In Ruiz, the defendant entered a trailer that was parked against the loading dock of a factory. The trailer was not attached to a truck when the defendant entered it, although it sat on eight rear wheels and could be mobilized by connecting a truck to it. A salvage company owned the trailer and hauled it away when the trailer became filled, which happened roughly every three months. This court held that, under section 19--1(a), the trailer was a "building" that could be the object of a burglary. the Court emphasized that our courts had construed the term to include a considerable variety of structures, the key being that all these structures served to shelter people or property. The Court concluded that the trailer was therefore a building, as it served to store and shelter the scrap metal that the factory sold the salvage company. The mere fact that the use of the trailer for this purpose was temporary did not detract from the essential character of the use. Ruiz, 133 Ill. App. 3d at 1068-69.