went to court Friday to try to stop a Qatari family from renovating a pristine 17th-century mansion in the historical district on the River Seine. A Qatari man bought the Hotel Lambert in 2007, receiving an official green-light in June for building works inside the listed building, one of the gems of the island just opposite Notre Dame Cathedral. But residents fear the Qatari plans - which have been watered down but still involve destroying an original staircase and putting in three elevators - would wreck one of the capital's best-preserved buildings. Some 8,000 people have signed a petition to defend the Hotel Lambert, launched by the Paris Historique heritage group, which hoped to obtain a fast-track court ruling on Friday to block the works. Backers include the French singer and songwriter Georges Moustaki, the 1940s movie star Michele Morgan - who lived in the mansion for 20 years - and several historians from the prestigious Academie Francaise. Built in the 1640s at the eastern tip of the island, the Hotel Lambert was designed for a rich financier by the French architect Louis Vau, who went on to oversee a major expansion of the Chateau de Versailles for Louis XIV. Ranged around a central courtyard garden, it is considered one of the finest examples of mid-seventeenth-century domestic French architecture. The owner acquired it from the Rothschild banking family in a deal worth an estimated 60 million euros ($86 million).