Article 977 of Civil Code

1 - A formal mortgage includes the appurtenances of the mortgaged immovable that are deemed immovable property. 2 - It includes, in particular, buildings and trees existing on the mortgaged immovable at the time of the mortgage or introduced thereafter, easements, immovables by destination, and all improvements and constructions made on the mortgaged immovable, all unless otherwise agreed and without prejudice to the privilege securing amounts due to contractors or engineers.