Caveau Communal ~ Temporary Communal Vault, Toulonjac, France.
Depositoire ~ Depository, Cahors, France
The following information comes from Condoleances.com a very helpful French website that sells floral tributes, but also gives information on everything else you need to know about French Funeral Customs
Translated by Google and slightly edited by me..
Temporary Homes for Coffins: The Depository disappears in favour of the Temporary Vault.
In 2011, the National Assembly decided to outlaw the use of cemetery mortuaries, those locations which are above ground level for hosting coffins pending transfer to a permanent home. Now only temporary vaults will receive coffins.
When a new vault has not been completed or no box at the columbarium is available, it is possible to place a coffin for a limited time in a Temporary Communal Vault in a cemetery.This action may be taken pending a final burial or cremation.
By Article R2213~29CGCT the members of parliament decided to eliminate the use of temporary morgues as destinations for coffins in order to avoid violations of safety standards. These Temporary Communal Vaults are legally required to be located within the cemetery.
The temporary vault is intended to accomodate a coffin before final burial and must be able to follow certain rules of decency and safety, including a reasonable sense of welcome. Moreover, it must provide adequate protection against any external damage such as severe weather conditions or voluntary degradation. The law requires the temporary vault to be equipped with a mechanism for closing the coffin away without any accident.
The period of storage within a temporary vault cannot exceed a period of six months. After this time and in the absence of any opposition, the town will be able to proceed with the burial or cremation of the deceased. The use of temporary vaults may be available free of charge in some towns.