René Sergent studied under the engineer Émile Trélat at the École Spéciale d’Architecture. In 1884, he joined the practice of Ernest Sanson, considered the best architect of private homes at that time. Under Sanson’s guidance, Sergent became fascinated by the works of French architects from François Mansart to Alexandre-Théodore Brongniart, and particularly by those of Jacques Gabriel and his son Jacques-Ange. Sergent witnessed the completion of Sanson’s masterpiece, the “Palais Rose” of Boniface de Castellane.
Around 1899, Sergent launched out on his own. He had earned the admiration of Comte de Fels, who turned to Sanson’s agency for the construction of the Château de Voisins and had the project entrusted to Sergent. Making a clean break with the previous generation’s zealously original but soon outdated style of architecture, and venturing even further in terms of comfort and practicality, he gained renown for his highly classical mansions and châteaux.
He was particularly prolific in the first fifteen years of the twentieth century, building in Buenos Aires, New York, Santa Fe and London, where he extended and refurbished the Savoy and Claridge’s.
His work in Paris includes several mansions – such as those of the great couturier Jean-Philippe Worth at 4, avenue Émile-Deschanel by the Champ de Mars, of Otto Bemberg at 28, rue Émile-Ménier and of the Duveen brothers at 20, place Vendôme – not forgetting the famous Trianon Palace Hotel in Versailles.
He built Moïse de Camondo’s mansion at 63, rue de Monceau from 1912 to 1914, and took charge of its maintenance and renovation until his death.
In 1921, he took on the architects L. Fagen and R. Bétourné as his associates, and they continued his work after 1927 with the Sergent architecture agency.