The Bouygues Bâtiment Ile-de-France subsidiary of Bouygues Construction refurbished architectural features and structures in the former Orsay train station, converting it into an approx. 45,000 m² space for art and exhibitions. The museum was built in a spectacular fin-de-siècle style. The RER line running under the site meant that Bouygues Construction had to strengthen foundations and build new vertical structures to separate the RER station from the museum building.