Moisture and humidity will be the worst enemy (other than nibbling children!) of your gingerbread house, so be sure to display it in a cool, dry place. It is not wise to choose the top of your telly or the fireplace, as the heat may misshape the house or make the sweets drop off. The recipe I am using gives gingerbread with a strong spicy scent that will fill your living room and last for weeks. For me, that is truly the scent of Christmas; cloves and ginger.
Properly sealed and protected, it is actually possible to keep a gingerbread house for years. For long time storage for example from after Christmas to next Christmas a sturdy cardboard box is probably the best choice. Put the house carefully in the box and use cotton wool to protect the corners. Wrap the box in a plastic bag or a large plastic sack and seal well to keep out moisture and avoid visitors like mice and insects. Store in a cool airy place. For non-edible creations, spray with a clear lacquer (available at craft and hardware stores). You may need several coats for maximum protection.