Look up Casati, there's a great graphic novel about her or read articles on the internet about the 1920s Lady Gaga. A Marquise, a fascinating lady who spared no expense in making this her dream house. This building has a fascinating history, built by a shipping mandate, owned by a count who threw lavish parties (guests included- Debussy, Colette, Rodin, Sarah Bernhardt, Jean Cocteau) then Casati who lost it all in the 30's.
The building was modeled after one of the Versailles buildings (Trianon, Josephine's own place IIRC).