Article R2334-28 of the French General Code of Local Authorities
If, on expiry of a period of two years from notification of the grant, the operation in respect of which it was awarded has not begun to be carried out, the prefect shall declare that his decision to award the grant has lapsed. However, in the case of operations that can be carried out in the short term, the Prefect may set a time limit of less than two years….