Combined seating and sleeping furniture and kit

A kit for an item of combined seating and sleeping furniture, comprising

• a base body, in which a storage space is formed;
• and
• a lid which is mounted on the base body in such a manner that the lid is displaced between an open position in which a lid-side opening of the base body is open towards the storage space and a closed position in which the lid-side opening of the storage space is closed;
• wherein the lid has a seating surface on one flat side and an arrangement of spring elements on an opposite flat side of which a resilient mattress support surface is provided for a lying mattress;
• and
• wherein the lid after arrangement on the base surface is displaced between a first closed position in which the flat side with the seating surface is arranged on the outer side and a second closed position in which the opposite flat side with the arrangement of spring elements is arranged on the outer side.