The invention relates to facility including a robot (2) for supplying pallet preparation stations with products (3) of the crate type or different. The structure of the facility includes side walls (11) and doors (13, 14) for accessing the palletization stations A and B. The structure further includes a fixed wall (15) separating stations A and B, and a cowling (20) mobile from one station to the other and in the shape of a dihedron, for alternatively converting each palletization station A and B into a kind of pallet hatch, wherein said conversion is carried out automatically before the opening of the door for accessing a loaded pallet located in said hatch. The cowling (20) is directly actuated by the product handling robot (2).