The construction company were called in to Chateau Bellevue in the Bordeaux region to tear down an outhouse and renovate the rest of the house.
However, The AP reports that the builders instead bulldozed the whole property, belonging to Russian businessman Dmitry Stroskin.
Stroskin, who is based in Poland, has claimed he will build a replica of the stately house, vowing to a newspaper he will "rebuild Bellevue exactly as it was".
The house had previously been rented out for weddings and functions. The rebuilding contract is expected to be worth €1.5m (£1.21m).
Locals aired doubts that the demolition was actually a mistake as Stroskin claims, but village mayor Claude Carty said that Stroskin "told me that he was really surprised, that this was an accident and he was the principal victim".